HP Array Controller HSG V8.7 Software User Manual

DIGITAL HSG8 0 Array Controll er ACS Version 8 .2
EK-HSG80-UG. B01
Digital Equipment Corporation Maynard, Mass achusetts
User’s Guide
July 1998
Commercia l Comp uter S oft wa re , Com puter Sof tware Doc ument at ion an d Techni ca l Da ta for Comm erci al It ems ar e licensed to the U.S. Gover n m en t w it h D IGITAL’s stand a rd co m me rcial lice ns e and, when applicable, the rights in DFAR 252.227 701 5, “Te chnical Data—Comm ercial Items. ”
© Digital Equipment Corporation, 1998. Printed in U.S.A. All rights reserved.
DIGITAL, DIGITAL UNIX, DECconnect, HSZ, StorageWorks, VMS, OpenVMS, and the DIGITAL logo are tradema rks of Digital Equipm ent Corporatio n.
UNIX is a regist ered tradem ark in the U nited States and other countries exclusively through X/Open Company Ltd. Windows NT is a trademar k of the Micr osoft Corpor ation. Sun is a regis tered trademark of Sun Microsystems , Inc. Hewlett-Packard and HP–UX are registered trademarks of the Hewlett-Packard Company. IBM and AIX are registered tradem arks of International Busine ss Machines Corporation. All other trademarks and registered trade marks are th e pr operty of th ei r respect ive own er s.
This equipment has been tested and fo und to compl y with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This eq uipment generates, uses and can radiate radio fre­quency energy and, i f not installed and used in accordance with the manuals, may cause harmful interference to radio communications. Operation of t his equipment in a resid en tial area is likely to cause harmful interference in which case the user will be required to correct the int erference at his own expe nse. Restrictions apply to the use of the local-connection port on this series of controllers; failure to observe these restr ictions may result in harmful interference. Always disconne ct this port as soon as possible after completing the setup operation. Any changes or modifications made to this equipment may void the user's authority t o operate the equipment.
Warning! This is a Class A product. In a dom estic environment this product may cause radio interference in which case the user may be required to take adequate measures.
Achtung! Dieses i st ein Gerät der Funkstörgrenzwertklasse A. In Wohnbereichen können bei Betrieb dieses Gerätes Rund­funkstörungen auftreten, in welchen Fällen der Benutz er für entsprechende Gegen ma ßnahmen verantwortlich ist.
Avertissement! Cet appareil est un appareil de Classe A. D ans un environnement ré sidentiel cet appareil peut provoquer des brouil­lages ra dioélectriques. Dans ce cas, il peut être de mandé à l’ utilisateur de prendre les mesures appropriées .
Preface
Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xviii
Electrostatic Discharge Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xviii
Component Precaution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
Maintenance Port Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xx
T ypographical Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xx
Special Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxi
Required Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xxii
Related Publications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiii
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiv
Chapter 1 General Descri ption
The HSG80 Array Controller Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–2
Summary of HSG80 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–4
The HSG80 Array Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–7
Operator Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–13
Maintenance Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–14
Utilities and Exercisers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–14
Cache Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–18
Caching Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–20
Fault-Tolerance for Write-Back Caching . . . . . . . . . . . . . . . . . . . . . . . . . . .1–21
External Cache Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–28
Charging Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–29
iii
Chapter 2 Configuring an HSG80 Array Controller
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–2
Configuration Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–2
Configuring an HSG80 Array Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–3
Setting the PVA Module ID Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–6
Establishing a Local Connection to the Controller . . . . . . . . . . . . . . . . . . . . . . . .2–7
Selecting a Failover Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–10
Using Transparent Failover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–10
Using Multiple-Bus Failover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–11
Enabling Mirrored Write-Back Cache. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–12
iv
Selecting a Cache Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–12
Fault-Tolerance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–12
Backing up Power with a UPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–13
Connecting the Subsystem to the Host . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–14
Connecting a Dua l-Redundant Configuration to the Host. . . . . . . . . . . . . . 2–16
Chapter 3 Creating Storagesets
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–2
Planning and Configuring Storagesets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–4
Creating a Storageset and Device Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–5
Determining Storage Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–7
Choosing a Storageset Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–8
Using Stripesets to Increase I/O Performance . . . . . . . . . . . . . . . . . . . . . . . . 3–8
Using Mirrorsets to Ensure Av ailability. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–12
Using RAIDsets to Increase Performance and Availability. . . . . . . . . . . . . 3–15
Using Striped Mirrorsets for Highe s t Perfo rmance and Availability. . . . . . 3–17
Cloning Data for Backup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–19
Backing Up Your Subsystem Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–23
Saving Subsystem Configur ation Information to a Single Disk . . . . . . . . . 3–23
Saving Subsystem Configur ation Information to Multiple Disks . . . . . . . . 3–23
Saving Subsystem Configur ation Information to a Storagese t . . . . . . . . . . 3–24
Controller and Port Worldwide Names (Node IDs) . . . . . . . . . . . . . . . . . . . . . . 3–26
Restoring Worldwide Names (Node IDs) . . . . . . . . . . . . . . . . . . . . . . . . . . 3–26
Unit World Wide Names (LUN IDs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–27
Assigning Unit Numbers for Host Access to Storagesets . . . . . . . . . . . . . . . . . . 3–28
Assigning Unit Offsets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–29
Assigning Access Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–30
Creating a Storageset Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–32
Device PTL Addressing Convention within the Controller. . . . . . . . . . . . . 3–33
Planning Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–37
Defining a Partition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–37
Guidelines for Partitioning Storagesets and Disk Drives. . . . . . . . . . . . . . . 3–38
Choosi n g Sw i tches for Sto r a ge s e ts an d Dev ic es. . . . . . . . . . . . . . . . . . . . . . . . . 3–39
Enabling Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–39
Changing Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–39
RAIDset Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–40
Replacement Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–40
Reconstruction Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–40
Membership . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–41
Mirrorset Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–42
Replacement Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–42
Copy Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–42
Read Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–43
Device Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–44
Transportability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–44
Device Transfer Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–46
Initialize Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–47
Chunk Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–47
Save Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–50
Destroy/Nodestroy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–52
Unit Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–54
Configuring Storagesets with CLI Commands . . . . . . . . . . . . . . . . . . . . . . . . . .3–55
Adding Disk Drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–55
Configuring a Stripeset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–55
Configuring a Mirrorset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–56
Configuring a RAIDset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–57
Configuring a Striped Mirrorset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–59
Configuring a Single-Disk Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–60
Partitioning a Storageset or Disk Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–61
Adding a Disk Drive to the Spareset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–63
Removing a Disk Drive from the Spareset . . . . . . . . . . . . . . . . . . . . . . . . . .3–64
Enabling Autospare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–65
Deleting a Storageset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–65
Changing Switches for a Storageset or Device. . . . . . . . . . . . . . . . . . . . . . .3–66
Configuring with the Command Console LUN . . . . . . . . . . . . . . . . . . . . . . . . . .3–68
Enabling and Disabling the CCL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–68
Finding the CCL Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–69
Multiple-Port and Multiple-Host Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–69
Tro ubleshooting with the CCL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–70
Adding Storage Units: Where Is the CCL? . . . . . . . . . . . . . . . . . . . . . . . . .3–70
Moving Storagesets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–71
v
vi
Chapter 4 Troubleshooting
Maintenance Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–1
Tro ubleshooting Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–2
Troubleshooting Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–4
Significant Event Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–14
Events that cause controller termination . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–14
Events that do not cause controller operation to terminate . . . . . . . . . . . . . 4–15
Fault Management Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–17
Displaying Failure Entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–17
Translating Event Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–18
Controlling the Display of Significant Events and Failures. . . . . . . . . . . . . 4–20
Using VTDPY to Check for Communication Problems . . . . . . . . . . . . . . . . . . . 4–23
Checking Controller-to-Host Communications . . . . . . . . . . . . . . . . . . . . 4–24
Checking Controller-to-Device Communications . . . . . . . . . . . . . . . . . . . . 4–24
Checking Unit Status and I/O Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–29
Checking Fibre Channel Link Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–31
Checking for Disk-Drive Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–36
Finding a Disk Drive in the Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–36
T esting the Read Capability of a Disk Drive . . . . . . . . . . . . . . . . . . . . . . . . 4–36
T esting the Read and Write Capabilities of a Disk Drive . . . . . . . . . . . . . . 4–37
DILX Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–40
Running the Controller’s Diagnostic Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–41
Chapter 5 Replacement Procedures
Replacing Modules in a Single Controller Configuration. . . . . . . . . . . . . . . . . . . 5–2
Replacing the Controller and Cache Module in a Single Controller
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–2
Replacing the Controller in a Single Controller Configuration. . . . . . . . . . . 5–3
Replacing the Cache Module in a Single Controller Configuration . . . . . . . 5–6
Replacing Modul es in a Dual-Redundant Contr oller Configuration. . . . . . . . . . . 5–8
Replacing a Con troller and Cache Module in a Dual-Redundant Controlle r
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–9
Replacing a Con troller in a Dual-Redundant Controller Configuration . . . 5–15 Replacing a Cache Module in a Dual-Redundant Controller
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–21
vii
Replacing the External Cache Battery St o rage
Building Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–27
Replacing the External Cache Batte r y St orage Building Block
With Cabinet Powered On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–28
Replacing the External Cache Batte r y St orage Building Block
With Cabinet Powered Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–29
Replacing the GLM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–32
Replacing a PVA Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–34
Replacing the PVA in the Master Enclosure (ID 0) . . . . . . . . . . . . . . . . . . .5–34
Replacing the PVA in the First Expans ion (ID 2) or Second
Expansion Enclosure (ID 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–36
Replacing an I/O Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–39
Replacing DIMMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–42
Removing DIMMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–43
Installing DIMMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–44
Replacing a Fibre Cable or Hub. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–45
Replacing a PCMCIA Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–46
Replacing a Failed Storageset Member . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–47
Removing a Failed RAIDset or Mirrorset Member . . . . . . . . . . . . . . . . . . .5–47
Installing the New Member . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–47
Shutting Down the Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–48
Disabling and Enabling the External Cache Batteries . . . . . . . . . . . . . . . . .5–48
Restarting the Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5–50
Chapter 6 Upgrading the Su bsy stem
Upgrading Controller Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6–2
Installing a New Program Card. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6–2
Downloading New Software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6–3
Using CLCP to Install, Delete, and List Software Patches. . . . . . . . . . . . . . .6–6
Upgrading Firmware on a Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6–11
HSUTIL Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6–14
Upgrading to a Dual-Redundant Controller Configuration . . . . . . . . . . . . . . . . .6–16
Installi ng a Ne w Controller, Cache Module, and ECB. . . . . . . . . . . . . . . . .6–16
Upgrading Cache Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6–20
viii
Appendix A System Profiles
Device Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A–2
Storageset Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A–3
Enclosure Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A–4
Appendix B CLI Commands
CLI Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–2
Using the CLI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–2
Command Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–2
Getting Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–3
Entering CLI Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–3
Changing the CLI Prompt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–4
Command Syntax. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–5
ADD CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–7
ADD DISK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–11
ADD MIRRORSET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–15
ADD RAIDSET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–19
ADD SPARESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–23
ADD STRIPESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–25
ADD UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–27
CLEAR_ERRORS CLI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–35
CLEAR_ERRORS controller INVALID_CACHE . . . . . . . . . . . . . . . . . . . . . .B–37
CLEAR_ERRORS device-name UNKNOWN . . . . . . . . . . . . . . . . . . . . . . . . .B–39
CLEAR_ERRO RS u ni t-num be r LOST_DATA . . . . . . . . . . . . . . . . . . . . . . . . .B–41
CLEAR_ERRORS unit-number UNWRITEABLE_DATA . . . . . . . . . . . . . . . .B–43
CONFIGURATION RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–45
CONFIGURATION RESTORE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–47
CONFIGURATION SAVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–49
CREATE_PARTITION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–51
DELETE connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–55
DELETE container-name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–57
DELETE FAILEDSET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–59
DELETE SPARESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–61
DELETE unit-number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–63
DESTROY_PARTITION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–65
DIRECTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–67
HELP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–69
INITIALIZE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–71
LOCATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–77
MIRROR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–79
POWEROFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–83
REDUCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–85
RENAME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–89
RESTART controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–91
RETRY_ERRORS UNWRITEABLE_DATA . . . . . . . . . . . . . . . . . . . . . . . . . B–93
RUN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–95
SELFTEST controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–99
SET connection-name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–101
SET controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–103
SET device-name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–111
SET EMU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–113
SET FAILEDSET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–117
SET FAILOVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–119
SET mirrorset-name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–121
SET MULTIBUS_FAILOVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–127
SET NOF AILOVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–129
SET NOMULTIBUS_FAILOVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–131
SET RAIDset-name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–133
SET unit-number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–137
SHOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–143
SHUTDOWN controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–149
UNMIRROR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B–151
ix
Appendix C LED Codes
Operator Control Panel LED Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C–2
Solid OCP Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C–3
Flashing OCP Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C–8
Appendix D Event Reporting: Templates and Codes
Passthrough Device Reset Event Sense Data Response. . . . . . . . . . . . . . . . . . . . D–2
Last Failure Event Sense Data Response . . . . . . . . . . . . . . . . . . . . . . . . . . . D–3
Multiple-Bus Failover Event Sense Data Response . . . . . . . . . . . . . . . . . . . D–5
x
Failover Event Sense Data Respons e. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–6
Nonvolatile Parameter Memory Component Event Sense
Data Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–8
Backup Batte r y F ailure Event Sense Data Response. . . . . . . . . . . . . . . . . . .D–9
Subsystem Buil t-In Self Tes t Failure Event Sense Data Response . . . . . . .D–10
Memory System Failure Event Sense Data Response . . . . . . . . . . . . . . . . .D–12
Device Serv ices Non-Transfer Error Event Sense Data Response . . . . . . .D–13
Disk Trans f er Error Event Sense Data Response. . . . . . . . . . . . . . . . . . . . .D–14
Instance Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–16
Instance Code Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–16
Instance Codes and FMU. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–16
Last Failure Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–36
Last Failure Code Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–36
Last Failure Codes and FMU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–36
Recommended Repair Action Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–77
Component Identifier Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–82
Event Threshold Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–84
ASC/ASCQ Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–85
Appendix E Controller Specifications
Physical and Electrical Specifications for the Controller . . . . . . . . . . . . . . . . . . . E–2
Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E–3
Glossary
Index

Figures

xi
The HSG80 Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–3
A Host and Its Storage Subsystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–7
HSG80 Array Controller–Fibre Channel Copper Cabling. . . . . . . . . . . . . . . . . . .1–8
Optional Maintenance Port Cable for a Terminal Connection. . . . . . . . . . . . . . .1–10
HSG80 Array Controller–Fibre Channel Optical Cabling. . . . . . . . . . . . . . . . . .1–11
Location of Cont rollers and Cache Modules . . . . . . . . . . . . . . . . . . . . . . . . . . .1–13
HSG80 Controller Operator Control Panel (OCP). . . . . . . . . . . . . . . . . . . . . . . .1–14
Cache Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–19
ECB for Dual-Redundant Configurat ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–28
SCSI Target ID Numbers on the Controller Device Bus and PVA Settings
in an Extended Subsytem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–6
Terminal to Local- Connection Port Connection . . . . . . . . . . . . . . . . . . . . . . . . . .2–7
This Controller and Other Controller” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–9
Cabling for Sing le Configuration with Fibre Channel Copper Support . . . . . . .2–14
Cabling for Sing le Configuration with Fibre Channel Optical S upport . . . . . . .2–15
Cabling for Dual-Re dundant Configu ration with Two Hubs using
Fibre Channel Copper Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–17
Cabling for Dual-Re dundant Configu ration with Two Hubs using
Fibre Channel Optical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–18
Cabling for Dual-Re dundant Configu ration with One Hub using
Fibre Channel Copper Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–20
Cabling for Dual-Re dundant Configu ration with One Hub using
Fibre Channel Optical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–21
Units Created from Storagesets, Partitions, and Drives . . . . . . . . . . . . . . . . . . . . .3–3
A Typical Storageset Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–6
Striping Lets Several Disk Drives Participate in Each I/O Request. . . . . . . . . . . .3–9
Distribute Members across Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–11
Mirrorsets Maintain Two Copies of the Same Data. . . . . . . . . . . . . . . . . . . . . . .3–12
First Mirrorset Members on Different Buses . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–13
xii
Parity Ensures Availability; Striping Provides Good Performance. . . . . . . . . . . 3–15
Striping and Mirroring in the Same Storageset. . . . . . . . . . . . . . . . . . . . . . . . . . 3–17
CLONE Steps for Duplicating Unit Members . . . . . . . . . . . . . . . . . . . . . . . . . . 3–20
Controller Port ID and Unit Numbers in Transparent Failover Mode . . . . . . . . 3–28
Controller Port ID Numbers and Unit Numbers in Mulitple Bus Failover
Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–29
LUN Presentation Using Unit Offset on a Per-Host Basis . . . . . . . . . . . . . . . . . 3–30
Storageset Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–32
PTL Naming Convention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–34
PTL Addressing in a Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–35
Locating Devices using PTLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–36
Partitioning a Single-Disk Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–37
Chunk Size Larger than the Request Size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–48
Chunk Size Smaller than the Request Size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–49
Moving a Storageset from one Subsystem to Another . . . . . . . . . . . . . . . . . . . . 3–71
Troubleshooting: Host Canno t Acc es s Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–12
Xfer Rate Region of the Default Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–24
Regions on the Device Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–25
Unit Status on the Cache Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–29
Fibre Channel Host Status Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–32
Single Controller Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–2
Dual-Redundant Controller Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–8
Single-Battery ECB SSB Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–27
Dual-battery ECB SBB Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–27
Location of GLMs in Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–32
I/O Module Locations in a BA370 Enclosure. . . . . . . . . . . . . . . . . . . . . . . . . . . 5–39
Cache-Module Memory Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–42
Installing a DIMM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–44
Battery Disable Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–49
Location of Write-Protection Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–4
Upgrading Device Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–11
Pass-through Device Reset Event Sense Data Response Format . . . . . . . . . . . . .D–2
T emplate 01 - Last Failure Event Sense Data Response Format. . . . . . . . . . . . . .D–4
Template 04 - Mu lt ip l e -Bus Failove r Eve n t Se n se Da ta Respon se Format . . . . .D–5
xiii
Template 05 - Failover Event Sense Data Response Format . . . . . . . . . . . . . . . . D–7
Template 11 - Nonvolatile Parameter Memory Component Event Sense Data
Response Form at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D–8
Template 12 - Backup Battery Failure Event Sense Data Response Format. . . . D–9
Template 13 - Subsystem Built-In Self Test Failure Event Sense Data
Response Form at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D–11
Template 14 - Memory System Failure Event Sense Data Response Format . . D–12 Temp l at e 41 - Devi ce Servic es N o n- Tra ns f er Er ro r Event Sense Da ta
Response Form at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D–13
Template 51 - Disk Transfer Error Event Sense Data Response Format. . . . . . D–15
Structure of an Instance Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D–16
Instance Code Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D–16
Structure of a Last Failure Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D–36
Last Failure Code Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D–36

Tables

xv
Key to Figure 1–1 The HSG80 Subsystem . . . . . . . . . . . . . . . . . . .1–3
Controller Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–4
Key to Figure 1–3 HSG80 Array Controller–Fibre Channel
Copper Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–9
Key to Figure 1–4: Opti onal Maintenance Port Cable for a
T erminal Connection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–10
Key to Figure 1–4 HSG80 Array Controller–Fibre Channel
Optical cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1–11
Cache Module Memory Con f igurations. . . . . . . . . . . . . . . . . . . . . .1–18
Cache Policies and Cache Module Status . . . . . . . . . . . . . . . . . . . .1–22
Cache Policies Resulting and ECB Status . . . . . . . . . . . . . . . . . . . .1–24
ECB Capacity Based on Memory Size. . . . . . . . . . . . . . . . . . . . . . .1–29
Key to Figure 2–4 Cabling for S ingle Configur ation (copper). . . . .2–14
Key to Figure 2–5 Cabling for S ingle Configuration (optical). . . . .2–15
Key to Figure 2–6 Cabling for Dual-Redundant Conf iguration
with Two Hubs (copper) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–17
Key to Figure 2–7 Cabling for Dual-Redundant Conf iguration
with Two Hubs (optical) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–18
Key to Figure 2–8 Cabling for Dual-Redundant Conf iguration
with One Hub (copper) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–20
Key to Figure 2–9 Cabling for Dual-Redundant Conf iguration
with One Hub (optical) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2–21
Controller Limitations for RAIDsets . . . . . . . . . . . . . . . . . . . . . . . . .3–3
A Comparison of Different Kinds of Storagesets. . . . . . . . . . . . . . . .3–8
Maximum Chunk Sizes for a RAIDs et . . . . . . . . . . . . . . . . . . . . . .3–50
Unit Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3–54
Troubleshooting Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4–4
Event-Code Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4–19
FMU SET Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4–20
xvi
VTDPY Key Sequences and Commands. . . . . . . . . . . . . . . . . . . . . 4–23
Device Map Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–25
Device Status Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–26
Device-Port Status Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–28
Unit Status Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–29
Fibre Channel Hos t Status Display- Known Hosts (Connections) . 4–32
Fibre Channel Host Status Display- Port Status . . . . . . . . . . . . . . . 4–33
Fibre Channel Hos t St atus Display- Link Error Counte r s . . . . . . . 4–33
Tachyon First Digit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–35
Tachyon Second Digi t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–35
DILX Control Sequences. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–37
Data Patterns for Phase 1: Write Test . . . . . . . . . . . . . . . . . . . . . . . 4–38
DILX Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–40
Cache Module Memory Con f igurations. . . . . . . . . . . . . . . . . . . . . . 5–42
HSUTIL Messages and Inquiries . . . . . . . . . . . . . . . . . . . . . . . . . . 6–14
Cache Module Memory Con f igurations. . . . . . . . . . . . . . . . . . . . . . 6–20
Recall and Edit Command Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–4
ADD UNIT Switches for Storagesets . . . . . . . . . . . . . . . . . . . . . . .B–28
POWEROFF Switch Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–84
SET controller Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–104
EMU Set Point Temperatures. . . . . . . . . . . . . . . . . . . . . . . . . . . . .B–114
SET unit-number Switc hes for Exi sting Containers . . . . . . . . . . .B–138
Solid OCP Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C–3
Flashing OCP Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C–8
Instance Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–18
Controller Restart Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–37
Last Failure Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–38
Recommended Repair Action Codes . . . . . . . . . . . . . . . . . . . . . . .D–77
Component Identifier Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–82
Event Notification/Recovery Threshold Classifications . . . . . . . . .D–84
ASC and ASCQ Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D–85
Controller Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E–2
StorageWorks Environmental Specifications . . . . . . . . . . . . . . . . . . E–3

Preface

xvii
This book describes the features of the HSG80 array controller and configuration procedures for the controller and storagesets running Array Controller Softw are (ACS) Version 8.2G.
This book does not con tain information about the operating envi ronments to which the controller may be connected, nor does it co ntain detailed informa tion about subsystem enclosures or their components. See the documentation that accompanied these peripherals for information about them.
xviii

Precautions

Follow these precau tions when ca rr y i ng o ut th e pro cedures in th i s book.

Electrostatic Discharge Precautions

Static electricity collects on all nonconducting material, such as paper, cloth, an d plastic. An ele ctrostatic dis charge (ESD) can easily damage a controller or other subsystem component even though you may not see or feel the discharge. Follow these precautions whenever you’re servicing a subsystem or one of its components:
n
Always use an ESD wrist stra p when s ervicing the controlle r or other components in the subsystem. Make sure that the strap contacts bare skin, fits snugly, and that its grounding lead is attached to a bus that is a verified earth ground.
n
Before touching any circuit board or component, always touch a verif iable earth ground to disc harge any static electricity that may be present in you r clothing.
n
Alwa y s keep circuit boards an d component s away from nonconducting material.
n
Always keep cl othing away from circuit boards and components.
n
Always use antis tatic bags and grounding mats for storing circuit boards or component s duri ng replacement procedures.
n
Always keep the ESD cover over the program card when the card is in the controller. If you remove the card, put it in its ori ginal carrying case. Never touch the conta cts or twist or bend the card while you’re handling it.
n
Never touch the connector pins of a cable when it is attached to a component or host.

Component Precaution

System components referenced in this manual comply to regulatory standards docu mented herein. Use of other components in their place may violate country standards, negate regulatory compliance, or invalidate the warra nty on your product.

Maintenance Port Precautions

The maintenance port gen era tes, uses, and radiates radio-frequency energy through cables that are connected to it. This energy may interfere wit h radio and television reception. Do not leave a cable connected to this port when youre not communicating with the controller.
xix
xx

Conventions

This book uses th e following typogr aphical conventio ns and special notices to help you find what you’re looking for.

Typographical Conventions

Convention Meaning
ALLCAPS BOLD
ALLCAPS Command discussed within text, for exam ple:
Monospaced Screen display.
Sans seri f it a lic Command variable or numeric value that you
italic Reference to other books or publications, for
.
.
.
this controller The controller serving your current CLI session
other controller” The controller in a dual-redundant pair that’s
Command syntax that mu st be ent ered exactly as shown, for example:
SET FAILOVER COPY=OTHER_CONTROLLER
Use the SHOW SPARESET command t o show the contents of the spareset.
supply, for example: SHO W RAIDset-name or
SET THIS_CONTROLLER ID=(n,n,n,n,)
example: See the HSG80 Array Controller ACS V8.2 Release Notes for details.
Indicates that a portion of an example or figure has been omitted.
through a local or remote terminal.
connected to the cont roller serving your current CLI session.

Special Notices

xxi
This book doesn’t contain detailed desc riptions of standard safety procedures. However, it does contain warni ngs for procedures that could cause personal injury and cautions for procedures that could damage the controller or its related components . L ook for these symbols when you’re carrying out the procedures in this book:
Warning A warning indicates th e presence of a hazard that can cause personal injury if you do not observe the precautions in the text.
Caution A caution indicates the presence of a hazard that might damage hardware, corrupt software, or cause a loss of data.
Tip A tip provides alternative methods or procedures that may not be immediately obvious. A tip may also aler t cus tomers that the controller’s behavior being discussed is different from prior software or hardware versions.
Note A note provides additional information thats related to the completio n of an instruction or procedure.
xxii

Required Tools

You wil l ne ed th e f ollowing tools to se r v ic e th e contr ol l er, cache module, external cache battery (ECB), the Power Verification and Addressing (PVA) module, the Gigabit Link Module (GLM), and the I/O module:
n
A flathead screwdri v er for looseni ng and tighte ning the I/O module retaining s crews.
n
A small phillips screwdriver for loosening and tigh tening the GLM access do o r s cr ews .
n
An anti s tatic wrist strap .
n
An antistatic mat on which to place modules during servicing.
n
A Storage Building Block (SBB) Extractor for remo ving StorageWorks building blocks. This tool is not required, but it will enable you to perform more efficiently.

Related Publications

The fo ll ow in g table list s some of the do cuments th a t ar e related to th e use of the controller, cache module, and external cache battery.
xxiii
Document Title Part Number
Fibre Ch annel Ar b it r at ed Lo op H u b (DS-DHGGA-CA) Users Guide
KGPSA PCI-to-Fibre Channel Host Adapter EK–KGPSA–UG DIGITAL StorageW orks Ultra SCSI RAID
Enclosure (BA370-S eries) Users Guide The RAIDBOOKA Source for RAID
Technology DIGITAL StorageWorks HSG80 Array
Controller ACS V8.2 Release Notes
EK–DHGGA–UG
EK–BA370–UG
RAID Advisory Board
AA–RDY8A–TE
xxiv

Revision History

This is a rev ised document. Prev ious documents include:
EK-HSG80-UG .A01 ACS Version 8.0 January 1998

CHAPTER 1

General Description

This chapter i llustrates and describes in general terms your subsystem and its major components: the HSG80 array controller, its cache module, and its external cache battery. See the Fibre Channel Arbitrated Loop Hub User’s Guide and the KGPSA PCI-to-Fibre Channel Hos t Adapter User Guide for information about the fibre channel arbitrated loop hub and adapter that connect the subsystem to your host.
1–1
12 HSG80 Users Gui de

The HSG80 Array Controller Subsystem

Take a few moments to familiarize yourself with the major components of the HSG80 Array Controlle r subsys tem. Figure 1–1 shows the components of a typical installation which includes:
n
One BA370 rack-mountable pedestal enclosure.
n
Two controllers, each supported by their own cache module.
n
T wo ex ternal cache bat ter ies (ECBs ) in one Stora ge Build ing Bl ock (SBB), which provide backup power to the cache modules during a primary powe r failure.
n
One environmental monitoring unit (EMU) that monitors the subsystem’s environment, and alerts the controller of equipment failures that could cause an abnormal environment.
n
One power verification and addressing (PVA) module that provides a unique address to each enclosure in an ex tended subsystem.
n
Six I/O modules that in tegrate the SSB shelf with either an 8-bit single-ended, 16-bit single-ende d, or 16-bit differ ential SCSI bus.
n
Two cache modules, which support non volatile memory and dynamic cache policies to protect the availability of its unwritten (write-back) data.

Figure 1–1 The HSG80 Subsystem

12
11
4x
10
9
8
7
General Descrip ti on 1–3
1
2
3
6x
6
5
4
CXO6453A
Table 1–1 Key to Figure 1–1 The HSG80 Subsystem
Item Description Part No.
1 BA370 rack-mountable enclosure DS–BA370–AA 2 Cooling fan DS–BA35X–MK 3 I/O module 70–32876–01 4 AC input module DS–BA35X–HE 5 PVA module DS–BA35X–EC 6 Cache module B 70–33256–01 7 Cache module A 70–33256–01 8 HSG80 controller B 70–33259–01 9 HSG80 controller A 70–33259–01
10 EMU 70–32866–01
1–4 HSG80 Users Gui de
Table 1–1 Key t o Fig u re 1–1 The HSG80 Subsystem (Continued)
Item Descripti on Part No.
11 180-watt power supply DS–BA35X–HH 12 ECB, single

Summary of HSG80 Features

Ta ble 1–2 summarize s the featu r es of the controller.
Table 1–2 Controller Features
Controller Failover
Topology
Supported Operating Systems
Host protocol Host bus interconnect
ECB, dual
Feature Supported
n
Transparen t Failov er
n
Multiple Bus Failover
n
FC–AL
n
8 nodes per loop; maxi mum 4 initiators per loop
n
single and dual host adapter(s)
n
2 controller subsystems; maximum 4 controllers (2 dual-redundant configurations)
n
128 LUNs in Transparent and Multiple Bus F ailover Mode
n
WINNT/Intel
n
WINNT/Alpha
n
FC–AL
n
Copper Optical : MultiMode 50 Micron (Do not mix media types)
DS–HS35X–BC DS–HS35X–BD
n
Gigabit link module (GLM)
General Descrip ti on 1–5
Table 1–2 Controller Features (Continued)
Feature Supported
n
Device protocol
Device bus interconnect
SCSI–2
n
Limited SCSI–3
n
Ultra/Fast Wide Sin g le­ended
n
Number of SCSI device ports Number of SCSI device tar gets per
6
n
12
port
n
Maximum number of SCSI
72
devices
n
Disk Drives
4 and 9 GB Ultra & Fast Wide
n
18 GB Ultra
n
4 GB 10K Ultra
n
RAID levels supported
0
n
1
Cache C ap acity
Caching Feature s
Maximum number of RAID-5 and RAID-1 storagesets
Maximum number of RAID-5 storagesets
n
0+1
n
3/5
n
64 MB and 128 MB (32 MB DIMMs only)
n
256 MB and 512 MB (128 MB DIMMs only)
n
Mirrored Cache
n
Sequential Read Ahead
n
Graceful Power Down Policy
n
UPS support with “auto cache flus h
n
30
n
20
1–6 HSG80 Users Gui de
Table 1–2 Controller Features (Continued)
Feature Supported
n
Maximum number of RAID-5,
45
RAID-1, and RAID-0 storagesets
n
Maximum number of partiti ons
8
per storageset or individual disk
n
Maximum number of units presented to each host
Maximum number of devices per
16 (8 on each of 2 ports) This is a driver li m i t ation.
n
48
unit
n
Serial interconnect speed Maximum device, storageset, or
1 GB/second
n
512 GB LUN capacity
unit size
n
Configuration Save
Transfer configuration from HSZ70 subsyste m to HSG80 controller
n
Transfer configuration from ACS V 8.0 to ACS V 8.2
n
General Features
Host Modes/Access Privileges
n
Persistent Reserve s
n
Program card updates
n
Device warm swap
n
Utiliti es to test disks

The HSG80 Array Controller

Your controller is the intelli gent bridge between your host and the devices in your subsystem. As Figure 1–2 illustrates, it bridges the gap between the host and its storage subsystem.

Figure 1–2 A Host and Its Storage Subsystem

Host
General Descrip ti on 1–7
Storage subsystem
Hub
Controller
CXO6233B
The controller is an integral part of an y st orage subsystem because it provide s a host with high-performance and high-avail ability access to storage devices.
The contro ller provides the ability to comb ine several ordinary disk drives into a sin g le , h ig h - pe r f o rm an c e en ti t y ca ll ed a s to rag eset. Storagesets are implementations of RAID technology, which ensures that every unpartitioned storageset, whether it uses tw o disk drives or ten, looks li ke a single storage unit to the host. See Chapter 3, Creating Storagesets, for more information about storagesets and how to configure them.
From the host’s perspective, the controller is simply another device connected to one of its I/O buses. Consequent ly, the host sends its I/O requests to the controller just as it would to any Fibre Channel devi ce. From the subsyst em’s perspecti ve, the controller receives the I/O requests and directs them to the devices in the subsystem. Because the
1–8 HSG80 Users Gui de
controller proc es ses the I/O requests, the host isnt burdened by the processing thats typically associated with rea ding and writing data to multiple storage devices.
For the most r ecent list of support ed devices and oper ating systems, see the product-specific release note s that accompanied your controller’s software. To determine which specific parts you nee d for your config uration, see Connecting the Subsystem to the Host, page 2–14.
Figure 1–3 and Figure 1–4 detail the HSG80 Array Controller and its fibre channel components. Figure 1–5 highlights th e variant par ts for an optical configuration.

Figure 1–3 HSG80 Array Controller Fibre Channel Copper Cabling

2
1
3x
1 2 3 4 5 6
11
2x
12
10
3
2x
4
5
6
7
2x
8
9
To terminal
CXO6467A
General Descrip ti on 1–9
Table 1–3 Key t o Fig u re 1–3 HSG80 Array Controller–Fibre
Channel Copper Cabling
Item Description Part No.
1 Backplane connectors 2 Access Door 70–33287–01 3GLM 30–49226–01 4 Program-card slot 5 Program-card ejection button 6 Program card BG–R8Q3B–BA 7 ESD/PCMCIA card cov er 74–52628–01 8 5-meter Fibre Channel copper cable
10-meter Fibre Channel copper cable
9 Maintenance Port Cable
n
See Figure 1–4 for information
17–04718–06 17–04718–07
17–04074–02
on an optional maintenance port
cable and its parts 10 Maintenance Port 11 Operator control panel (OCP ) 12 Lever for removing, installing, and
retaining cont roller module.
1–10 HSG80 Users Guide
Figure 1–4 Optional Maintenance Port Cable for a Terminal
Connection
1
2
3
4
5
CXO6485A
Table 1–4Key to Figure 1–4: Optional Maintenance Port Cable for
a Terminal Connection
Item Description Part Numb er
1 BC16E-xx Cable Assembly 17–04074–01 2 Ferrite Bead 16–25105–14 3 RJ-11 Adapter 12–43346–01 4 RJ-11 Extension Cable 17–03511–01 5 PC Serial Port Adapter, 9 pin
12–45238–01
D-sub to 25 pin SKT D-sub for a PC
PC Serial Port Adapter, 9 pin D-sub to
12–45238–02
25 pin D-sub for Sun operating system
PC Serial Port Adapter, 9 pin D-sub to
12–45238–03 25 pin D-sub, mod for an HP800 operating system

Figure 1–5 HSG80 Array Controller–Fibre Channel Optical Cabling

1
2x
1 2 3 4 5 6
Table 1–5 Key t o Fig u re 1–4 HSG80 Array Controller–Fibre
Channel Optical cabling
Item Descri ption Part No .
1GLM 30–50124–01
General Descrip ti on 1–11
2x
2
CXO6494A
2 2 M Fibre Channel opti cal cable
5 M Fibre Channel optical cable 10 M Fibre Channel optical cable 20 M Fibre Channel optical cable 30 M Fibre Channel optical cable 50 M Fibre Channel optical cable
17–04820–03 17–04820–05 17–04820–06 17–04820–07 17–04820–08 17–04820–09
Caution If the Fibre Channel optical cable is not properly connec ted to the controller, controlle r f ailure may result. In addition, if the cable is not regularly maintained, its perf orm ance and lifespan will be affected. Before proceeding, it is important to administer the precationa ry measures detailed in the following secti ons.
Fibre Channel Optical Cable Precautions
Prior to connecting the Fibre Channel cable to the controller , look for the white stripe on each side of the coupling. After the cabl e is seated into th e co ntroller, be su re that the white strip es are hidden . Also, whe n connecting the Fibre Channel cable to the controller, listen for a
1–12 HSG80 Users Guide
1. Open the prep cleaner using the lever on the side of the cable cartridge.
2. Rotate the end f ace of the ferrule 180 degrees.
3. Slide the ferrule end face along the opening to one si de of the coupling.
4. Insert a lint-free polyester swab to dust out the cavity.
5. Remove the lint- fr ee pol yset er s w ab, a nd re turn the f err ule t o it s or igina l
6. Repeat 180 de gree rotation in the opposite direction.
7. Slide the ferrule end face along the opening to the oppos ite side.
8. Insert the lint-free polyester swab to dust out the cavity.
distinctive “snap” sound. This will indicate that the cable is properly insert ed into the controller.
Fibre Channel Optical Cable Cleaning Instructions
It is essential to maintain clean cables to ensure optimum performance and lifespan of the cable. Figure 1–6 illustrates the proper clean ing procedures , as outlined in the follo w ing steps:
position.
9. Return to step 5, and re peat remaining procedures until all areas of the cartr i dge are cleaned.
Note Be sure to clean both cartridges of the fibre ch annel coupling.

Figure 1–6 Fibre Channel Optical Cleaning Procedures

Small diameter lint-free polyester swab
Ferrule
CXO6503A
General Descrip ti on 1–13
The HSG80 Array Controller components that you will use most ofte n, such as the maintenance port and the OCP, are conveniently located on the cont r oller’s front panel. The host port and program-card slot are also located on the front panel, ma king it easy to update the controller’s software or to connect the controller to a different host.
Each controller is supported by its own cache module. Figure 1–4 shows which cache module supports which controller in a dual­redundant configuration in a BA370 rack-mountable enclosure.
Figure 1–7 Location of Controllers and Cache Modules
Tip D IGITAL recommends that you use the slots for controller A and
cache module A for single configurations. Slot A responds to SCSI target ID number 7 on device buses; slot B responds to SCSI target ID number 6 on the device buses.

Operator Control Pane l

The operator control panel (OCP) contains a reset button and six port LED but to ns, as sh own in Fi gu r e 1–5. The reset button flashes about once per second to indi cate that the controll er is operating normally. The port button LEDs correspond to the controllers device ports and remain off during normal operation. If an error occurs, the reset b utton and LEDs will illuminate in a solid or flashing pat tern to help you diagnose the problem. See Appendix C, LED Codes,” for further explanation on these codes.
EMU
Controller A Controller B
Cache module A Cache module B
PVA
CXO6283A
1–14 HSG80 Users Guide
Figure 1–8 HSG80 Controller Operator Control Panel (OCP)

Maintenance Port

Reset button/ LED
123456
Port button/ LED
CXO6216A
To identify the exact lo cation of the OCP, refer to Figu r e 1 –3.
Under normal circumstances, you will not need to remove the controller from its enclosure. For thi s reason, the components that you will use most often are conveniently located on the front pan el. For example, the maintenance port provides a convenient way to connect a PC or terminal to your controller so that you can interact with it.
After you configure your controller, you should per iodically check its control panel. If an error occ urs, one or more of the LEDs on the control panel will flash in a pattern that will help you to diagnose the problem. See Chapter 4, “Troubleshooting,for details about troubleshooting your controller.
You can access the controller through a PC or a local terminal via the maintenance port, or through a remote terminalsometimes called a virtual terminal or host consolevia the host. D I G ITAL recomm en d s that you use a PC or a local term inal to carry out the troubles hooting and servicing proc edures in this manual. See Establishing a Local Connection to the Controller, page 2–7, for more information on connecting the controller with a mainte nance port cable.

Utilities and Exercisers

The controller ’s software includes the following utilities and e xercisers to assist in tro ubleshooting and maintaining the controller and the other modules that support its operation:
General Descrip ti on 1–15
Fault Management Utility
The Fault Managem ent Utility (FMU) provides a limited interface to the cont r oller’s fault-management system. As a troubleshooting tool, you can use FMU to display last-failure and memory-system-failure entries, translate many of the code values contained in event messages, and set the dis p lay charact eristics of significant events and failures.
See Fault Manageme nt Utility, page 4–17, for more information about using thi s utility.
Virtual Terminal Disp l ay
Use the virtual terminal display (VTDPY) utility to troubleshoot communicati on between the controller and its host, communicati on between the controller and the device s in the subsystem, and the state and I/O activity of the logical units, devices, and device ports in the subsystem.
See Using VTDPY to Check for Communication Problems, page 4–23, for more information about using this utility.
Disk Inline Exerciser
Use the disk inline exer ciser (DILX) to invest igate the data-transfer capabilities of disk drives. DILX tests and verifies operation of the contr o ller and the S C SI–2 disk drives attached to it. DILX generate s intense read and write loads to th e d i sk drive while monitoring the drive’s performance and status. See “Checking for Disk-Dr ive Problems,” page 4–37, for more information about this exerciser.
Configuration Utility
Use the configuration (CONFIG) utility to ad d one or mor e storage device s to the subsystem. This utili ty checks the device ports for new disk drives then adds them to the controllers c onfiguration and automatically names them. See “Adding Several Disk Drives at a Time, pa g e 3–55, for more information about using the CONFIG utility.
1–16 HSG80 Users Guide
HSUTIL
Use HSUTIL to upgrade the firmware on disk drives in the subsystem and to format disk drives. See Upgrading Firmware on a Device, page 6–11, for more information about this utility.
Code Load and Code Patch Utility
Use Code Load/Code P atch (CLCP) utility to upgrade the controller software and the EMU software. You can also use it to patch the controller software. When you install a new controller, you must have the correct software version and patch number. See “Upgrading Controller Software, page 6–2, for more information about using this utility.
Note Only DIGITAL field service personnel are authorized to upload EMU microcode updat es . Contact the Customer Service Center (CSC) for directions in obtaining the appropriate EMU micro code and installa tion guide.
Clone Utility
Use the Clone utility to duplicate th e data on any unpartitioned single­disk unit, stripeset, or mirrorset. Bac k up the cloned data while the actual storageset remains online. See Cloning Data for Backup, page 3–19, for more information about using the Clone utility.
Field Replacement Utility
Use the field replacement utility (FRUTIL) to replace a failed controller (in a dual-redundant configuration) without shutting do wn the subsystem.You can also use this menu-driven utility to replace cache modules and ext ernal cache batteri es . See Chapter 5, “Replacement Procedures, for a more detailed explanation of how to use FRUTIL.
General Descrip ti on 1–17
Change Volume Serial Number Utility
Only DIGITIAL authorized service personnel may use this utility.
The Change Volume Serial Number (CHVSN) utility generates a new volume serial number (call ed VSN) for the spec ified device and writes it on the media. It is a way to eliminate duplicate volume serial numbers and to rename duplic ates with different volume serial numbers .
Device Statistics Utilit y
The Device Statistics (DST AT) utility allows you to log I/O activity o n a controlle r over an e xtended period of time. Later, you can anal yze that log to determi ne where the bottlenecks are a nd h ow to tune the controller for optim um perform ance.
1–18 HSG80 Users Guide

Cache Module

Each controlle r requires a companion cache module as shown in Figure 1–9. Figure 1–7 on page 1–13 shows the loca tion of a controller’s companion cache module. The cache module, whic h can contain up to 512 MB of memory, increases the subsystem’s I/O performance by providi ng r ea d, read-ahead, write-th rough, and write-back caching.
The size of the memory cont ained in the cache module depends on the configuration of the DIMMs, with the supported combinations shown in Table 1–6. For placement of the DIMMs, see “Replacing DIMMs,” page 5–42.

Table 1–6 Cache Module Memory Configurations

DIMMs Quantity Memory
32 MB 2 64 MB 32 MB 4 128 MB 128 MB 2 256 MB 128 MB 4 512 MB
General Descrip ti on 1–19

Figure 1–9 Cac he Module

5
4
3
2x
Item Description Part No.
1 Cache-memory power LED button
1
~
2
CXO6161A
2 ECB Y cable for the BA370
17–04479–03
Enclosure
ECB Y cable for the Data Center
17–04479–04
Cabinet 3 Retaining lever 4 Backplane co n nector 5 64 MB cache upgrade
256 MB cache upgrade
DS-HSDIM-AB
DS-MSDIM-AC
1–20 HSG80 Users Guide

Caching Techniques

The cache module sup ports the following caching techniques to increase the subsystem’s read and write performance:
n
Read cach i ng
n
Read-ahead caching
n
Write-through ca ch ing
n
Write-back caching
Read Caching
When the controller receives a read req uest from the host, it reads the data from the disk drives, delivers it to the hos t, and stores the data in its cache module. This process is called read caching.
Read caching can decrease the subsystems response time to many of the host’s read requests. If the host requests some or all of the cached data, the controller satisfi es the request from its cache module rather than from the disk drives. By default, read caching is enabled for all storage units.
See SET unit number MAXIMUM_CACHED_TRANSFER in Appendix B, CLI Commands, for more details.
Read-Ahead Caching
Read-ahead caching begins when the co ntroller has already processed a read request, and it receives a sequential read reques t from the host. If the controller does not find the data in the cache memory, it reads the data from the disks and sends it to the cache memory.
The controller then anticipates subse quent read requests and begins to prefetch the next blocks of data from the disks as it sends the requested read data to the host. This is a parallel action. The controller notifies the host of the read completion, and subsequent sequential read requests are satisfied f rom the cach e memory. By default, read- ahead caching is enabled for all disk units.
General Descrip ti on 1–21
Write-Through Caching
When the contr oller receives a write request from the host, it stores the data in its cache module, writes the data to the d isk drive s, then notifies the hos t when th e w r it e o peration is co m p l ete. This pr o c ess is calle d write-thr ough ca ching because the data actually passes throughand is stored inthe cache memory on its way to the disk drives.
If you enable read caching for a storage unit, write-through caching is automatically enabled. Likewise, if you disable rea d caching, write­through caching is automatically disabled.
Write-Back Caching
This caching te chnique improves the subsystem’s response time to write r eq u est s by a ll owin g th e co n tr o l le r to de cl a re th e w r it e op e r at io n complete as soon as the data rea ches its cache memory. The controller performs the slower operation of writing the data to the dis k drives at a la ter time.
By default, write-back caching is enabled for all units. In either case, the controller will not provide write- back caching to a unit unless the cache memory is non-volatile, as described in the next section.

Fault-Tol erance for Write-Back Caching

The cache module supports nonvol atile memory and dynamic cache policies to protect the availability of its unwritten (write-back) data:
Nonvolatil e Memory
The controller can provide write-back caching for any storage unit as long as the controllers cac h e memory is nonvolatile . I n other words, to enable write-back caching, you must provide a backup power source to the cac he mo du l e to pr e s er ve th e unw r i tt en cache data in th e even t of a power failure. If the cache memory were volatil ethat is, if it didn’t have a backup power supplythe unwritte n ca che data would be lost during a power fa ilure.
By default, the controller expe cts to use an ECB as the backup power source for its cache module. See External Cache Battery, page 1–28, for more information about the ECB. However, if your subsystem is backed up by a UPS (uninterruptible power supply), you can tell the controller to use the UPS as the backup power source with the SET
1–22 HSG80 Users Guide
THIS CONTROLLER CACHE_UP S command. See Appendix B, “CLI Commands,” for instructions on using this command.
Cache Policies Resulting from Cache Module Failures
If the co ntroller detects a fu l l o r p ar t ial failu re of it s c ac he modul e o r ECB, it automatically reacts to preserve the unwritten data in its cache module. Depending upon the severity of the failure, the controller chooses an interim caching technique (als o called the cache policy) which it uses until you repair or replace the cache mo dule or ECB.
Table 1-7 sho w s the cache policies result ing from a full or partial failure of cache module A in a dual-redundant controller configur ation. The consequences shown in this table are the same for cache module B.
Table 1-7 Cache Policies and Cache Module Status
Cache Module Status Cache Policy
Cache A Cache B U nmirrore d Cache Mirrored Cache
Good Good Data loss: No
Cache policy: Both controllers
support write-back caching. Failover: No
Multibit cache memory failure
Good Data loss: Forc ed error and los s of
write-back data for which multibit error occurred. Controller A detects and repo rts the lost blocks.
Cache policy: Both controllers support write-back caching.
Failover: No
Data loss: No Cache policy: Both controllers
support write-back caching.
Failover: No
Data loss: No. Controller A
recovers its lost wr ite-back data from the m irr o r ed copy on ca ch e B .
Cache policy: Both controllers support write-back caching.
Failover: No
General Descrip ti on 1–23
Table 1-7 Cache Policies and Cache Module Status (Continued)
Cache Module Status Cache Policy
Cache A Cache B U nmirrore d Cache Mirrored Cache
DIMM or cache memory controller chip failure
Good Data integrity: Write-back data
that was not writt en to media when failure occurred was not recovered.
Cache policy: Controller A supports writ e-through caching only; contr oller B supports write­back cach i n g.
Failover: In transparent failover, all units failover to controller B. In multiple-bus failover with host­assist, only those units that us e write-back caching, such as RAIDsets and mirrorsets, failover to controller B. All units with lost data become inoperative until you clear them with the CLEAR LOST_DATA command. Units that di d nt lose data operate normally on controller B.
In single contr oll er conf igur ati ons, RAIDsets, mirrorse ts, an d all uni ts with lost dat a be come inoperative. Although you can clear the lost data errors on some units, RAIDsets and mirrorsets remain inoperative until you repair or replace t he nonvolati le m emory on cache A.
Data integrity: Controller A recovers all of its write-back data from the m irr o r ed copy on ca ch e B .
Cache policy: Controller A supports writ e-through caching only; contr oller B supports write­back cach i n g.
Failover: In transparent failover, all units failover to con tr oller B and operate normally. In multiple-bus failover with host-assist, only those units that use write-back caching, such as RAIDsets and mirrorsets, failover to controller B.
1–24 HSG80 Users Guide
Table 1-7 Cache Policies and Cache Module Status (Continued)
Cache Module Status Cache Policy
Cache A Cache B U nmirrore d Cache Mirrored Cache
Cache Board Failure
Good Same as for DIMM failure. Data integrity: Controller A
recovers all of its write-back data from the m irr o r ed copy on ca ch e B .
Cache policy: Both controllers support write-t hrough caching only. Controlle r B cannot execute mirrored writes because cache module A cannot mirror controller Bs unwritten data.
Failover: No
Table 1-8 sho ws the cache policies result ing from full or partial failure of cache module A’s ECB in a dual-redundant configuration. Note that when cache module A is at least 50% charged, the ECB is still operable and charging. When it is less than 50% charged, the ECB is low but still charging. The consequences shown in this table are reciproca l for a failure of cache module Bs ECB.
Table 1-8 Cache Policies Resulting and ECB Status
Cache Mo dule St atus Cach e Policy
Cache A Cache B Unmirrored Cache Mirrored Cache
At leas t 50% charged
At leas t 50% charged
Data loss: No Cache policy: Both controllers
continue to support write-back caching.
Failover: No
Data loss: No Cache policy: Both controllers
continue to support write-back caching.
Failover: No
General Descrip ti on 1–25
Table 1-8 Cache Policies Resulting and ECB Status (Continued)
Cache Mo dule St atus Cach e Policy
Cache A Cache B Unmirrored Cache Mirrored Cache
Less than 50% charged
At leas t 50% charged
Data loss: No Cache policy: Controller A
supports writ e-through caching only; contr oller B supports write­back cach i n g.
Failover: In transparent failover, all unit s fai lo ver to contro ller B.
In multipl e-bus failover with host ­assist, only those units that us e write-back caching, such as RAIDsets and mirrorsets, failover to controller B.
In single configurations, the controller only provides write­through caching to its units.
Data loss: No Cache policy: Both controllers
continue to support write-back caching.
Failover: No
1–26 HSG80 Users Guide
Table 1-8 Cache Policies Resulting and ECB Status (Continued)
Cache Mo dule St atus Cach e Policy
Cache A Cache B Unmirrored Cache Mirrored Cache
Failed At least
50% charged
Less than 50% charged
Less than 50% charged
Data loss: No Cache policy: Controller A
supports writ e-through caching only; contr oller B supports write­back cach i n g.
Failover: In transparent failover, all unit s fai lo ver to contro ller B and operate normally.
In multipl e-bus failover with host ­assist, only those units that us e write-back caching, such as RAIDsets and mirrorsets, failover to controller B.
In single configurations, the controller only provides write­through caching to its units.
Data loss: No Cache policy: Both controllers
support write-through caching only.
Failover: No
Data loss: No Cache policy: Both controllers
continue to support write-back caching.
Failover: No
Data loss: No Cache policy: Both controllers
support write-through caching only. Failover: No
General Descrip ti on 1–27
Table 1-8 Cache Policies Resulting and ECB Status (Continued)
Cache Mo dule St atus Cach e Policy
Cache A Cache B Unmirrored Cache Mirrored Cache
Failed Less
Data loss: No
than 50% charged
Cache policy: Both controllers support write-through caching only.
Failover: In transparent failover, all unit s fai lo ver to contro ller B and operate normally.
In multipl e-bus failover with host ­assist, only those units that us e write-back caching, such as RAIDsets and mirrorsets, failover to controller B.
In single configurations, the controller only provides write­through caching to its units.
Failed Failed Data loss: No
Cache policy: Both controllers support write-through caching only.
Failover: No. RAIDsets and mirrorsets become inoperative. Other units that us e write-back caching o pe rat e w it h wri te ­through caching only.
Data loss: No Cache policy: Both controllers
support write-through caching only.
Failover: No
Data loss: No Cache policy: Both controllers
support write-through caching only. Failover: No. RAIDsets and
mirro r sets become inoperative. Other units that us e write-back caching operate with write-through caching o nly.
1–28 HSG80 Users Guide

External Cache Battery

To pres er ve the wr i te - b ac k cache data in th e even t o f a p r imary power failure, a cache module must be connected to an external cache battery (ECB) or a UPS.
DIGITAL supplies two versions of ECBs: a singl e-battery ECB for single cont roller configurations, and a dual-batt ery ECB for dual­redundant cont roller configurations, which is shown in Figure 1–10.

Figure 1–10ECB for Dual-Redundant Configurations

1
SHUT OFF STATUS
2
POWER
CACHE POWER
STATUS SHUT OFF
4
CACHE
3
~
CXO5713A
Item Description Part No.
Dual battery E CB SB B (St orage
DS–HS35X–BD
Building Block)
Single bat tery ECB SBB DS–HS35X–BC 1 Shut off button 2 Status LED 3 ECB Y cable for the BA370 Enclosure
ECB Y cable for the Data Center
17–04479–03
17–04479–04
Cabinet 4 Micro-D port for second batte ry

Charging Diagnostics

General Descrip ti on 1–29
When the batteries are fully charged, an ECB can preserve 512 MB of cache memory for 24 hours. However , the battery capacity dep ends upon the size of memory contained in the cache module, as defined in the Table 1–9.
Table 1–9 E CB Capacity Based on Memory Size
Size DIMM Combinations Capacity
64 MB Two, 32 MB 96 hours 128 MB Four, 32 MB 48 hours 256 MB Two, 128 MB 48 hours 512 MB Four, 128 MB 24 hours
Whenever you restart the controller, its diagnostic routines automatically check the charge in the ECB’s batteries. If the batteries are fully charged, the controller reports them as good and rechecks them every 24 hours. If the batteries ar e cha rging, the control ler rechecks them every fo u r minutes. Batteries are reported as being eithe r above or bel ow 50 percent in capacity. Batteries below 50 percent in capacity are ref erred to as being low.
This four-minute polling conti nues for up to 10 hoursthe maximum time it should take to recharge the batteries. If the batteries have not been charged s ufficiently after 10 hours, the controller declares them to be failed.
Battery Hysteresis
When charging a battery, write-back caching wil l be al lowed as long as a previous down time has not drained more than 50 percent of a battery’s capacity. When a battery is operating below 50 percent capacity, the batter y is considered to be low and write-back caching is disabled.
Caution DIGITAL recommends that you replace the ECB every two years to prevent battery failure.
1–30 HSG80 Users Guide
Note If a UPS is used for backup power, the controller does not check the battery. See Appendix B, CLI Commands, for information about the CACHE_UPS and NOCACHE_UPS swit che s .

CHAPTER 2

Configuring an HSG80 Array Controller

This chapter explains how to configure an HSG80 Array Controller and the modules that support its operation in a StorageWorks subsystem.
2–1
2–2 HSG80 User’s Guide

Introduction

Configuration Rules

Use the Getting Started Guide that came with your subsystem to unpack and set up your subsystem prior to configuring your controller. Unless you specifically request ed a preconfigured subsys tem, you will have to configure your controller and its subsystem before you can use them.
For the complete syntax and descriptions of the CLI commands used in the configuration procedure, see Appe ndix B, CLI Commands.
Before you configure your controller, review these configuration rules and ensure your planne d configuration meets the requirements and conditions.
n
Maximum 128 visible LUNs/200 assignable unit numbers
n
Maximum 512 GB LUN capacity
n
Maximum 72 physical devices
n
Maximum 20 RAID-5 storagesets
n
Maximum 30 RAID-5 and RAID-1 storagesets
n
Maximum 45 RAID-5, RAID-1, and RAID-0 storages ets
n
Maximum 8 partitions of a storageset or individual disk
n
Maximum 6 members per mirrorset
n
Maximum 14 members p er RAID-5 storage set
n
Maximum 24 members p er Stripese t
n
Maximum 48 physical devices per striped mirrorset
Configuring an HSG80 Array Controller 2–3

Configuring an HSG80 Array Controller

You can use this procedure to configure your controller in one of the follo wing ways:
n
Single controller
n
Dual controllers (in transparent failover mode)
n
Multiple-bus failover (host-assisted), dual-redundant controllers
References sited in the steps below will help you locate detai ls about the comm an ds and conc epts.
Use the fo llowing steps to configure an HS G 8 0 ar ray controller:
1. Use the power verification and addressing (PVA) module ID switch to set the SCSI ID number for the BA 370 rack-mountable enclosure.
See Setting the PVA Module ID Switch, page 2–6, for details about PVA switc h settings.
2. Remove the program card ESD cover, and insert the controller’s program card. Replace the ESD cover.
3. Turn on the power to the pedestal enclosure.
4. Establish a local connection to the controller. See Establishi ng a Lo cal Connection to the Controller, page 2–7, for
details about creating a local conne ction.
5. Choose a config uration fo r the controller:
a. If you are configuring dual- redundant controllers in
transpare nt failover mode, proceed to step 9.
b. If you are configuring dua l-redundant control lers in multiple-
bus (so metim es c a lled hos t - a ssisted) fail over mod e, skip t o step 10.
6. If the controller reports a node ID of all zeros (0000-0000-0000-0000) set the subsystem worldwide name (node ID) to the worldwide name that came with your subsystem. Use the steps in Restoring Worldwide Names (Node IDs), pa g e 3 –26.
7. Set the port topology for each port.
SET THIS_CONTROLLER PORT_1_TOPOLOGY=topology SET THIS_CONTROLLER PORT_2_TOPOLOGY=
topology
2–4 HSG80 User’s Guide
8. If you selected LOOP_HARD for the port topology, specify the
9. Put this controller” into transparent failover mode. Use the f ollowing
If this is a single configuration with a single hub, set PORT 2 off-line.
If this is a dual-redundant configuration, the other controller inherits this controller’s port topology.
See Appendix B, CLI Commands, for more information about using the SET THIS_CONTROLLER PORT_n_TOPOLOGY= command.
arbitrated loop physical address (ALPA) for the host ports.
SET THIS_CONTROLLER PORT_1_ALPA=address SET THIS_CONTROLLER PORT_2_ALPA=address
If this is a dual-redundant configuration, the other controller inherits this controller’s” port ALPA addresses.
See Appendix B, CLI Commands, for more information about using the SET OTHER_CON T ROLL ER PO RT_n_ALPA= command.
syntax:
SET FAILOVER COPY = THIS_CONTROLLER
The other controller inheri ts this controller’s configuration, then restarts. Wait for it to return to normal operation before continuing.
See details abou t failover modes in Select in g a Failover Mode, page 2–10.
10. Put this controller in multiple-bus failover mode using the follwing syntax:
SET MULTIBUS_FAILOVER COPY=THIS_CONTROLLER
The other controller inheri ts this controller’s configuration, then restarts. Wait for it to return to normal operation before continuing.
See Selecting a Failover Mode, page 2–10 , f or details about failove r modes.
11. Optional: Change the CLI prompt. Type the following command:
SET THIS_CONTROLLER PROMPT = new prompt
Configuring an HSG80 Array Controller 2–5
If youre c onfiguring dual-redundant controlle r s , also change the CLI prompt on the other controlle r. Use the following syntax:
SET OT HER_ CO NT ROL LER PRO MP T = new prompt
See Appendix B, CLI Commands, for more information about using the SET OTHER_CONTROLLER PROMPT= command.
12. Optional: Indicate that your subsys tem power is supported by a UPS. Use the following syntax:
SET THIS_CONTROLLER CACHE_UPS
The other controller inheri ts this controller’s cache UPS setting. See Backing up Power with a UPS, page 2–13, for more information.
13. Restart the controller, using the following syntax:
RESTART THIS_CONTROLLER
If this is a dual-redundant configuration, restart the “other controller using the following syntax:
RESTART OTHER_CONTROLLER
See the RESTART THIS_CONTROLLER command in Appendix B, CLI Commands, for more information about using this command.
14. When the CLI prompt reappears, it will display details about the controller you configured. Use the following syntax:
SHOW THIS_CONTROLLER FULL
See the SHOW THIS_CONTROLLER FULL command in Appendix B, CLI Commands, for more information about using this command.
15. Connect the controller to the host.
See Connecting the Sub system to the Host, page 2–14 for information about how to complete the connection.
16. Plan and configure storages ets for your subsystem.
See Chapter 3, Creating Storagesets, for detailed information about planning and configuring storagesets.
Note If you have probl ems during the configuration, use the SET NOF AILOVER and CONFIGURATION RESTORE commands to reset the system to the factory settings. You must reset the controller after these co mmands ar e en t er ed to employ th e origina l settings .
2–6 HSG80 User’s Guide

Setting the PVA Module ID Switch

The Power, Verification, and Addressing (PVA) module provides unique addresses to extended subsystems. Each BA370 rack-mountable enclosure in an extended subsystem must ha ve its own PVA ID. Use PVA ID 0 for the enclosure that c ontains the array controllers. Use PVA IDs 2 and 3 for the additional enc los ures. Figure 2–1 illustrates the PVA settings in an extended subs ystem.
See the documenta tion that accompanied your enc losure for more details about the PVA and its settings.
Figure 2–1 SCSI Target ID Numbers on the Controller Device Bus and PVA Settings in an
Extended Subsytem
First Expansion
Enclosure
SCSI Target ID = 11
SCSI Target ID = 10
SCSI Target ID = 9
SCSI Target ID = 8
EMU
OTE: SCSI target IDs 4 and 5 are reserved. IDs 6 and 7 are used by the controllers.
PVA 2
Master
Enclosure
SCSI Target ID = 3
SCSI Target ID = 2
SCSI Target ID = 1
SCSI Target ID = 0
EMU
Controller A Controller B
PVA 0
Cache B Cache A
Second Expansion
SCSI Target ID = 15
SCSI Target ID = 14
SCSI Target ID = 13
SCSI Target ID = 12
Enclosure
EMU
PVA 3
CXO5806B
Configuring an HSG80 Array Controller 2–7

Establishing a Local Connection to the Controller

You can communicate with a controller locally or remotely. Use a local connection to configure the controller for the first time. Use a remote connection to your host system for all subseque nt configuration tasks. See the Getting Started Guide that came with your platfo rm kit for details.
The maintenan ce po rt provides a convenient way to connect a PC or terminal to the controller so that you can troubleshoot and conf igure it. This port acc epts a standard RS-232 jack from any EIA-423 compatible terminal or a PC with a terminal-emulation program. The maintenance port supports ser ial communications with default value s of 9600 baud using 8 data bit s, 1 stop bit, and no parity.
Note The maintenance port cable shown in Figure 2–2 has a 9-pin connector molded onto its end for a PC connection. If you need a terminal conne ction, see Figure 1–4 on page 1–10 for information on optional cabling.

Figure 2–2 Terminal to Local-Connection Port Connection

1 2 3 4 5 6
Maintenance port
Maintenance port cable
CXO6476A
2–8 HSG80 User’s Guide
1. Turn off the PC or terminal, and connect it to the controller, as shown i n
2. Turn on the PC or terminal.
3. Configure the terminal for 9600 baud, 8 dat a bits, 1 stop bit, and no
Caution The local-connection port described in this book generates, uses, and can radiate radio-frequency energy through cables that are connected to it. This energy may interfere with radio and tele vision reception. Do not leave any cable s connected to it when you are not communicati ng with the controller.
Follow these steps to establish a local connectio n for setting the controller’s initial configuration:
Figure 2–2.
a. For a PC connection, plug one end of the maintenanc e port
cable into the terminal; plug th e o ther end into the controller’s maintenance port.
a. For a t er mi nal con nec ti on, ref er to Figure 1–4 on pag e 1–10 for
cabling information.
parity.
4. Press the Enter or Return key. A copyright notice and the CLI prompt appear, indicating that you established a local connection with the controller.
5. Optional: to inc r ea se the data transfer rate to 19200 baud:
a. Set the controller to 19200 baud with one of the following
commands:
SET THIS_CONTROLLER TERMINAL SPEED=19200 SET OTHER_CONTROLLER TERMINAL SPEED=19200
b. Configure the PC or terminal for 19200 baud.
When you are entering CLI commands in a dual-redundant controller config uration , remember that the conroll er to which you’re connected is this controller and the remaining controller is the other controller”. See Figure 2–3.
Configuring an HSG80 Array Controller 2–9

Figure 2–3 “This C o n t rol ler and Other Controller

Other controller
This controller
CXO6468B
2–10 HSG80 User’s Guide

Selecting a Failover Mode

When selecti ng a failover mode, use transparent failover if you want the failover to occur without any intervention from the host, or employ multiple-bus failover if you want the host to send comma nds to the companion array co ntroller.

Using Transparent Failo ver

Transparent failover is a dual-redundant controller configuration in which two controllers are connected to the same host and device buses. Use this configuration if you want to use two controllers to service the entire group of storagesets, single-dis k units, and other storage de vices. Because both cont rollers service the sa me storage units, either controller can contin ue to service all of the units if its comp anion controller fails.
Transpare n t fa il ove r o cc u rs when a con tro ll er fails or a us er pr e ss es the reset button on one of the controllers. To configure controllers for transpare nt failover, moun t both controllers in the s am e BA370 pedestal and fo llow th e steps in “Configuring an HSG80 Array Cont roller, page 2–3.
Keep the following tips in mind if you configure controllers for transparent failover:
n
Set your controllers for transparent fail over before conf iguring devices. Once the devices, storagesets, and units are added to one controller’s configuration, they are automatically added to the other’s.
n
If you decide to configure your devices before setting the contr o llers fo r tr a n s p arent failover, ma ke sure y ou kn ow which controller ha s the good conf igu ration i nformat ion before spec ifying SET FAILOVER COPY=. See Appendix B, CLI Commands, for details about the SET FAILOVER COPY= command.
n
Balance your assignment of devices. F or example, in an18-device subsystem, place 3 devices on each of the 6 ports, rather than placing 6 de vices on each of 3 ports.
n
The controller to whi ch you c opy confi gura tion in format ion r estarts after you enter the SET FAILOVER command.

Using Multiple-Bus Fail over

Multiple-bus (or host-assisted) failover is a dual-redundant controller configuration in which each array controller has its own connection to the host. Thus, if one of the host connections to an array c ontroller fails, the host can cause units that became inacces sible to failover to the remaining viable connection. Be cause both array controllers service t he same storage unit s, either array controller can continue to service all of the units if the other array controller fails.
Keep the following points in mind when considering using multiple-bus failover:
n
n
n
n
Configuring an HSG80 Array Controller 2–11
The host distributes the I/O load between the array controllers. The host must have two Fibre Channel adapters as well as
operating-system software to support the multiple-bus failover, dual-redundan t controller configuration.
Mount both array cont rollers in the same BA370 rack-mountable enclosure and follow the steps in Configuring a n HSG80 Array Controller, page 2–3.
Partit ioning is not supported.
2–12 HSG80 User’s Guide

Enabling Mirrored Write-Back Cache

Before configuring dual-redundant c ontrollers and enabling mirro ring, ensure the following conditions are met:
n
Both array controllers support the same size cache, 64 MB, 128 MB, 256MB, or 512 MB.
n
Diagnostics indicates that both caches are good.
n
Both caches have a battery present, if you have not enabled the CACHE_UP S switch. A battery does not have to be present for either cach e if you e n able the CACHE_UPS switch.
n
No unit errors are outstanding, for example, lost data or data that cannot be writte n to devices.
n
Both array controllers are started and c onfigured in failover mode.
For important considerations when addi ng or replacing DIMMs in a mirro r ed cache con figuration, see Replacing DIMMs, page 5–42.

Selecting a Cache Mode

Before selecting a cache mode you should understand the caching techniques su pported by the cache module.

Fault-Tolerance

The cache module supports read, read-ahead, write-through, and write­back caching t echniques that you ca n enable separately for each storage unit in a subsystem. For example, you can enable only read and write­through cachin g for some units while enabling only write-back caching for other units.
For details about these caching techniques, seeCaching Techniques, page 1–20.
The cache module supports the following features to protect the availability of its unwritten (write-back) data:
n
Nonvolatile memory (required for write-back caching).
n
Dynami c caching te ch n i qu e s (a u tom a ti c) .
For details about the se fea tures, see Fault-Tolerance for Write-Back Caching, page 1–21.

Backing up Power with a UPS

By defau lt , th e con t r o ll er expects to use an ext er n a l cache batte r y (ECB) as backup power to th e cache module. You can also opt to use an uninterruptable power supply (UPS) to provide backup power in the event of a primary power failure. See Appendix B, “CLI Commands,” for details about the SET THIS_CONTROLLER CACHE_UPS command. See Table 1-7 on page 1–22 and Table 1-8 on page 1–24 for information about cache policies.
Configuring an HSG80 Array Controller 2–13
2–14 HSG80 User’s Guide

Connecting the Subsystem to the Host

This sectio n des cribes how to connect your subsystem to a host. It also includes instructions for connecting a single (nonredundant) controller and dual-redunda nt controllers to the host.
Caution Do not attempt to configure dua l-redundant controllers using one hub with a loopback cable. This configuration will cause data corruptio n and is not supported.

Connecting a Single Controller to the Host Using One Hub

There are two possible configurations for a single controller, one tha t uses a single hub, and a second that uses two hubs. The second config uration can be used if you have two hosts to which you’re connecting to your controller.
Figure 2–4 Cabling for Single Configuration with Fibre Channel Copper Support
1
2
1 2 3 4 5 6
3
To host
CXO6115A
Table 2–1 Key t o Fig u re 2–4 Cabling for Single Configuration
(copper)
Item Description Part No.
1 Single Cont roller 70-3 3259-xx 2 9-Port Fibre Channel HUB DS-DHGGA-CA 3 5-meter copper Fibre Channel cable or
10-meter copper Fibre Channel cable
17-04718-06 17-04718-07
Configuring an HSG80 Array Controller 2–15
Use the follo wing steps to connect a sing le, nonredundant controller to the host using one hub:
1. Stop all I/O from the host to its devices on the bus to which you are connecting the controller.
2. Connect the Fibre Channel cable from Port 1 on the controll er to P ort 1 of the hub.
For this configuration, set Port 2 off-line using the SET THIS_CONTROLLER PORT_2_TOPOLOGY=OFFLI NE command. See Appendix B, CLI Commands, for details about the SET command.
3. Follow the procedures in the Getting Started Guide for connecting the Fibre Channel ca ble from the hub to your host system.
4. Route and tie the cables as desired.
Restart the I/O from the host. Some operating systems may requi re you to restar t the host to see the devices atta ched to the new contr oller .
Figure 2–5 Cabling for Single Configuration with Fibre Channel Optical Support
3
To host
1
1 2 3 4 5 6
2
CXO6495A
2–16 HSG80 User’s Guide
Table 2–2 Key t o Fig u re 2–5 Cabling for Single Configuration
(optical)
Item Description Part No.
1 Single Cont roller 70–33259–xx 2 .5 M Fibre Channel Optic cable
1 M Fibre Channel Optic cable 2 M Fibre Channel Optic cable 3 M Fibre Channel Optic cable
5 M Fibre Channel Optic cable 10 M Fibre Channel Optic cable 20 M Fibre Channel Optic cable 30 M Fibre Channel Optic cable 50 M Fibre Channel Optic cable
100 M Fibre Channe l Op tic cable 200 M Fibre Channe l Op tic cable 400 M Fibre Channe l Op tic cable
17–04820–01 17–04820–02 17–04820–03 17–04820–04 17–04820–05 17–04820–06 17–04820–07 17–04820–08 17–04820–09 17–04820–10 17–04820–11 17–04820–12
3 12-Port Fibre Channel HUB DHGGA-CA
Use the follo wing steps to connect a sing le, nonredundant controller to the host using one hub:
1. Stop all I/O from the host to its devices on the bus to which you are connecting the controller.
2. Connect the Fibre Channel cable from Port 1 on the controller to Port 1 of the hub.
For this configuration, set Port 2 off-line using the SET THIS_CONTROLLER PORT_2_TOPOLOGY=OFFLI N E command. See Appendix B, CLI Commands, for details about the SET command.
3. Follow the procedures in the Getting Started Guide for connecting the Fibre Channel ca ble from the hub to your host system.
4. Route and tie the cables as desired.
5. Restart the I/O from the host. Some operating systems may requi re you to restar t the host to see the devices atta ched to the new contr oller .
Configuring an HSG80 Array Controller 2–17

Connecting a Dual-Redundant Contr oller Configuration to the Host

There are two possible ways to connect dual-re dundant controllers to your host. The first method requires two hubs; the second method requires one hub.
Using Two Hubs
Use the followin g steps and Fig u r e 2 –6 to connect your dual-redundant controllers to the host using two hubs with copper support.
Figure 2–6 Cabling for Dual-Redundant Configuration with Two Hubs using Fibre Channel
Copper Support
1
To host
2
1 2 3 4 5 6
1 2 3 4 5 6
To host
3
2
Table 2–3 Key t o Fig u re 2–6 Cabling for Dual-Redundant
Configuration with Two Hubs (copper)
Item Description Part No.
1Dual Controller 2 9-port Fibre Channel HUB DS–DHGGA–CA 3 5-meter ho st F ibr e Ch a n ne l cable
10-meter host Fibre Channel cable
17–04718–06 17–04718–07
CXO6167A
2–18 HSG80 User’s Guide
1. Stop all I/O from the host to its devices on the bus to which you are
2. Connect the Fibre Channel cable from Port 1 on controller A to Port 9
3. Connect anot her Fibre Channe l c able from Port 2 on cont roll er A to Por t
4. Connect each hub to their respective host according to the instructions
5. Route and tie the cables as desired.
connecting the controllers.
on hub 1. Repeat this step to connect the second cable from Port 1 on controller B to Port 8 on hub 1.
1 on hub 2. Repeat this step to connect the final cable from Port 2 on controller B to Port 2 on hub 2.
in the Getting Started manual.
Restart the I/O from the host. Some operating systems may requi re you to restar t the host to see the devices atta ched to the new contr oller .
Configuring an HSG80 Array Controller 2–19
Use the followin g steps and Fig u r e 2 –7 to connect your dual-redundant controllers to the host using two hubs with optical support:
Figure 2–7 Cabling for Dual-Redundant Configuration with Two Hubs using Fibre Channel
Optical Support
2
To host
1
1 2 3 4 5 6
2
1 2 3 4 5 6
3
To host
CXO6496A
2–20 HSG80 User’s Guide
Table 2–4 Key t o Fig u re 2–7 Cabling for Dual-Redundant
Configuration with T wo Hubs (optical)
Item Description Part No.
1Dual Controller 2 12-Port Fibre Channel HUB DHGGA-CA 3 .5 M Fibre Channel Optic cable
1 M Fibre Channel Optic cable 2 M Fibre Channel Optic cable 3 M Fibre Channel Optic cable
5 M Fibre Channel Optic cable 10 M Fibre Channel Optic cable 20 M Fibre Channel Optic cable 30 M Fibre Channel Optic cable 50 M Fibre Channel Optic cable
100 M Fibre Channe l Op tic cable 200 M Fibre Channe l Op tic cable 400 M Fibre Channe l Op tic cable
17–04820–01 17–04820–02 17–04820–03 17–04820–04 17–04820–05 17–04820–06 17–04820–07 17–04820–08 17–04820–09 17–04820–10 17–04820–11 17–04820–12
1. Stop all I/O from the host to its devices on the bus to which you are connecting the controllers.
2. Connect the Fibre Channel cable from Port 1 on controller A to Port 9 on hub 1. Repeat this step to connect the second cable from Port 1 on controller B to Port 8 on hub 1.
3. Connect anot her Fibre Channe l c able from Port 2 on cont roll er A to Por t 1 on hub 2. Repeat this step to connect the final cable from Port 2 on controller B to Port 2 on hub 2.
4. Connect each hub to their respective host according to the instructions in the Getting Started manual.
5. Route and tie the cables as desired.
6. Restart the I/O from the host. Some operating systems may requi re you to restar t the host to see the devices atta ched to the new contr oller .
Configuring an HSG80 Array Controller 2–21
Using One Hub
Use the followin g steps and Fig u r e 2 –8 to connect your dual-redundant controllers to the host using one hub with copper support:
Figure 2–8 Cabling for Dual-Redundant Configuration with One
Hub using Fibre Channel Copper Support
1
1 2 3 4 5 6
1 2 3 4 5 6
3
2
To host
CXO6234A
Table 2–5 Key t o Fig u re 2–8 Cabling for Dual-Redundant
Configuration with One Hub using Fibre Channel Copper Support
Item Descri ption P art No.
1Dual Controller 2 9-port Fibre Channel HUB DS-DHGGA-CA 3 5-met er hos t F ibr e Ch a n ne l cable
10-meter host Fibre Channel cable
17-04718-06 17-04718-07
1. Stop all I/O from the host to its devices on the bus to which you are connecting the controllers.
2. For this configuration, set Port 2 off-line using the SET THIS_CONTROLLER PORT_2_TOPOLOGY=OFFLI NE command. See Appendix B, CLI Commands, for details about the SET command.
2–22 HSG80 User’s Guide
3. Connect the Fibre Channel cable from Port 1 on controller A to Port 9 on hub 1. Repeat this step to connect the second cable from Port 1 on controller B to Port 8 on hub 1.
4. Connect anot her Fibre Channe l c able from Port 2 on cont roll er A to Por t 1 on hub 2. Repeat this step to connect the final cable from Port 2 on controller B to Port 2 on hub 2.
5. Connect each hub to their respective host according to the instructions supplied in the Getting Started manual.
6. Route and tie the cables as desired.
7. Restart the I/O from the host. Some operating systems may requi re you to restar t the host to see the devices atta ched to the new contr oller .
Use the followin g steps and Fig u r e 2 –9 to connect your dual-redundant controllers to the host using one hub with copper support:
Figure 2–9 Cabling for Dual-Redundant Configuration with One Hub using Fibre Channel
Optical Support
1
1 2 3 4 5 6
1 2 3 4 5 6
3
To host
2
CXO6497A
Configuring an HSG80 Array Controller 2–23
Table 2–6 Key t o Fig u re 2–9 Cabling for Dual-Redundant
Configuration with One Hub using Fibre Channel Optical Support
Item Description Part No.
1Dual Controller 2 12-Port Fibre Channel HUB DHGGA-CA 3 .5 M Fibre Channel Optic cable
1 M Fibre Channel Optic cable 2 M Fibre Channel Optic cable 3 M Fibre Channel Optic cable
5 M Fibre Channel Optic cable 10 M Fibre Channel Optic cable 20 M Fibre Channel Optic cable 30 M Fibre Channel Optic cable 50 M Fibre Channel Optic cable
100 M Fibre Channe l Op tic cable 200 M Fibre Channe l Op tic cable 400 M Fibre Channe l Op tic cable
17–04820–01 17–04820–02 17–04820–03 17–04820–04 17–04820–05 17–04820–06 17–04820–07 17–04820–08 17–04820–09 17–04820–10 17–04820–11 17–04820–12
1. Stop all I/O from the host to its devices on the bus to which you are connecting the controllers.
2. For this configuration, set Port 2 off-line using the SET THIS_CONTROLLER PORT_2_TOPOLOGY=OFFLI NE command. See Appendix B, CLI Commands, for details about the SET command.
3. Connect the Fibre Channel cable from Port 1 on controller A to Port 9 on hub 1. Repeat this step to connect the second cable from Port 1 on controller B to Port 8 on hub 1.
4. Connect anot her Fibre Channe l c able from Port 2 on cont roll er A to Por t 1 on hub 2. Repeat this step to connect the final cable from Port 2 on controller B to Port 2 on hub 2.
5. Connect each hub to their respective host according to the instructions supplied in the Getting Started manual.
6. Route and tie the cables as desired.
7. Restart the I/O from the host. Some operating systems may requi re you to restar t the host to see the devices atta ched to the new contr oller .

CHAPTER 3

Creating Storagesets

This chapter provides information to help you create storagesets for your subsystem. Th e proc edure in this chapter takes you through the planni ng steps and procedures for creating storagesets.
3–1
3–2 HSG80 User’s Guide

Introduction

Storagesets are implementations of RAID technology, also known as a Redundant Array of Independent Disks. Every storageset shares one important feature: each one looks lik e a single storage unit to the host, regardless of the number of drives it uses .
You can create storage units by combining disk drive s into storagesets, such as str i p esets, RAID sets, and mir ro rsets, or by presenting th em to the host as sing le-disk units, as shown in Figure 3–1.
n
Stripesets (RAID 0) combine dis k d r ives in serial to increase transfer or request rat es.
n
Mirror s et s ( RA I D 1) combin e d isk dr ives in p ar a ll el to pr ovid e a highly-reliable storage unit.
n
RAIDsets (RAID 3/5) combine disk drives in serial—as do stripesetsbut also store pa rity data to ensure high reliabi lity.
n
Striped mirrorsets (RAID 0+1) combine mirrorsets in seri al to provide the highest throughput and availability of any storage unit.
Controllers can support the number of RAIDsets as lis ted in Table 3-1.
For a complete discussion of RAID, refer to The RAIDBOOK A Source Book for Disk Array Technology.
Creating Storagesets 3–3
Figure 3–1 Units Created from Storagesets, Partitions, and
Drives
Unit
Unit
Stripeset
Mirrorset
RAIDset
Disk drives
Unit
Table 3–1 Controller Limitations for RAIDsets
RAIDset Type Limit
Total number of RAID5 20 Total number of RAID5 + RAID1 30 Total number of RAID5 + RAID1 + RAID0 45
Partitioned disk drive
Unit
Unit
Partitioned storageset
Unit
Striped mirrorset
CXO5368B
3–4 HSG80 User’s Guide

Planning and Configuring Storagesets

Use this procedure to plan and configure the storagesets for your subsystem. Use the references in each step to lo ca te details about specific co mmands an d co nc ep t s .
1. Create a storageset and device profile. See Creating a Storagese t and Device Profile, page 3–5, for suggest ions about creating a profile.
2. Determine your storage requirements. Use the questions in Determining Storage Requirements, page 37, to help you.
3. Choose the type of storagesets you need to use in your subsystem. See Choosing a Storage set Type, page 38, for a comparison and description of ea ch type of storageset.
4. Select names for your storagesets and units. See Creating a St or a g es e t Map, page 3–32, for details about selecting names.
5. Assign unit numbers to storagesets so the host can access the units. SeeCreating a Storageset Map, page 3–32, for information about how to assign units numbers to storagesets.
6. Create a storageset map to help you configure your subsystem. See Creating a Storageset Map, page 332, for suggestions about creating a storageset map.
7. If you are going to parti tion your storagesets, pl an the partitions. See Planning Partitions, page 337, for information about partitions and how to plan for them.
8. Choose the switc hes that you will want to set for your stora ges ets and device s. SeeChoosing Switches for Stor age sets and Devices, page 3–39, for a description of the switches you can select for storagesets.
9. Configure the storagesets you have planned using one of these methods:
n
Use StorageWorks Command Console (SWCC), a Graphical User Interface (GUI) , to set up and manage RAID storage subsystems. See t h e SWCC Getting St arted guide for details about using SWCC to configure your storagesets.
n
Use CLI commands. This method allows you flexibility in defining and naming storagesets. See Configuring Storagesets with CLI Commands,” page 3–55, for informat ion about configuring each type of storages et using CLI commands.

Creating a Storageset and Device Profile

Creating a profile for your storagesets and devices c an help simplify the config uration process. This chapter helps you to choose the s toragesets that best suit your needs and make informed decis ions about the switches that you ca n enable for each storageset or stora ge device that you configure in your subsystem.
Familiarize yourself with the kinds of information contained in a storageset profile, as shown in Figure 3–2.
Appendix A, System Profiles, contains blank profiles that you can copy and use to record the de tails for your storageset s. Use the information in this chapter to help you make decisions when creating storageset profiles.
Creating Storagesets 3–5
3–6 HSG80 User’s Guide

Figure 3–2 A Typical Storage s et Profile

Type of st o r ageset
_____ Mirrorset ___ RAIDset _____ Stripeset _____ Strip ed Mirrorset
St orageset Name... accept default values
Disk Drives............ DISK10300, DISK20300, DIS30300
Unit Number....... .. acc e p t d e fa ul t
Partitions
Unit # Unit # Unit # Unit # Unit # Unit # Unit # Unit #
%%%%%%%%
RAIDset Sw itches
Reconstruction Policy Reduced Membership Replacement Policy
_ Normal (default) ___ Fast
_No (default) ___ Yes, missing:
_ Best perf ormance (default) ___ Best fit ___ None
Mirrorset Switches
Replacement Policy C opy Policy Read Source
___ Best performance (default) ___ Best fit ___ None
___ Normal (default) ___ Fast
___ Least busy (default) ___ Round robin ___ Disk drive:
Initialize Switch es
Chunk size Save Configur ation Metadata
Automatic (defau lt) ___ 64 blocks ___ 128 blocks ___ 256 blocks ___ Other:
___ No (default)
Yes
_
Unit Switches
Read Cache Read-Ahead Cache Maximum Cache Transfer
Yes (default)
___ No
Write Cache Write Protection Availability
___ Yes (default)
No
✔ Yes (default) ___ No
No (defau lt)
___ Yes
✔ 32 blocks (default) ___ Other:
✔ Run (default) ___ NoRun
Destroy (defau lt)
___ Retain

Determining Storage Requirements

Start the planning process by determining your storage requirements. Here are a few of the quest ions you should ask yourself:
n
What applications or user groups will access the subsystem? How much cap acity do they ne ed ?
n
What are the I/O requirements? If an application is data-transfer intensive, what is the required transfer rate ? I f it is I/O-request intensive, what is the required res ponse time? What is the read/ write ratio for a typical request ?
n
Are most I/O requests directed to a small percentage of the disk drives? Do you want to keep it that way or balance the I/O load?
n
Do you store mission-critical data? Is availability the highest priority, or would standard backup procedures suffice?
Use your responses to these questions along with Figure 3–2 to determine the types of storagesets you should create to satisfy your organizations requirements.
Creating Storagesets 3–7
3–8 HSG80 User’s Guide

Choosing a Storagese t Type

Different applications may have different storage requirements, so you will probably want to configure more tha n one kind of storageset in your subsystem.
All of the storages ets described in this book impl em ent RAID (Redundant Array of Independent Disks) technology. Consequently, they all share on e important feature: each storag eset, whether it contains tw o dis k drives or ten, looks like one large, virtual disk drive to the ho s t.
Ta ble 3–2 compares differen t kinds of storagesets to help you determine which ones satisfy your requirements.

Table 3–2 A Comparison of Different Kinds of Storagesets

Request Rate (Read/Write)
I/O per second
Identical to single disk drive
Excellent if used with large chunk size
Storageset
Array of disk driv es (JBOD)
Stripeset
(RAID 0)
Relative
Availability
Equivalent to a single disk dr ive
Proportionate to number of disk drives; w ors e th an single disk dr ive
Mirrorset
Excellent Good/Fair Good/Fair System drives;
(RAID1) RAIDset
Excellent Excelle nt/Fa ir Good/Poor High request rat es,
(RAID 3/5) Striped Mirrorset
Excell ent Excellen t if u sed
with large chunk
(RAID 0+1)
size
For a comprehensive discussion of RAID, refer to The RAIDBOOKA Source Book for Disk Array Technology.

Using St r i p e sets to Increase I/ O Performanc e

Stripesets en hanc e I/O performance by spreading the data across multiple di sk drives. Each I/O requ est is broken into small segments
Transfer Rate
(Read/Writ e) MB
per second
Identical to single disk drive
Excellent if used with small chunk size
Excellent if used with small chunk size
Applications
High performance for non-critical data
critical files
read-intensive, data lookup
Any critical response-time application
Creating Storagesets 3–9
called chunks. These chunks are then “striped” across the disk dr ives in the storageset, thereby allowing several disk drives to participate in one I/O request to handl e s everal I/O requests si mul taneously.
For example, in a three-member stripeset that contains disk drives 10000, 20000, and 30000, the first chunk of an I/O request is written to 10000, the s econd to 20000, the third to 30000, the fourth to 10000, and so forth until all of the data has been written to the drives.
Figure 3–3 Striping Lets Several Disk Drives Parti cipate in Each
I/O Request
6
Chunk 1
1
2
3
0
0
1
0
k
0
s
i
D
4
0
2
0
k
0
s
i
D
2
5
5
4
0
3
0
k
0
s
0
i
D
36
0
CXO5507A
The relationship between the chunk size and the average request size determines if striping maximizes the request rat e or the data-transfer rate. You can set the chunk size or let the controller set it autom atically. See Chunk Size, page 3–47, for information about setting the chunk size.
A major benef it of striping is that it balanc es the I/O load across all of the disk d r ives in the storageset. This can increase the subsystem’s performance by el im inating the hot spots, or high localities of reference, that occ ur when frequently-accessed data beco mes concentrat ed on a single disk drive.
3–10 HSG80 User’s Guide
Considerations for Planning a Stripeset
Keep the following points in mind as you plan your stripesets:
n
A controller can supp ort up to 45 storagesets, consisting of stripesets, mirrorsets and RAIDsets (refer to Table 3–1).
n
Reporting methods and size limitati ons prevent certain operating systems from working with large stripesets. See the HSG80 Array Controller ACS Version 8.2G Rel eas e Notes or the Getting Start ed Guide that came with your platform kit for details about these restrictions.
n
A storageset should only contain disk drives of the same capacity. The cont ro ller l imit s t he c apa ci ty of ea ch mem ber to th e ca pa ci ty of the smallest member in the storageset when the storageset is initialized (the base member s ize). Thus, if you c omb ine 9 GB disk drives with 4 GB disk drives in the same storageset, the 4 GB disk drive will be the base member size, and you will waste 5 GB of capacity on eac h 9 GB member.
If you need high performance and high av ail ability, consider using a RAIDset, stripe d mi rrorset, or a host-based shadow of a stripeset.
n
Striping does not protect against data loss. In fact, because the failure of one memb er is equivalent to the failur e of the entire stripeset, the likelihood of losing data is higher for a stripeset than for a singl e di s k drive.
For ex ample, if t he mean time between f ai lures (MTBF) for a si ngle disk is one hour, then the MTBF for a stripeset that comprises N such disks is l/N hours. As another example, if a single disk’s MTBF is 150,000 hours (about 17 years), a stripeset comprising four of the se disks woul d only have an MTBF of slightly more than four years.
For this reason, you should avo id using a stripeset to sto re critical data. Stripesets are more suitable for storing data that can be reproduced easily or whose loss does not prevent the system from supporting its critical mission.
n
Evenly di st r ibut e th e m e mb er s ac r o ss th e dev ic e p orts to balanc e load and provide multiple paths as shown in the Figure 3–4.
Figure 3–4 Distri but e M e mb e rs across Port s
Device ports 2
1
3
6
5
4
Backplane
Creating Storagesets 3–11
3
2
1
0
n
Stripesets contain between 2 and 24 members.
n
Stripesets are well-suited for the following applicat ions:
n
Storing program image libraries or run-t im e libraries for rapid
2 0 1 0 0
1 0 0 0 0
1
2
4 0 3 0 0
3 0 2 0 0
3
4
5
6
loading
n
Storing large tables or other structures of read-only data for rapid application access
CXO6235A
n
Collect ing data fr om ex ter nal sour ces a t very high data tra ns fer rates
n
Stripesets are not well-suited for the following applica tions:
n
A storage solution for data that cannot be easily reproduced or for data that must be available for system operation
3–12 HSG80 User’s Guide
n
Applications that make requests for small amo unts of sequentially-located data
n
Application s that make s ynchrono us rand om reque sts for sm all amounts of data
By spreading the t r affic even ly across the buse s, you will en sure that no bus handles the majority of data to the storageset.

Using Mirrorsets to Ensure Availability

Mirrorsets use redundancy to ensure availability, as illustrated in Figure 3–5. For each pr i m a ry dis k drive, th er e is at least on e mirror disk dr ive. Thus, if a primary disk d r ive fails, its mirror drive immediately pro vides an exact copy of the data.
Figure 3–5 Mirrorsets Maintain T w o Copies of the Same Data
0
1
1
k
0
s
i
0
D
2
0
1
k
0
s
i
0
D
B
3
0
1
k
0
s
i
0
D
1
0
0
k
0
s
i
0
D
A'A
0
2
0
k
0
s
i
0
D
B'
3
0
0
k
0
s
i
D
0
C'C
Mirror drives contain copy of data
CXO5511A
Considerations for Planning a Mirrorset
Keep these points in mind as you plan your mirrorsets:
n
A controller can supp ort up to 30 storagesets, consisting of mirrorsets and RAIDsets. Mirrorsets that are members of a stripeset count against this limitation (refer to Table 3–1).
n
Data availability with a mirrorse t is excellen t but costly you need twice as many dis k dr iv es to sati sfy a given capacity re quire ment. If availability is your top priority, consider using redundant power supplies and dual-redundant controllers.
Creating Storagesets 3–13
n
You can configure up to 30 mirrorsets per controller or pair of dual­redundant controllers. Each mirrorset contains a minimum of one and a maximum of six members.
n
A write-back cache modul e is required for mirrorsets, but write­back cache need not be enabled for the mirrorset to function properly.
n
Both write-back cache modules must be the same size.
n
If youre using more than one mirrorset in your subsystem, you should put the first member of each mirrorset on different buses as shown in F ig ure 3–6. (The first member of a mirrorset is the first disk drive you add.)
When a controller r ecei ve s a request to read data f rom a mirrorset, it typically accesses the first member of the mirrorset. Read access depends upon the read source switches, as described in “Read Source, page 3–43. If you have several mirrorsets in your subsyst em and the ir f irs t me mbe rs ar e on the sam e b u s, t hat b us wil l be forced to handle the majority of traf fic to your mirrorsets. Wh en a contr o ller rece ives a request to write data to a mirrorset, it accesses and writ es to all memb er s.
Figure 3–6 First Mirrorset Members on Different Buses
First member of Mirrorset 1
First member of Mirrorset 2
CXO5506A
To avoid an I/O bottleneck on one bus, you ca n si mpl y put the first members on different buses. Additionally, you can set the read­source swit ch to Round Robin. See Read Source, page 3–43, for more information about this switch.
n
Place mirrorsets and RAIDs ets on different ports to minimize risk in the event o f a si ng l e p or t bus fa il u re .
3–14 HSG80 User’s Guide
n
Mirro r set units ar e se t to W R I TE BACK _ C ACH E by default wh ich increases a units performance.
n
A storageset should only contain disk drives of the same capacity. The cont ro ller l imit s t he c apa ci ty of ea ch mem ber to th e ca pa ci ty of the smallest member in the storageset. Thus, if you combine 9 GB disk dr ives with 4 GB disk drives in th e same storageset, the 4 GB disk drive will be the base member size, and you waste 5 GB of capacity on eac h 9 GB member.
n
Evenly di st r ibut e th e m e mb er s ac r o ss th e dev ic e p orts to balanc e load and provide multiple paths as shown in Figure 3–4 on page 3–11.
n
Mirrorsets are well-sui te d for the following:
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Any data for which reliability requirements are extremely high
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Data to which high-performance access is required
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Applications for which cost is a secondary issue
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Mirrorsets are not well-suited for the following applications:
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Write-intensive applications ( JBODs are better for this type of application, but mirrorsets are preferred over Raid5 RADsets .)
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Applicat ions for which cost is a primary issue

Using RAIDsets to Increase Pe rformance and Availability

RAIDsets are enhanced stripesetsthey use striping to increase I/O performance and distributed-parity data to ensure data availability. Figure 3–7 illustra tes the concept of RAI D sets and parity data.
Figure 3–7 Parity Ensures Availability; Striping Provides Good
Performance
I/O Request
Chunk 1
2
3
Creating Storagesets 3–15
4
Chunk 1
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k
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s
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Parity for 1 & 2
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Just as with stripesets, the I/O requests are broken into smaller chunks and striped ac ross the disk drives until the request is rea d or written. But, in addition to the I/O data, chunks of pa rity data—derived mathema tically from the I/ O d ataare also striped across the disk drives. This parity data enables the c ontroller to reconstruct the I/O data if a disk drive fails. Thus, it becomes possible to lose a disk drive witho ut lo s i ng access to th e da ta it con t ai n ed . ( D at a co u ld be los t if a second disk dri ve fails before the controller repla ces the first failed disk drive.)
For example, in a three-member RAIDset that contains disk drives 10000, 20000, and 30000, the first chunk of an I/O request is written to 10000, the second to 20000, then parity is calculated and written to 30000; the third chunk is written to 30000, the fourth to 10000, and so on until all of the data is saved.
3–16 HSG80 User’s Guide
The relationship between the chunk size and the average request size determines if striping maximizes the reques t rat e or the data-transfer rates. You can set the chunk size or let the controller set it automatically. See “Chunk Size,” page 3–47, for information abo ut setting the chunk size.
Considerations for Planning a RAIDset
Keep these points in mind as you plan your RAIDsets :
n
A controller can supp ort up to 20 storagesets, consisting of RAIDsets (refer to Table 3–1).
n
Reporting methods and size limitati ons prevent certain operating systems from working with large RAIDsets. See the HSG80 Arra y Controller ACS Version 8.2G Rel eas e Notes or the Getting Start ed Guide that came with your platform kit for details about these restrictions.
n
A cache module is requir ed for RAIDsets, but write-back cache need not be enabled for th e RAIDset to function properly.
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Both cache modules must be the same si ze.
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A RAIDset must include at least 3 disk drives, but no more than 14 .
n
Evenly di st r ibut e th e m e mb er s ac r o ss th e dev ic e p orts to balanc e load and provide multiple paths as shown in Figure 3–4 on page 3–11.
n
A storageset should only contain disk drives of the same capacity. The cont ro ller l imit s t he c apa ci ty of ea ch mem ber to th e ca pa ci ty of the smallest member in the storageset when the storageset is initialzed (the base member size). Thus , if you combine 9 GB disk drives with 4 GB disk driv es in the same storageset, you will waste 5 GB of capacity on each 9 GB member.
n
RAIDset units are set to WRITEBACK_CACHE by default which increases a units performance.
n
RAIDsets and mirror se ts on different ports to minimize risk in the event of a s ingle po r t bus fail ur e.
n
RAIDsets are particularly well-suited for the following:
n
Small to medium I/O requests
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Applications requiring high a vailability
Creating Storagesets 3–17
n
High read request rates
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Inquiry-typ e tra nsaction processing
n
RAIDsets are not particularly well-suited for the following:
n
Write-intensive applications
n
Applications that require high data tr ansfer capacity
n
High-speed data collection
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Database applications in which fields are continually updated
n
Transaction processing

Using Striped Mirrors ets f or Highe s t P er f or mance and Availability

As illustra ted in Figure 3–8, striped mirrorsets are simply strip es ets whose members are mirrorsets. Consequently, this kind of storageset combines the performance of striping with the reliability of mirroring. The result is a storages et with very high I/O performance and high dat a availability.
Figure 3–8 Striping and Mirroring in t he Same Storageset
Stripeset
Mirrorset1 Mirrorset2 Mirrorset3
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The failu r e of a sin g l e di s k drive h as no effec t o n th i s s to rag eset’s ability to deliver data to the host and, under normal circumstances, it has very little effect on performance. Because striped mirrorsets do not
3–18 HSG80 User’s Guide
require any more disk drives than mirrorsets, this storageset is an excellent choice for data that warrants mirroring.
Considerations for Planning a Striped Mirrorset
Plan the m i rro r s e t members, th en pl an th e str i p eset that wil l con t ai n them. Review the recommendations in “Considerations for Planning a Stripeset,” page 3–10, and “Considerations for Plan ning a Mirrorset,” page 3–12.
There are the following limitations for a striped mirrorset:
n
A maximum of 24 mirrorsets in a stripeset.
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A maximum of 6 disks in each mirrorset.
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A maximum of 48 disks in the entire striped mirrorset.

Cloning Data for Backup

Use the CLONE utility to duplicate the data on any unpartitioned single-disk unit, stripeset, mirrorset, or striped mirrorset in preparation for backup. When the cloning operation is done, you can back up the clones rather than the storageset or single-disk uni t, which can continue to service its I/O lo ad. When you are cloning a mirrorset , CLONE does not need to create a te mporary mirrorset. Inste ad, it adds a temporary member to the mirrorset and copies the data onto this new member.
The CLONE uti li ty cr eates a te mpo ra ry, two-member mi rror se t fo r ea ch member in a single-disk unit or stripeset. Each temporary mirrorset contains one disk drive from the unit you are cloning and one disk drive onto which CLONE copies the data . During the cop y operati on, the unit remains online and ac tive so the clones contain the most up-to-date data.
After the CLONE utility copies the data from the member s to the clones, it restores the unit to its original configuration and creates a clone unit you can backup. The CLONE utility uses steps shown in Figure 3–9 to duplicate each member of a unit.
Creating Storagesets 3–19
3–20 HSG80 User’s Guide

Figure 3–9 CLONE Steps for Duplicating Unit Members

Unit
Unit
Temporary mirrorset
Disk10300
Disk10300
New member
Unit
Temporary mirrorset
Unit
o
p
C
y
Disk10300
Disk10300
New member
Clone Unit
Clone of Disk10300
CXO5510A
Use the follo wing steps to clone a single -disk unit, stripes et, or mirrorset:
1. Establish a connection to the controller that accesses the uni t you want to clone.
2. Start CLONE using the following command:
RUN CLONE
3. When prompted, ente r the unit number of the unit you want to clone.
4. When prompted, en ter a un it n umber fo r the cl one uni t t hat CLONE wil l create.
Creating Storagesets 3–21
5. When prompted, in dicate how you would lik e the clone unit to be brought online: either automatically or only after your appro val.
6. When prompted, enter the disk drives you want to us e for the clone units.
7. Back up the clone unit.
Example
This examp le shows the commands you would use to clone storage unit D98. The clone command termin ates after it creates storage un it D99, a clone or copy of D98.
RUN CLONE
CLONE LOCAL PROGRAM INVOKED UNITS AVAILABLE FOR CLONING:101
98
ENTER UNIT TO CLONE ? 98
CLONE WILL CREATE A NEW UNIT WHICH IS A COPY OF UNIT 98.
ENTER THE UNIT NUMBER WHICH YOU WANT ASSIGNED TO THE NEW UNIT ? 99
THE NEW UNIT MAY BE ADDED USING ONE OF THE FOLLOWING METHODS:
1. CLONE WILL PAUSE AFTER ALL MEMBERS HAVE BEEN COPIED. THE USER MUST THEN PRESS RETURN TO CAUSE THE NEW UNIT TO BE ADDED.
2. AFTER ALL MEMBERS HAVE BEEN COP IED, THE UNIT WILL BE ADDED AUTOMATICALLY.
UNDER WHICH ABOVE METHOD SHOULD THE NEW UNIT BE ADDED[]?1
DEVICES AVAILABLE FOR CLONE TARGETS: DISK20200 (SIZE=832317) DISK20300 (SIZE=832317) DISK30100 (SIZE=832317)
USE AVAILABLE DEVICE DISK 20200( SIZE=83231 7) FOR MEMB ER DISK10300(SIZE= 832317) (Y,N ) [Y] ? Y
MIRROR DISK10300 C_MA SET C_MA NOPOLICY SET C_MA MEMBERS=2 SET C_MA REPLACE=DISK220
3–22 HSG80 User’s Guide
DEVICES AVAILABLE FOR CLONE TARGETS: DISK20300 (SIZE=832317) DISK30100 (SIZE=832317)
USE AVAILABLE DEVICE DISK 10400( SIZE=832317 ) FOR MEMB ER DISK10000(SIZE= 832317) (Y,N ) [Y] ? Y
MIRROR DISK10000 C_MB SET C_MB NOPOLICY SET C_MB MEMBERS=2 SET C_MB REPLACE=DISK10400 COPY IN PROGRESS FOR EACH NEW MEMBER. PLEASE BE PATIENT... . . COPY FROM DISK10300 TO DISK10200 IS 100% COMPLETE COPY FROM DISK10000 TO DISK10400 IS 100% COMPLETE
PRESS RETURN WHEN YOU WANT THE NEW UNIT TO BE CREATED
REDUCE DISK10200 DISK10400 UNMIRROR DISK10300 UNMIRROR DISK10000 ADD MIRRORSET C_MA DISK10200 ADD MIRRORSET C_MB DISK10400 ADD STRIPESET C_ST1 C_MA C_MB INIT C_ST1 NODESTROY CHUNK=128 ADD UNIT D105 C_ST1 D105 HAS BEEN CREATED. IT IS A CLONE OF D104. CLONE - NORMAL TERMINATION
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