HP StorageWorks 2/16, StorageWorks 8B, StorageWorks quickloop fabric assist User Manual
user guide
hp StorageWorks
quickloop fabric assist
Product Version: Version 3.0.x
First Edition (February 2003)
Part Number: AA-RTS1A-TE
This document provides an overview of QuickLoop Fabric Assist concepts, instructions for
installing QuickLoop Fabric Assist and zoning, and information about configuring and using
QuickLoop Fabric Assist.
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Quickloop Fabric Assist User Guide
First Edition (February 2003)
Part Number: AA-RTS1A-TE
contents
About this Guide
Intended Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Document Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Text Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Equipment Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Rack Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Getting Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
HP Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
HP Storage Website . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
HP Authorized Reseller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Introducing QuickLoop
QuickLoop Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
QuickLoop Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Address Translation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Combining QuickLoop and Zoning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Installing a QuickLoop
Installation Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Installing a QuickLoop Using Telnet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Installing a QuickLoop Using Web Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Using Quick Loop
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Administering QuickLoop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Web Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3Quickloop Fabric Assist User Guide
Telnet Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
QuickLoop Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
QuickLoop Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Dual-switch QuickLoop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
QuickLoop Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Sample Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Configuration 1: Emulating a Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Configuration 2: Dual-switch QuickLoop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Configuration 3: Long Wave Laser Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Configuration 4: Mixed QuickLoop Mode and Fabric Mode . . . . . . . . . . . . . . . . . . . . . 28
Error Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Switch Level Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Port Level Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Using QuickLoop Fabric Assist Mode
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Characteristics and Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Fault Isolation and Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
How Fabric Assist Mode Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Zone Configuration Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
LIP Propagation and Private Targets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Fabric Assist Mode Hosts and QuickLoop Zoning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Preferred Phantom AL_PA Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
AL_PA Assignment Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Sample Fabric Assist Mode Zone Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Configuration 1: Single Fabric Assist Mode Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Telnet Commands for Configuration 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Configuration 2: Two Fabric Assist Mode Zones in a Fabric . . . . . . . . . . . . . . . . . . . . . 40
Telnet Commands for Configuration 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Contents
Fabric Assist Mode Telnet Commands
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Telnet Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Glossary
Index
4Quickloop Fabric Assist User Guide
This user guide provides information to help you:
■ Installing the optionally-licensed QuickLoop software.
■ Configure the QuickLoop software.
■ Contact technical support for additional assistance.
Intended Audience
This book is intended for use by System Administrators who are experienced with
the following:
■ StorageWorks Fibre Channel SAN Switches.
■ Fabric Operating System V3.0 or later.
about this
guide
Prerequisites
Before you install or configure the software, make sure you consider the items in
the Document Conventions section that follow.
5Quickloop Fabric Assist User Guide
About this Guide
Conventions
Conventions consist of the following:
■ Document Conventions
■ Text Symbols
■ Text Symbols
Document Conventions
The document conventions included in Tabl e 1 apply in most cases.
Table 1: Document Conventions
Cross-reference links Blue text: Figure 1
Element Convention
Text Symbols
Key and field names, menu items,
buttons, and dialog box titles
File names, application names, and text
emphasis
User input, command and directory
names, and system responses (output
and messages)
Variables <monospace, italic font>
Website addresses Blue, underlined sans serif font text:
Bold
Italics
Monospace font
COMMAND NAMES are uppercase
monospace font unless they are case
sensitive
http://www.hp.com
The following symbols may be found in the text of this guide. They have the
following meanings.
WARNING: Text set off in this manner indicates that failure to follow
directions in the warning could result in bodily harm or loss of life.
6 Quickloop Fabric Assist User Guide
Caution: Text set off in this manner indicates that failure to follow directions
could result in damage to equipment or data.
Note: Text set off in this manner presents commentary, sidelights, or interesting points
of information.
Equipment Symbols
The following equipment symbols may be found on hardware for which this guide
pertains. They have the following meanings.
About this Guide
Any enclosed surface or area of the equipment marked with these
symbols indicates the presence of electrical shock hazards. Enclosed
area contains no operator serviceable parts.
WARNING: To reduce the risk of injury from electrical shock hazards,
do not open this enclosure.
Any RJ-45 receptacle marked with these symbols indicates a network
interface connection.
WARNING: To reduce the risk of electrical shock, fire, or damage to the
equipment, do not plug telephone or telecommunications connectors
into this receptacle.
Any surface or area of the equipment marked with these symbols
indicates the presence of a hot surface or hot component. Contact with
this surface could result in injury.
WARNING: To reduce the risk of injury from a hot component, allow
the surface to cool before touching.
Quickloop Fabric Assist User Guide
7
About this Guide
Power supplies or systems marked with these symbols indicate the
presence of multiple sources of power.
WARNING: To reduce the risk of injury from electrical shock,
remove all power cords to completely disconnect power from the
power supplies and systems.
Any product or assembly marked with these symbols indicates that the
component exceeds the recommended weight for one individual to
handle safely.
WARNING: To reduce the risk of personal injury or damage to the
equipment, observe local occupational health and safety requirements
and guidelines for manually handling material.
Rack Stability
Rack stability protects personnel and equipment.
WARNING: To reduce the risk of personal injury or damage to the
equipment, be sure that:
■ The leveling jacks are extended to the floor.
■ The full weight of the rack rests on the leveling jacks.
■ In single rack installations, the stabilizing feet are attached to the rack.
■ In multiple rack installations, the racks are coupled.
■ Only one rack component is extended at any time. A rack may become
unstable if more than one rack component is extended for any reason.
8 Quickloop Fabric Assist User Guide
Getting Help
If you still have a question after reading this guide, contact an HP authorized
service provider or access our website:
HP Technical Support
In North America, call technical support at 1-800-652-6672, available 24 hours a
day, 7 days a week.
Note: For continuous quality improvement, calls may be recorded or monitored.
Outside North America, call technical support at the nearest location. Telephone
numbers for worldwide technical support are listed on the HP website under
support:
Be sure to have the following information available before calling:
http://www .h p.com/country/us/eng / support.html
http://www.hp.com
.
About this Guide
.
■ Technical support registration number (if applicable)
■ Product serial numbers
■ Product model names and numbers
■ Applicable error messages
■ Operating system type and revision level
■ Detailed, specific questions
HP Storage Website
The HP website has the latest information on this product, as well as the latest
drivers. Access storage at:
storage .html
http://www .hp.com/country/us/eng/prodserv/
. From this website, select the appropriate product or solution.
Quickloop Fabric Assist User Guide
9
About this Guide
HP Authorized Reseller
For the name of your nearest HP authorized reseller:
■ In the United States, call 1-800-345-1518
■ In Canada, call 1-800-263-5868
■ Elsewhere, see the HP website for locations and telephone numbers:
http://www.hp.com
.
10 Quickloop Fabric Assist User Guide
Introducing QuickLoop
This chapter provides the following information:
■ QuickLoop Overview on page 11
■ QuickLoop Basics on page 12
■ Address Translation on page 12
■ Combining QuickLoop and Zoning on page 13
QuickLoop Overview
QuickLoop is an optional-licensed product that allows arbitrated loops to be
attached to a fabric. Without modifying their drivers, private targets on the
arbitrated loops can be accessed by public or private hosts elsewhere on the fabric.
1
Note: Fabric Assist mode is not supported in this Version 3.0 release; however, it will
be supported in a future release.
Devices attached to QuickLoop communicate with all other devices attached to
the same QuickLoop. However, private devices attached to QuickLoop
communicate only with devices within the same QuickLoop. Public devices in an
arbitrated loop mode are considered private devices when connected to
QuickLoop ports.
When a zoning license is also purchased, the set of storage devices visible to
specific hosts can be carefully administered.
The QuickLoop and zoning combination allows a private host to fully participate
in a Storage Area Network (SAN).
11Quickloop Fabric Assist User Guide
Introducing QuickLoop
QuickLoop Basics
QuickLoop is a unique Fibre Channel topology that combines arbitrated loop and
fabric topologies. An arbitrated loop supports communication between devices
that are not fabric-aware. Such devices are called private devices, and arbitrated
loops are sometimes called private loops.
QuickLoop allows a SAN Switch 8-EL/16-EL to emulate a hub environment,
while offering the additional benefit of connectivity to a fabric.
A QuickLoop consists of multiple private arbitrated looplets (a set of devices
connected to a single port) that are connected by a fabric. All devices in a
QuickLoop share a single AL_PA bit-map and behave as if they are in one loop.
This allows private devices to communicate with other devices over the fabric,
provided they are in the same QuickLoop.
A particular QuickLoop can be configured to consist of selected devices or
looplets connected to the ports of one switch, or to a cascaded switch pair.
QuickLoop provides a possible migration path starting with deploying a single
private loop and later deploying a fabric-based SAN. In this scenario,
QuickLoop-enabled switches can be used to replace hubs when the SAN is first
deployed and has only private devices attached. Then, as the SAN grows, fabric
switches can be added without any detrimental effect to the QuickLoop-enabled
switches.
Address Translation
Address translation is transparent and requires no actions on the part of the user. It
is achieved through hardware translative mode (also known as phantom mode), in
which a device not physically located in a looplet is made addressable by a unique
AL_PA in that looplet.
Two hardware translative modes are available to a QuickLoop-enabled switch:
■ Standard translative mode—Allows public hosts to communicate with
private target devices across the fabric. Standard translative mode is available
as an integral part of Fabric OS, and does not require QuickLoop.
■ QuickLoop mode—Allows private hosts to communicate with private target
devices across the fabric when configured in the same QuickLoop. Also
allows a private host to communicate with a public target in the same
QuickLoop.
12 Quickloop Fabric Assist User Guide
Individual ports within a switch may be set by configuration commands to one of
the above two modes offering a mixed mode configuration.
The switch automatically determines and sets the appropriate mode, based on
factory defaults and configurations currently in effect.
Combining QuickLoop and Zoning
QuickLoop can be used in conjunction with Zoning.
Zoning allows the zoning of fabrics and QuickLoops. This feature enhances the
management of a Fibre Channel Arbitrated Loop (FC-AL) in a legacy
environment.
In QuickLoop zoning, devices within a QuickLoop can be partitioned within that
QuickLoop to form QuickLoop zones; this means that a QuickLoop zone is a
subset of QuickLoop and can include only devices in QuickLoop.
Fabric zones and QuickLoop zones are independent of each other; both types of
zones can co-exist in the same zone configuration. Hosts in a QuickLoop can see
only targets contained within a QuickLoop.
Introducing QuickLoop
Purchasing a zoning license adds the following features:
■ Devices from multiple QuickLoops can be added to the definition for a fabric
zone. Even an identical AL_PA from two different QuickLoops could be
configured under a fabric zone. Zoning can correctly direct traffic to the
different devices.
■ Additional control over access to QuickLoop devices. Fabric devices in a
zoned fabric can only access the QuickLoop (and fabric) devices that are in
the same zone.
■ Zones can be created within QuickLoops. Zoning can be used to partition
QuickLoops. This creates QuickLoop zones (as opposed to fabric zones),
whose members are identified by either physical port number or AL_PA.
For more information about using Zoning and QuickLoop in conjunction, see the
Zoning User Guide.
13Quickloop Fabric Assist User Guide
Introducing QuickLoop
14 Quickloop Fabric Assist User Guide
Installing a QuickLoop
This chapter provides the following information:
■ Installation Overview on page 15
■ Installing a QuickLoop Using Telnet on page 16
■ Installing a QuickLoop Using Web Tools on page 17
Installation Overview
Installation of aQuickLoop involves the installation of a license on each switch
that you want to enable for a QuickLoop. A license may have been installed on the
switch at the factory. If not, contact your switch supplier to obtain a license key.
QuickLoops require a Compaq StorageWorks Fibre Channel SAN Switch with
Fabric Operating System Version 3.0 or later installed. You can install a
QuickLoop license either through telnet or through Web Tools.
2
15Quickloop Fabric Assist User Guide
Installing a QuickLoop
Installing a QuickLoop Using Telnet
1. Log onto the switch by telnet (see the user guide provided with the hardware
for details), using an account that has administrative privileges.
2. If you want to determine whether a QuickLoop license is already installed on
the switch, type licenseShow on the telnet command line. A list displays
of all the licenses currently installed on the switch. For example:
admin> licenseShow
1A1AaAaaaAAAA1a:
Release v3.0
Web license
Zoning license
Compaq QuickLoop license
If the QuickLoop license is not included in the list, or is incorrect, continue
with step 3 and 4.
3. Enter the following on the command line:
licenseAdd “key”
where “key” is the license key provided to you, surrounded by double quotes.
The license key is case sensitive and must be entered exactly as given.
4. Verify the license was added by entering the following on the command line:
licenseShow
If the QuickLoop license is listed, the feature is installed and immediately
available. If the license is not listed, repeat steps 3 and 4.
16 Quickloop Fabric Assist User Guide
Installing a QuickLoop Using Web Tools
If a Web Tools license is installed, you can install a QuickLoop as follows:
1. Launch a web browser, enter the switch name or IP address in the
Location/Address section of the browser, and press <Enter>. Web Tools
launches, displaying the Fabric View.
2. Click the Admin button on the relevant switch panel. The logon window
displays.
3. Enter a logon name and password with administrative privileges and press
Enter. The Administration View displays.
4. Select the License Admin tab.
5. Enter the license key in the License Key: field
6. Click Add button. The QuickLoop features are available as soon as the license
key is added.
For more information about Web Tools installation, see the Web Tools User Guide,
Version 3.0.
Installing a QuickLoop
17Quickloop Fabric Assist User Guide
Installing a QuickLoop
18 Quickloop Fabric Assist User Guide
Using Quick Loop
This chapter provides the following information:
■ Overview on page 19
■ Administering QuickLoop on page 20
■ QuickLoop Topology on page 21
■ QuickLoop Implementation on page 22
■ Sample Configurations on page 24
■ Error Handling on page 29
3
Overview
Note: For information about creating zones within a QuickLoop, see the
Guide, Version 3.0.
You can enable or disable QuickLoop for either the entire switch or for individual
ports. When QuickLoop is disabled on an individual port, that port returns to
Fabric mode. When QuickLoop is enabled on a port, the port is added to the same
QuickLoop to which the switch belongs.
A QuickLoop is either “single switch,” where all looplets are located on a single
switch, or “dual switch,” where looplets are located on either of two partnered
switches. However, any switch can be in only one QuickLoop. A QuickLoop
includes all or some of the ports on a switch or cascaded switch pair, and can have
several private hosts. Public hosts in an arbitrated loop mode are considered
private devices when connected to QuickLoop ports.
Zoning User
19Quickloop Fabric Assist User Guide
Using Quick Loop
A switch can be configured to operate in any of the following modes:
■ QuickLoop mode—All ports on the switch, except for E_Ports or loopback
ports, are enabled for QuickLoop and participate in a logical Private Loop
Direct Attach (PLDA). Upon request, this can be set as the manufacturing
default. This mode can also be set by the telnet command qlEnable.
■ Fabric mode—No ports are QuickLoop-enabled (none participate in any
logical PLDAs), and all ports operate as FC-FLA compliant devices. This
mode can be set by the telnet command qlDisable.
■ Mixed mode—Each port is set to QuickLoop on an individual basis. The
port’s operating mode can be reset during operation. Ports set to QuickLoop
become looplets of the QuickLoop to which the switch belongs. Particular
ports can be taken in and out of the QuickLoop by the telnet commands
qlPortDisable and qlPortEnable.
Note: These modes cannot be configured by Simple Network Management Protocol
(SNMP).
A switch has a default mode, which depends on the switch model. When powered
up, all the ports of the switch will be set to the default mode.
Administering QuickLoop
You can manage QuickLoops using telnet commands or Web Tools (an optionallicensed product).
Web Tools
You can view and modify the QuickLoop settings through the QuickLoop Admin
tab on the Switch Admin interface view available through Web Tools. For detailed
information about installing and using Web Tools for the QuickLoop feature, refer
to the Web Tools User Guide.
Telnet Commands
The telnet commands for QuickLoop become available through the shell admin
account when the basic QuickLoop license key is installed.
20 Quickloop Fabric Assist User Guide
To use a QuickLoop telnet command, log into the relevant switch with
administrative privileges, enter the command along with any required operands,
and press Enter.
For a description of all the telnet commands provided for managing QuickLoop,
refer to the Fabric Operating System Reference Guide.
QuickLoop Topology
QuickLoop topologies have the following characteristics:
■ A QuickLoop can include up to two switches and can support up to 126
AL_PA devices.
■ Each switch can only be included in one QuickLoop.
■ A QuickLoop can include either all of, or a subset of, the ports on an
individual switch.
■ Multiple non-overlapping QuickLoops can exist in a fabric of multiple
switches.
Using Quick Loop
■ Switches with QuickLoops enabled can exist in the same fabric as
non-QuickLoop enabled switches.
■ A device attached to a QuickLoop can communicate with all other devices
attached to the same QuickLoop.
■ A private device in a QuickLoop can only communicate with devices in the
same QuickLoop. Existing PLDA capable host drivers need no modification
to perform I/O operations with storage devices.
■ Public devices that are arbitrated loop capable are treated as private devices
when connected to QuickLoop ports (their fabric login, or “FLOGI,” is not
valid).
■ Legacy devices may be used in a QuickLoop and may be attached to a fabric
and operate as if in a PLDA environment.
■ A QuickLoop can be enabled or disabled for either the entire switch or for
individual ports. When QuickLoop is disabled on an individual port, that port
returns to Fabric mode.
■ Each looplet in a QuickLoop has its own unshared bandwidth and can support
transfer rates up to 100 MB/s.
21Quickloop Fabric Assist User Guide
Using Quick Loop
■ Multiple devices communicate simultaneously between at least 4 separate
switch ports, at full bandwidth within multiple looplets located in the same
QuickLoop. These simultaneous conversations cannot involve overlapping
looplets.
■ If a looplet error is detected, QuickLoop automatically takes that looplet out
of service. If the error condition is cleared, the looplet is automatically
reinstated.
QuickLoop Implementation
QuickLoop is implemented by a combination of hardware and software
components and requires no actions on the part of the user once it is installed and
configured. The hardware components are responsible for the transport of frames
among looplets and across switches, and the software components are responsible
for QuickLoop initialization and error handling.
Terminology
N_port
NL_port
The terms and concepts introduced in this section are fundamental to
understanding the use of QuickLoop mode with switches. Refer to the Glossary
for aditional terms.
Note: The following two port types are on host or storage devices, not on switches.
(Node port) An equipment port that is not loop capable. Used to connect the
equipment to the fabric.
An equipment port that is loop capable. Used to connect an equipment port to the
fabric in a loop configuration through the FL_Port on a switch.
There are 8, 16 or 32 physical ports on varying models of a Compaq
StorageWorks Fibre Channel SAN Switch; certain models constrain the type of
port the switch can support. Each port can be independently configured as one of
the following types.
22 Quickloop Fabric Assist User Guide
Using Quick Loop
■ F_Port—A fabric port that is not in loop mode. Able to transmit under fabric
protocol, and interface over links. N_Ports on equipment connect to F_Ports
on switches.
■ FL_Port—A fabric port on a switch that is in loop mode. Used to connect loop
capable NL_Ports to the switch in a loop configuration.
■ E_Port—Expansion port. A port is designated an E_Port when it is used as an
interswitch expansion port to connect to the E_Port of another switch, to build
a larger switch fabric, or to build a two-switch QuickLoop configuration.
Sometimes, a single fabric loop device is attached to a port. In this case, the
port would function as an FL_port. The attached device possesses either an
N_port (if the device is fabric-capable) or an NL_port, in which case the
device would be connected to the fabric in a loop configuration through an
FL_Port on a switch. In this latter case a looplet is created.
■ looplet—A set of devices connected in a loop to a port that is itself a member
of an arbitrated loop. By contrast, a single device rather than a loop might be
connected to a port.
Each device in a private loop must have a unique physical address. The
devices in a QuickLoop are assigned a unique phantom AL_PA.
■ AL_PA—Arbitrated loop physical address. A one-byte value used to identify
a device in an arbitrated loop.
During implementation and operation of switches in a QuickLoop, messages
are transmitted by devices as they come online. These messages, called Loop
Initialization primitives (LIPs), are in addition to normal data traffic.
Dual-switch QuickLoop
In a dual-switch QuickLoop, the initialization process is driven by one of the
switches, called the QuickLoop master. The role of the QuickLoop master is
dynamically assigned at each instance of QuickLoop initialization, according to
the following criteria:
■ If one switch receives LIPs from its looplets and the other does not, the switch
that receives the LIPs is the QuickLoop master.
■ If both switches receive LIPs from their respective looplets, the switch with
the lower domain ID is the QuickLoop master.
QuickLoop Initialization
QuickLoop initialization includes two passes:
23Quickloop Fabric Assist User Guide
Using Quick Loop
■ Pass 1: Sequential looplet initialization—Allows each device in a looplet to
obtain a unique AL_PA.
■ Pass 2: Full QuickLoop initialization—Brings QuickLoop up to operation.
Note: If Zoning is in use, the looplets that are initialized depend upon the zoning
configuration.
Pass 1: Sequential Looplet Initialization
This pass allows each device in the QuickLoop to obtain a unique AL_PA in a
single AL_PA bit-map. Only those looplets from which LIPs were received are
initialized, using the loop initialization procedure described in the FC-AL
standard. The AL_PAs of devices in looplets from which no LIPs are received are
preserved during initialization.
Pass 2: Full Initialization
This pass sets up the QuickLoop as a single logical PLDA. This is accomplished
by making all assigned AL_PAs addressable by any device in the QuickLoop,
regardless of whether the destination device and source device are in the same
physical looplet. If the destination and source devices are not in the same physical
looplet, the hidden FL_Port in the source device looplet acts on behalf of the
destination device, and the fabric provides the transport service.
Sample Configurations
The following examples illustrate possible configurations of one or two switches
to form a QuickLoop. For the details of setting these sample configurations using
telnet commands, refer to Fabric OS Reference Guide.
The QuickLoop configuration examples are:
■ Configuration 1: Emulating a Hub on page 25—A simple configuration in
which a QuickLoop-enabled switch is used as a hub emulator or concentrator.
■ Configuration 2: Dual-switch QuickLoop on page 26—A dual-switch
configuration in which two switches are cascaded by a local fiber connection
to make up a QuickLoop.
■ Configuration 3: Long Wave Laser Connection on page 27—A dual-switch
configuration in which two switches up to 10 kilometers apart are connected
to make up a QuickLoop.
24 Quickloop Fabric Assist User Guide
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