HP C737990900 User Manual

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the SCSI

interface

hp ultrium drives

technical reference manual

generation 2 SCSI and FC drives

volume 3: the SCSI interface

Part Number: C7379–90900 Volume 3

Edition 4, February 2003

Notice

The information contained in this document is subject to change without notice.

Hewlett-Packard makes no warranty of any kind with regard to this material, including, but not limited to, the implied warranties o f merchantability and fitness for a particular purpose. Hewlett-Packard

shall not be liable for errors contained herein or direct, indirect, special, incidental or consequential damages in connection with the furnishing, performance, or use of this document.

This document contains proprietary information which is protected by copyright. All rights reserved. No part of this document may be photocopied, reproduced or translated to another language without the prior written consent of Hewlett-Pack ard.

Revision History

Version Date Changes

Edition 1 Nov. 2000 All Edition 2 Mar. 2001 Addition of Read and Write attribute commands and Drive Error Codes Edition 3 May 2002 Inclusion of the Request Block Address command and the Control mode

page, together with numerous small changes

Edition 4 Feb 2003 Generation 2 SCSI and FC drive version

This document is frequently revised and updated. To find out if there is a later version, please ask your HP OEM Representative.

The Purpose of this Manual

This is one of five volumes that document HP Ultrium drives. This volume provides background information for driver and application developers. The following products are covered. Capacities are when the drive is using data compression with a compression ratio of 2:1, where applicable:

■ HP Ultrium Generation 2 Full-Height SCSI Internal Drive

■ HP Ultrium Generation 2 Full Height FC Internal Drive

Note Throughout this manual frequent reference is made to SCSI

commands. For more information on SCSI commands for HP Ultrium drives see volume 3, the SCSI Interface, of the HP Ultrium Technical Reference Manual. Ordering details are given below.

Interface Implementation

HP Ultrium drives use SCSI-3 as the interface to connect to the host system. This chapter gives an overview of how the interface operates.

Full details of the messages are given in Chapter 2 and of commands in

Chapter 3 and Chapter 4.

The SCSI Interface

The Small Computer Sy stem Interf ace (SCS I) is an industry standard , a ppr o v ed by the American National Standards Institute (ANSI). You are recommended to read the ANSI standard document in conjunction with this manual. The ANSI specification defines the interface in general while this document describes the HP Ultrium implementation.

The SCSI implementation provides a drive with a standard set of features and functions. These include the following:

■ Synchronous data transfers

■ Asynchronous data transfers

■ Implementation of all mandatory and most optional commands of the

Sequential Access command set

■ LVD (Low-Voltage differential) SCSI connection

■ Ultra3 wide SCSI

■ Conformance to the following SCSI standards:

— SAM-2 T10/1157-D rev.23 — SPI-3 ANSI NCITS.336:2000 — SPC-2 ANSI NCITS.351:2001 — SSC ANSI NCITS.335:2000

Interface Implem en ta tion 13

Supported Messages

The following messages are supported by the drives:

■ ABORT

■ BUS DEVICE RESET

■ COMMAND COMPLETE

■ DISCONNECT

■ IDENTIFY

■ IGNORE WIDE RESIDUE

■ INITIATOR DETECTED ERROR

■ MESSAGE PARITY ERROR

■ MESSAGE REJECT

■ NO-OP

■ RESTORE POINTERS

■ SAVE DATA POINTER

■ Extended Message: PARALLEL PRO TOCOL REQUEST

■

For implementation details on these messages, see Chapter 2, “Messages”

(no operation)

Extended Message: S YNCHRONOUS DATA TRANSFER REQUEST Extended Message: WIDE DATA TRANSFER REQUEST

Supported Commands

The following commands are supported by the drives. They include all Mandatory and Extended commands and most Optional commands.

19h 12h 1Bh 2Bh 4Ch 4Dh

15h/55h

1Ah/5Ah

1Eh 08h 05h

14 Interface Implementation

ERASE INQUIRY LOAD/UNLOAD LOCATE LOG SELECT LOG SENSE MODE SELECT MODE SENSE PREVENT/ALLOW MEDIUM REMOVAL READ READ BLOCK LIMITS

57h/17h

03h 44h

A0h

56h/16h

01h 1Dh 11h 00h 13h 0Ah

RELEASE UNIT REQUEST SENS E REPORT DENSITY SUPPORT REPORT LUNS RESERVE UNIT REWIND SEND DIAGNOSTIC SPACE TEST UNIT READY VERIFY WRITE

3Ch 34h 1Ch

READ BUFFER READ POSITION RECEIVE DIAGNOSTIC RESULTS

SCSI Features

Design Approach

Power-On

WRITE BUFFER

3Bh

WRITE FILEMARKS

10h

For implementation details on these commands, see Chapter 3, “Commands—

Introduction” and Chapter 4, “Commands”.

The features supported by the drive are based on standards, both official and de facto. The dr iv e is fully compliant w ith the SC SI-3 specif ication and supports all features required by that standard. However, since most tape drive support software has been written using the SCSI-2 standard, this document is based on SCSI- 2 and uses SCSI-2 terminology. Since SCSI-2 is virtually a compliant subset of SCSI-3, this is not inconsistent. However, where SCSI-3 makes an option in SCSI-2 a requirement, the SCSI-3 requirement is always used. Also, all required SCSI-3 extensions are supported by the drive.

Interface Implementation

Reset Strategy

Soft Resets On receiv ing a r e set through the Host Interf ace (S CS I or FC), the Host Interfac e

The drive will respond to TEST UNIT READY, INQUIRY, REPORT LUNS and

REQUEST SENSE commands within 5 seconds of power on. The first command

other than Inquiry or Request Sense from any initiator will get a

CONDITION

this, any medium access command will be reported with a sense key of

READY

Medium access commands will be reported with additional sense of 0401h (drive in process of becoming ready).

is returned to a known base state. If the reset command is received over the Automation Controller Interface serial port, the SCSI and ACI interfaces are returned to known bas e states . The baud r at e fo r the port will be r eturned to its

status with UNIT ATTENTION sense data for the power on. After

and additional sense of 3E00h (LUN has not self-configured yet).

Interface Implem en ta tion 15

CHECK

NOT

default setting. The know n base s tate is def ined in the S CS I-3 specifi cation and includes the following:

■ The current I/O process is aborted.

■ Any queued I/O processes from other initiators are removed.

■ All reservations are cleared.

■ All mode values are reset to their defaults.

■ Synchronous/Wide negotiations are cleared (SCSI drives only).

■ A UNIT ATTENTION condition is set.

■ Any buffered writes are flushed to tape.

■ The logical position is undefined.

Hard Resets The Reset button on the front panel and the ACI_RESET_L line on the

Abort Handling

The drive will be able to respond to

SENSE

and REPORT LUNS within 250 ms of the reset line being released. The

first command other than these from any initiator will get a

CONDITION

status with UNIT ATTENTION sense data for the reset. However,

TEST UNIT RE ADY, INQUIRY, REQUEST

CHECK

other commands may not be processed until the internal state of the drive has been reset. Any commands which cannot be processed will be accepted and queued until the drive is ready to process them.

Automation Controller Interface are both connected to the Power-Up Reset interrupt on the processor. The effect is equivalent to power-cycling the drive. The contents of the tape and cartridge memory may not be consistent after the action and any data in the drive buffer will be lost.

If an abort condition is detected before a command phase completes, the bus is set to bus free and the command is not executed.

If an abort condition is detected between the end of the command phase and the start of the status phase, then the bus is set to bus free and the processing below is carried out.

If an abort condition is detected during status phase, the bus is set to bus free. If a command, other than

TEST UNIT READY, INQUIRY and REQUEST SENSE, is

received after the abort but before the drive is ready to process the command, the drive will disconnect and wait until the abort processing has completed before executing the command. A

TEST UNIT READY command will report with

16 Interface Implementation

GOOD status immediately. A REQUEST SENSE command will give NO SENSE.

INQUIRY command will return the required data and give GOOD status.

Command Abort Processing

ERASE

INQUIRY LOAD/UNLOAD

LOCATE

LOG SEL ECT

LOG SENSE MODE SELECT

MODE SENSE PREVENT/ALLOW

MEDIUM REMOVAL READ

Long erase is aborted as quickly as possible without corrupting tape format. Short erase completes.

None Load completes and logically positions tape at BOT. Unload is aborted

leaving logical position at BOT unless operation is past the “point of no return” in which case the tape is ejected.

The logical position is set back to that at the start of the operation unless the operation is past its “point of no return”, in which case the operation completes.

If data transfer is complete, command is completed, otherwise, no action is taken

None If data transfer is complete, command is completed, otherwise, no action is

taken. None The command completes.

The current position is set to the first record boundary at or after the start of the current data burst.

Interface Implementation

READ BLOCK LIMITS READ BUFFER READ POSITION RECEIVE DIAGNOSTICS

RESULTS RELEASE UNIT

REQUEST SENSE

None None None None

The command completes. None

Interface Implem en ta tion 17

Command Abort Processing

RESERVE UNIT REWIND SEND DIAGNOST IC SPACE

The command completes. The command completes. Vendor Unique The logical position is set back to that at the start of the operation unless the

operation has passed its “point of no return”, in which case the operation completes.

TEST UNIT READY WRITE

None The data up to first record boundary in the current burst is written to tape.

Any subsequent data is discarded. If there is no record boundary in the current burst, the record is truncated to the amount of data transferred and written to tape.

WRITE BUFFER

If data transfer is complete, command is completed, otherwise, no action is taken.

WRITE FILEMARKS VERIFY

The command completes. The logical position is set to the next record boundary after the point where

the verify was aborted.

Bus Pari ty Errors (Parallel SCSI only)

On detecting a bus parity error during a Command or Data Out phase or receiv ing an Initiator det ected er r or mess age during a Dat a In or S tatus phase , the drive attempts t o r e try the bus phase. A Restor e Poin t er s me ssage is sen t t o the initiator and the transfer is repeated. Only one retry is attempted. If the retry fails or the restore pointers message is rejected, then the drive goes to status phase and attempts to report an initiator detected error message, t he dri ve goes t o bus fr ee . Th e sense ke y is set to error) or 4B00h (data phase error).

If an Initiator Detected Error or Message Parity Error message is received during Message In phase, the initiator has detected an error in the message. The dri v e will go to Messag e In and r esen d the mess age tha t was in err o r . If the subsequent message is rejected with an Initiator Detected Error, then the drive goes to Status phase and sends

18 Interface Implementation

CHECK CONDI T ION st atu s. If this f ails with

ABORTE D C O MMA ND w ith additional sense of 4A00h (command phase

CHECK CONDITION status. The sense k ey is set

to ABORTED COMMAND with additional sense of 4800h (Initiator Detected Error).

If the subsequent message is rejected with an Message Parity Error, then the driv e goes to Status phase and sends is set to

ABORTED COMMAND with additional sense of 4300h (message

error). On detecting a bus parity error during a Message Out phase, the drive will

handshake in all message bytes until ATN is deasserted. It will then stay in Message Out phase to indicate to the initiator that the whole Message Out phase should be resent.

Disconnect Strategy (Parallel SCSI only)

The disconnect strategy used by the drive is based on the assumption of maximizing bus utiliz atio n for large sequen tial data transf ers fr om a large data buffer. The drive will disconnect whenever it believes that it will provide better bus utilization. This may be between command and data phases, between bursts of data or before sending status. However, the drive will guarantee that it will send the configured maximum burst size or the remaining data in the transfer in any single data phase burst if the max imum burst size has been set to a value other than zero.

Multi-Ini t iator Support

CHECK CONDITION status. The sense key

Interface Implementation

All drives will support at least two initiators on the same bus. If more initiators are supported, all features are supported for the supported number of initiators.

The drive supports untagged queueing when operating with multiple initiators. If a command from one initiator is being processed when a command, other than

TEST UNIT READY, INQUIRY, REPORT LUNS and REQUEST SENSE, is

received from a second initiator, then the drive will disconnect and the new command is queued. Commands other than

these from different initiators are

always executed in strict order of receipt. If the queue is full or disconnect privilege is not granted in the new command, the drive will report

EST UNIT READY, INQUIRY, REPORT L UNS an d RE Q UE S T SENSE co mmand s ar e

BUSY status.

always processed immediately, irrespective of whether a command from another initiator is being processed.

The drive will maintain sense data for the supported number of initiato r s. If an additional initiator connects to the drive, the drive will erase all sense data for

Interface Implem en ta tion 19

the initiator that least recently connected before processing the command for the new initiator. See “Sense Data Management” on page 131 for more details.

Fibre Channel Operation

Note This applies only to Fibre Channel drives.

The following sections have information specific to Fibre Channel operation:

■ “Fibre Channel Logical Unit Control Mode Page” on page 86

■ “Fibre Channel Port Control Mode Page” on page 87

■ “Vital Product Data Pages” on page 49

Fibre Channel Addressing

Before describing HP’s implementation of Fibre Channel addressing, the concepts of Names and Addresses need to be clarified.

Names

Names are 64-bit identifiers assigned permanently to the tape drive during manufacture. They are commonly referred to as World Wide Names since they must be guaranteed unique. The names are typically used for identifying the device to operating systems, since addresses are assigned dynamically. There at least eight different name formats distinguished by the Network Address Authority (NAA). Only one is used on HP Ultrium drives. This is the IEEE Registered Name (NNA=5) and has the following format:

This name is made up of three fields:

■ NAA Identifier (4 bits). “5” indicates a IEEE Registered Name.

■ IEEE Company ID (24 bits). Assigned by IEEE to the company.

■ Vendor Specified ID (36 bits). Assigned by the company.

20 Interface Implementation

Addresses

Each Fibre Channel port also has a Port Address which is assigned during loop initialization and/or Fabric Login. This is a 24-bit value in the following format:

The AL_PA is the Arbitrated Loop Physical Address. This is normally assigned dynamically during loop initialization.

If the loop is not attached to a fabric (in other words, when it is private,) the top two bytes will be zero. If the loop is attached to a fabric, the tape drive is assigned the top two bytes when it logs into the fabric.

Together, the three bytes pr o vi de a unique addres s on the F ibr e Channel f abr ic that is used for frame addressing. It forms the equivalent of the Target ID or Initiator ID in SCSI.

HP’s Implementation of Names and Addresses

The HP implementation uses three adjacent IEEE Registered Names:

■ The first (last bits = 00) is used as the Port A World Wide Name.

■ The second (last bits = 01) is used as the Port B World Wide Name.

Interface Implementation

■ The third name (last bits = 10) is used for the Device World Wide Name.

(These are assigned during manufacture from HP’s pool of names, although only the first will actually be stored in the drive NV-RAM).

The port addresses will be assigned using the ‘standard’ AL_PA initialization mechanisms. The ‘Fibre Channel Port Control mode page’ controls this. The drive has the ability to support hard addresses as part of this scheme.

Interface Implem en ta tion 21

The values of the names can be obtained using the Device Identification Vital Product Information Page (part of the

INQUIRY command).

Implications for Libraries

■ Normally a standalone drive will operate using its own ‘hard’ names.

■ The drive kno ws it is in a library or other ‘managed’ environment since one

of the signal lines on the ACI (Automation Control Interface) will be tied down.

In this case, the dr iv e wi ll not go on the FC loop until it is t old to . The libr ary can optionally download a new, soft base name (Port A/Device Name) into the drive at this point. The drive will then use this as the origin of its names. The library manufacturer would be responsible for obtaining this IEEE Registered Name. It would be a property of the library, not the drive.

■ If the library wants to ‘warm swap’ drives, it can. It just ‘turns off’ the drive

with the soft name using the ACI and then turns on the spare drive, downloading the same name to it.

■ If a drive is r emo ved f rom th e library, it will not have the ACI signal tied low

and so will re v ert to its or iginal h ard name . It should f or get the s oft name in this case.

■ If the library controller breaks, the drive will time out the ACI interface in

~10 seconds. The drive still knows it is in a library since the ACI signal is

22 Interface Implementation

still tied low, so in this case it will use the soft name last downloaded. This will allow drive access without confusing the host.

Field Replaceable Units

An FRU code identifies which part of the hardware is considered to have failed. These codes turn up in sense data byte 14 and as the sense code qualifier for sense codes 4400h (internal target failure) and 40XX (diagnostic failure).

Althoug h the r e are no actual Field Replaceable Units on HP Ultrium dri ves, the following sub-assemblies can be replaced at Repair Centres:

■ Drive PCA ■ Head Assembly

■ Mechanism ■ Front Panel

Descriptions of Signals (Parallel SCSI only)

The SCSI interface consists of 2 7 signals—9 contr ol lines, 16 data lines and 2 parity lines. A description of these signals is given in the following table.

Interface Implementation

Signal Name Driven by Description

-BSY

-SEL

-C/D

-I/O

Busy — OR-tied signal used to indicate that the SCSI bus is in use. Select Initiator

Target

Control/Data Target Indicates whether control or data information is on the data

Input/Output Target Controls the direction of data movement on the bus with

Used to select a target during the Selection phase. Used to select an initiator during the Reselection phase.

bus.

True (low) Control information False (high) Data information

respect to the Initiator. This signal is also used to distinguish between Selection and Reselection phases.

Interface Implementation 23

Signal Name Driven by Description

True (low) Input to the initiator False (high) Output from the initiator

-MSG

Message Target Indicates a Message phase on the bus.

True (low) Message phase False (high) Command, Data or Status phases

-REQ

-ACK

Request Target Indicates a request for a REQ/ACK data transfer handshake. Acknowledge Initiator Indicates an acknowledgment for a REQ/ACK data transfer

handshake.

-ATN

Attention Initiator Indicates that the initiator has a message to send to the

target.

-RST

Reset — OR-tied signal that is used to indicate a Reset condition.

DB(15-0) Data Bus — 16 data-bit signals that, with the parity-bit signal, form the

data bus. DB15 is the most significant bit , and has the highest priority during the Arbitration phase.

DB(P1-P0) Data Bus — Data parity bits that ar e s et t o odd, but are jumper-selectable

options. There are two discrete parity bits, one for the lower 8 data bits, the other for the upper 8 bits. Parity is not valid during the Arbitration phase.

24 Interface Implementation

Messages

This chapter includes all SCSI messages, both supported and unsupported. Parts of this chapter come from Section 5, Logical Characteristics, of the SCSI standards (see page 13).

The message system provides an initiator and a target on the SCSI bus with a means of managing communication. The available messages are listed in this chapter.

Message Out Support (Parallel SCSI only)

Name Code Support

Abort 06h An abort condition is generated (see “Abort Handling” on page 16). Bus Device Reset 0Ch A reset condition is generated (see “Reset Strategy” on page 15). Extended Message 01h See “Extended Message Support” below. Identify 80h+ The Identify Out message is sent by the initiator to identify the Logical Unit

to be accessed and to set Disconnect Privilege.

Initiator Detected Error

05h The initiator has detected an error in the data being sent in a Command,

Data or Status phase. The drive will send a restore data pointers message to retry the data transfer. (See “Message In Support (Parallel SCSI only)” below for details).

If the message is received immediately after an Identify message or after the Command Complete message has been sent, the drive will go Bus Free.

Messages 25

Name Code Support

Message Parity Error

Message Reject 07h This message is sent when the initiator does not support a message sent b y

No Operation 08h This message has no effect and is ignored.

09h The initiator has detected a parity error in a message. The drive will retry

the message. (See ““Message In Support (Parallel SCSI only)” below for details).

If the message is received immediately after an Identify message or after the Command Complete message has been sent, the drive will go Bus Free.

the drive or that the message is inappropriate. If the message being rejected is Disconnect, Synchronous Data Transfer Request or Wide Data Transfer Request, the operation continues without those features. For all other messages, the message is treated as an Abort message.

If the message is received during a Command, Data or Status phase, immediately after an Identify message or after the Command Complete message has been sent, the drive will go Bus Free.

Message In Support (Parallel SCSI only)

Name Code Support

Command Complete 00h This message is sent by the drive at the end of the status phase to

indicate that a command is complete. Once the message is sent, the drive releases the bus and goes to Bus Free.

Disconnect 04h This message is sent by the driv e to indicate that it is about to disconnect

from the bus and go to Bus Free. During a Data phase, it is always preceded by a Save Data P o inter s message. If a Message Rej ect message is received in response to this message, then the disconnect is prevented.

Extended Message 01h See “Extended Message Support” below. Identify 8Xh The Identify In message is sent to the initiator during reconnect to

indicate which Logical Unit is reconnecting.

26 Messages

Name Code Support

Ignore Wide Residue

23h This message is sent by the drive to the host to indicate that a byte on a

wide bus is not valid. This is supported whenever a wide transfer is acti ve. It should be sent at

the end of the data phase. The standard action of the drive is to send this message between the data phase and the status phase with no disconnect.

Message Reject 07h This message is sent to the initiator when the message received by the

drive is unsupported or inappropriate.

Restore Pointers 03h This message causes the initiator to reset its data transfer pointers to the

values they held when the last save data pointers message was sent. It will be sent when a parity error is detected on the bus or when an Initiator Detected Error message is received in order to retry the data phase.

Save Data Pointers 02h This message instructs the initiator to save its current data transfer

pointers for use with a subsequent Restore pointers message. This message will always be sent before a Disconnect message during data phases.

Extended Message Support

Name Code Support

Messages

Synchronous Data Transfer Request

01h The drive will never initiate a Synchronous data transfer negotiation, but

will expect the initiator to do so. If the message is received after selection and befor e the command phase,

it will then go to message-in phase and respond with a valid r esponse to complete the negotiation.

Wide Data Transfer 03h The drive will never initiate a Wide data transfer negotiation but will

expect the initiator to do so. If the message is received after selection and befor e the command phase,

it will then go to message-in phase and respond with a valid r esponse to complete the negotiation.

Note that SDTR negotiated parameter s will become asynchr onou s after a WDTR.

Messages 27

Name Code Support

Parallel Protocol Request

04h The drive will never initiate a Parallel Protocol Request transfer

negotiation but will expect the initiator to do so. If the message is received after selection and befor e the command phase,

it will then go to message-in phase and respond with a valid r esponse to complete the negotiation.

Synchronous Data Transfer Request

7 6 5 4 3 2 1 0 0 1 2 3 4

Extended Message (01h)

Extended Message Length (03h)

SDTR (01h)

Transfer Period Factor

Req/Ack Offset

Wide Data Transfer Request

7 6 5 4 3 2 1 0 0 1 2 3

Extended Message (01h)

Extended Message Length (02h)

WDTR (01h)

Transfer Width Exponent

28 Messages

Parallel Protocol Request

7 6 5 4 3 2 1 0 0 1 2 3 4

Extended Message (01h)

Extended Message Length (06h)

Parallel Protocol Request (04h)

Transfer Period Factor

Reserved (0)

7 6 5 4 3 2 1 0 5 6 7

Reserved (0) QAS_Req DT_Req IU_Req

Req/Ack Offset

Transfer Width Exponent

Fields:

Transfer Period Factor

09h Transfer period of 12.5s (FAST-80). Only valid when DT transfers have been

requested 0Ch Transfer period of 50s (FAST-20) — LVD/SE drives only 19h Transfer period of 100s (FAST-10) 32h Transfer period of 200s (FAST-5)

Req/Ack Offset This has a maximum value of 255. Transfer Width

Exponent

For ST transfers, this can be either 0 (Narrow) or 1 (Wide). For DT transfers, it must be set to 1.

QAS_Req 0 This bit will be ignored and the drive will always return zero. DT_Req This bit determines whether DT mode has been requested, in other words, packetized

data transfers.

IU-Req 0 This bit will be ignored and the drive will always return zero.

Status

A Status byte is sent from the drive to the host during the Status phase at the end of each command as specified in the SCSI specification, unless the command has been cleared by an message, or by a hard reset.

ABORT message, by a BUS DEVICE RESET

Messages

The Status bytes that the drive returns are as follows:

00h GOOD: This status indicates that the drive has successfully completed the command. 02h CHECK CONDITION: Any er r o r, exception, or abnor mal condition that causes sense data

to be set returns

CHECK CONDITION. The REQUEST SENSE command should be sent

following this status to determine the nature of the error.

04h CONDITION MET: This status will never be returned by an HP Ultrium tape drive.

Messages 29

08h BUSY: The drive is unable to execute the command at this time. Try again later. The drive

tries to avoid using this status code during normal operation. It can sometimes be used after commands have been aborted, during power-on and if there are multiple selecting

initiators. 10h INTERMEDIATE: This status will never be returned by an HP Ultrium tape drive. 14h INTERMEDIATE CND: This status will never be returned by an HP Ultrium tape drive. 18h RESERVATION CONFLICT: Returned if the drive is reserved by another party. See the

Reservation check. 22h COMAND TERMINATED: This status will never be returned by an HP Ultrium tape drive. 28h QUEUE FULL: This status can be returned by an HP Ultrium FC drive but will never be

returned by a SCSI tape drive.

30 Messages

Commands—Introduction

This chapter contains general notes relating to the SCSI commands listed in

Chapter 4.

Summary

The following table is a summary of the SCSI commands for sequential access devices, showing the operation code:

Opcode

(hex)

00 01 03 05 08 0A 10 11 12 13 15 16 17 19 1A 1B 1C 1D

Command Name

TEST UNIT READY REWIND REQUEST SENSE READ BLOCK LIMITS READ WRITE WRITE FILEMARKS SPACE INQUIRY VERIFY MODE SELECT RESERVE UNIT RELEASE UNIT ERASE MODE SENSE LOAD/UNLOAD RECEIVE DIAG RESULTS SEND DIAGNOSTIC

Opcode

(hex)

1E 2B 34 3B 3C 44 4C 4D 55 56 57

8C 8D

Command Name

PREVENT MEDIUM REMOVAL LOCATE READ POSITION WRITE BUFFER READ BUFFER REPORT DENSITY SUPPORT LOG SELECT LOG SENSE MODE SELECT (10) RESERVE UNIT (10) RELEASE UNIT (10) MODE SENSE (10) READ ATTRIBUTE WRITE ATTRIBUTE REPORT LUNS

Commands—Introduction 31

Command Details

The command descriptions in this section are listed in alphabetical order of command name. Each command is described briefly. This is followed by a list of pre-execution checks which are described below. The Command Descriptor Block (CDB) is then given, with details of the various parameter bits and fields.

Pre-Execution Checks

Note In compliance with the SCSI specification, the drive terminates a

command with a key to is received which is not zero.

Before executing a command, the drive makes a number of checks. They fall into three categories:

■ Checks on the command sent by the host. T hese ensure that no rese rved or

fixed fields have been set to illegal values. They check the syntax of commands, in other words the cross dependency of fields. F or ex ample, the Flag bit must not be set if the Link bit is not set.

■ Checks to ensure that there are no outstanding UNIT ATTENTION or

DEFERRED ERROR events posted for the host that has sent the command.

CHECK CONDITION status and sets the sense

ILLEGAL REQUEST when a reserved bit, byte, field or code

■ Checks on media access abilities. These are performed for commands

The checks are described below in alphabetical order. The usual order of execution is Illegal Field, Fixed Bit, Flag Link, Bad LUN, Reservation, Deferred Error, Unit Attention, Media Access, Media W r ite , Diagnosti c Statu s, Humidity , Parameter List.

Bad LUN Check

For all commands except INQUIRY 12h, this checks that the LUN specified by the host is zero. The LUN is taken from the lowest 5 bits of the host’s message.

32 Commands—Introduction

requiring access to the cartridge. A command is rejected if it attempts to access the cartridge when no cartridge is present or the cartridge is unloaded.

IDENTIFY

■ If no IDENTIFY message is supplied, the LUN is taken from the host’s

■ If an IDENTIFY message is supplied, the LUN in the host’s Command

■ If the LUN is unsupported, and the host command is not REQUEST SENSE,

■ If the LUN is unsupported, and the host command is REQUEST SENSE, the

Deferred Error Check

A deferred error is generated when a command with immediate report fails after the report has been returned. The check looks to see if a deferred error exists f or the host whic h sent the command, in othe r words , a deferr ed err or fo r which exists, then the drive reports command is set to previous command failed).

Note that if a both exist for an initiator, the This is because the operation leading to the deferred error must have been older than that leading to the unit attention. The drive reports the conditions in the order in which they arose.

Command Descriptor Block.

Descriptor Block is ignored

CHECK CONDITION is reported to the host with a sense key of ILLEGAL REQUEST

original sense data is replaced with a sense key of

, and additional sense of 2500h (logical unit not supported).

ILLEGAL REQ UEST, and

additional sense of 2500h (logical unit not supported). This new sense data is returned to the host. Once the command has completed successfully, the sense data is cleared.

CHECK CONDITION status has not yet b een reported. If such an error

CHECK CONDITION. The sense data for the

DEFERRED ERROR (which was generated when some

UNIT ATTENTION condition and a DEFERRED ERROR condition

DEFERRED ERROR condition will be reported first.

Diagnostic Status Check

This ensures that the drive is in a fit state to access the media. It does this by checking that there is no

If the drive has failed diagnostics, key of on component X).

Commands—Introduction

DIAGNOSTI C FAIL status within the drive.

CHECK CONDI TION i s r e port ed w ith a se nse

HARDWARE ERROR and additional sense of 400Xh (diagnostic failure

Commands—Introduction 33

Fixed Bit Check

For the READ, VERIFY and WRITE commands, a Fixed bit set to 1 indicates that the length parameter of the command is for fixed block mode. If fixed block mode is selected then the block size in the Mode Select block descriptor must not be zero. Otherwise set as described for the

Flag Link Check

This check ensur es tha t the host ha s not se t the F lag b it in the contr ol b yte o f the command without setting the Link bit as well. If the test fails then

CONDITION

sense of 2400h (invalid field in CDB). The Flag field is identified as the bad field.

Illegal Command Check

If the drive does not recognize the opcode of the command that it has been sent, it will do one of the following:

■ Report CHECK CONDITION status. The sense key will be set to ILLEGAL

REQUEST

command opcode).

■ Report an invali d f i eld in the command descriptor block. The sense key will

be set to (invalid field in CDB) and the field pointer in the sense data will be zero.

CHECK CONDITION is reported and the sense data is

ILLEGAL FIELD check.

CHECK

is reported with a sense key of ILLEGAL REQUEST and additional

and the additional sense code will be set to 2000h (invalid

ILLEGAL REQUEST, the additional sense code will be set to 2400h

Illegal Field/Request Check

Checks are performed to ensure the host has not set any of the following in the command descriptor block:

■ a fixed field

■ a reserved field

■ the control field

■ two or more fields to logically conflicting values

If a field has been set to an illegal value:

■ CHECK CONDITION status is reported to the host with a sense key of

ILLEGAL REQUEST and additional sense of 2400h “invalid field in CDB”.

34 Commands—Introduction

■ The sense key specific bit is set and the sense key specific bytes will be a

■ The command/data bit is set, indicating that the illegal parameter was in

Note Command descriptor blocks ar e scanned from left (bit 7) to right

Media Access Check

This checks if the drive is able to perform media access commands. If the media is inaccessible then key of associated with the

field pointer.

the command.

(bit 0), and down (from byte 0 to byte n). The field pointer will be set to point to the first bit of the first illegal field encountered using this scanning route. In some cases, where multiple fixed fields are conti guous, th e fi eld pointer mi ght be set to poin t to the first bit o f the first fixed fi el d in the group of fixed fie lds , w he reas the actual illegality may lie in a later bit.

CHECK CONDITION status is reported with a sense

NOT READY. The additional sense will be set to one of the codes

NOT READY key.

Commands—Introduction 35

Commands—Introduction

Media Information Check

Durin g po w er-on and fol lo w in g a S CS I r e set , kno w ledg e o f the w he r eabo ut s of the cartridge is unavailable. It is not possible to execute commands which assume that this knowledge is available until the drive has recovered from the power-on or reset.

The test checks whether the drive knows if a cartridge is physically present in the drive.

If information about the tape cartridge is not available, the test fails with

CHECK CO NDIT ION, a sens e ke y o f NOT READ Y, and additional sense of 3E00

(logical unit has not self-configured yet).

36 Commands—Introduction

Media Write Check

This checks whether the media is write-pr otected . If it is, CHE CK CONDI TION is reported with a sense key of (write-protected).

Parameter List Check

For LOG SELECT, MODE SELECT and some diagnostic commands, the associated data sent to the drive is in the form of parameter lists. These are described under the command names in the next chapter. Checks are performed to test the following:

■ Fixed and reserved fields have not been modified. Fixed fields are

■ A field has been set to an invalid value.

■ The syntax of the page of parameters has been violated—for example,

DATA PROTECT and additional sense of 2700h

indicated by a number in round brackets following the field name.

wher e a p art ic ul ar v alu e in on e f i el d i mpo s es li mit ati ons o n t he v a li d range for another field.

Reser vation Check

If a field has been set to an illegal value, host with a sense key of (invalid field in parameter list).

The drive scans the data in the Command Description Block from “left” (bit 7) to “right”, and “down” (from byte 0 to byte n). It sets the field pointers to the first bit of the first bad field encountered. If the bad field is contained in a contiguous group of fixed fields, the pointers indicate the first bit of the first field in the group, even though the error may be in a later field in the group.

Note With

parameter list before acting on an y par amete r s, so all the mode parameters need to be correct before any of them are implemented.

This chec ks t o see if t he dr i ve h as been reserved for u se b y a h ost , an d if it h as, whether the host is the same host that sent the command being executed.

If the drive has been reserved for some other host then status is reported.

See the

RESERVE UNIT (page 141) and RELEASE UNIT (page 121) commands.

ILLEGAL REQUEST and additional sense of 2600h

Mode Select, the drive checks the integrity of the whole

CHECK CONDITION is reported to the

RESERVAT IO N C ONFLIC T

Commands—Introduction

Commands—Introduction 37

Unit Attention Check

This checks if a UNIT ATTENTION condition exists for the host which sent the command. If it does, the drive reports key of

UNIT ATTENTION. The remaining sense data will be set according to the

unit attention condition which exists. See Unit Attention Sense in the description of the

REQUEST SENSE command on page 132.

Command Descriptor Block

A SCSI command descriptor block (CDB) is a sequence of 6, 10, 12 or 16 bytes sent by a host to a SCSI target with the bus in command phase. The CDB tells the drive what action should be perfor med . The f inal byt e is know n as the

Control byte.

7 6 5 4 3 2 1 0

0 Group Code Operation Code 1 Reserved (0)

CHECK CONDITION status with a sense

2 (MSB)

-1 (LSB) n Vendor Unique (0)

There are a number of fields in a CDB which are common to all commands. These are shown in the following table.

Group Code Operation Code

and

The operation code uniquely identifies the command. The top three bits of the operation code are known as the group code and these define the length of the command descriptor block:

Group 0 Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7

38 Commands—Introduction

Six-byte commands Ten-byte commands Ten-byte commands Six-byte commands Sixteen-byte commands Twelve-byte commands not supported not supported

Multi-Byte Parameter

Reserved (0)

NACA(0) Flag (0) Link (0)

Reserved A reserved field should always be set to zero. The drive checks reserved fields, and if one is

Multi-Byte Parameter

non-zero then it will reject the command with A multi-byte parameter field in a co mm and is “big-endian”, that is, bit 7 of the first byte of this

field is the most significant.

CHECK CONDITION.

Control The control field i s mainly c oncerne d with the u se of link ed comm ands. Thes e are not support ed

by the LTO SCSI Command Set, so a CHECK CONDITION will be generated if this field is set to anything other than zero.

Vendor-Unique This field is ignored by the firmware NACA 0 The Normal ACA flag is 0, indicating that it is not supported. Flag 0 Link 0 Linked commands are not supported.

Commands—Introduction 39

Commands—Introduction

40 Commands—Introduction

Commands

This chapter describes all SCSI commands. Parts of the chapter are based on sections of the SCSI specification (see page 13).

For general notes on the command descriptions, see Chapter 3.

Commands 41

ERASE 19h

The ERASE command is used to erase data on tape from the current logical position. The Long bit is used to decide whether the ‘old’ data is physically overwritten or not.

Pre-Execution Checks:

Illegal Field Reservation Deferred Error Unit Attention Media Access Media Write Diagnostic Status

Command Descriptor Block:

7 6 5 4 3 2 1 0 0 1 2 3 4 5

Operation Code (19h)

Reserved (0) Immed Long

Reserved (0) Reserved (0) Reserved (0)

Control

CDB Fields:

Immed 0 The drive reports st atus after the command h as completed.

1 The drive reports status when it starts the command (after any pre-

execution checks and prerequisite unloads have completed).

Long The Long bit controls the distance to be erased.

0 The current position becomes the end of logical data. 1 End of Data is written, followed b y Data Set Separators to the end of the

tape.

Note The only use for short erase is to truncate data at current logical

position. It cannot be used to create a “hole” in the tape into which data can subsequently be written “in place”. This will merely cause the drive to streamfail. The logical tape position is unaffected by this command. A

CHECK CONDITION for Early

42 Commands

Warning EOM (drive error code 2C98h) will only be given if the tape was logically positioned past EOT immediately prior to this command.

Erase Specific Status:

Event Status Key Additional Sense

The erase fail s CHECK CONDITION HARDWARE ERROR 5100h (era se failure)

Commands

Commands 43

INQUIRY 12h

INQUIRY tells the drive to return information about the basic operating parameters to the host . These par ameters cannot be changed. T he driv e re turns Inquiry data to the host in a data-in phase.

Note This command is immune from most of the pre-execution checks

that other commands must pass (for ex am ple , it can be execut ed while the unit is reserved for another host). U

deferred error conditions are preserved and reported on

subsequent commands.

Pre-Execution Checks:

Only the Illegal Field Check is performed before the command is executed.

nit attention and

If the EVP D bit is clear, the page code must b e zero, otherwis e reported.

If the EVPD b i t i s s e t, the page code must be on e o f t h e su p po r te d p a ge cod e s for Inquiry data. Otherwise

Command Descriptor Block:

7 6 5 4 3 2 1 0 0 1 2 3 4 5

LUN Reserved (0) EVPD

CDB Fields:

LUN This field is ignored. EVPD Enable Vital Product Data

01Normal inquiry data is returned.

A page of vital product data is returned.

illegal request is

illegal request is reported.

Operation Code (12h)

Page Code

Reserved (0)

Allocation Length

Control

44 Commands

Page Code If the EVPD bit is zero the Page Code field must be zero.

If the EVPD bit is set to 1, the drive returns the Inquiry page in this Page Code field:

00h

Supported Vital Product Pages page

80h

Unit Serial Number page

83h

Device Identification page

C0h

Firmware Revision Levels page

C1h

Hardware Revision Levels page

C2h

PCA Revision Level s page

C3h

Mechanism Revision Levels page

C4h

Head Assembly Revision Levels page

C5h

ACI page

C6h

ARM Firmware Revision Levels page

C7h

HI Glue Logic Levels page—Fibre Channel only

Allocation Length

The maximum amount of data (in bytes) that should be returned. If more than this is available, the amount returned is truncated to allocation length. No error is reported.

INQUIRY Data Pages

Returned Data:

INQUIRY returns its standard data if the EVPD bit is zero, or returns a page of data as specified by the Page Code field when EVPD is one.

Commands

Standard Inquiry Data Format (LUN0)

This is the data returned by the drive in response to an Inquiry command with its EVPD bit set to zero . The data also depends on the value of the LUN field in the Inquiry CDB, the LUN value in the identify message and the configuration of the drive.

Note that the data below is for the standard distribution firmware.

7 6 5 4 3 2 1 0

Peripheral Qualifier (000b) Peripheral Device Type (01h)

RMB (1) Reserved (0)

2 3

AERC (0) Obsolete NACA(0) HiSup(0) Response Data Format (2)

Version Number (3)

Additional L e n gt h (5Bh)

Commands 45

7 6 5 4 3 2 1 0 5 6

BQue(0) EncSvr(0) VS(0) MultiP MChngr Obsolete Obsolete Adr16

RelAdr(0) Obsolete WBus16 Sync Linked(0) TranDis(0) CmdQue(0) VS(0)

(MSB)

15 16

(MSB)

31 32

(MSB)

35 36

(MSB)

55 56 57 58 59

72 73

(MSB)

Reserved (0) Clocking QAS (0) IUS (0)

Reserved (0)

Vendor Identification

(“HP “)

Product Identification

Product Revision Level

Reserved (0)

Version Descriptor 1

- - - - - - - -

Version Descriptor 8

Reserved (0)

(LSB)

46 Commands

The Standard Inquiry Data is based on the SCSI 3 standard for Standard Inquiry Data.

For the LUN to which the drive is attached, the Peripheral Qualifier field is set to 000b, the P er ipher al Dev i ce Type field is set to 01h, the Remova ble Medium (RMB) flag is set to 1 and the Device-type modifier is set to 0.

Inquiry Data Fields

Peripheral Qua lifier 000b

There is a device on the logical unit selected, so the LUN field in the identify message was 0.

011b

The LUN field in the identify message has specified an unsupported logical unit. This means any LUN other than 0.

Peripheral Dev i ce Type

01h

Sequential Access Device

08h

Medium Changer Device

1Fh

No Device (the Peripheral Qual ifier will be 011b in this case)

RMB 1 The Removable Medium bit is one, indicating that the tape can be removed. Device-Type Modifier 0 This is a six-bit user defined code, set to zero. Version Number 3 The Version Number is always set to 3, indicating that the drive complies to

ANSI X3.301:1997

AERC 0 This field is zero, indicating that Asynchronous Event Reporting Capability is not

supported.

NACA 0 The Normal ACA flag is 0, indicating that it is not supported. HiSup 0 The Hierarchical Support flag is 0, indicating that the hierarchical addressing

model is not supported.

Response Data Format

2 This field has the value 2, indica ting that the Inq uiry Data format compl ies with the

ANSI version of SCSI-2.

Additional Length The length in bytes of the length of the rest of the Inquiry data.

5Bh There are 91 (5Bh) more bytes of Inquiry data.

BQue Basic Queuing flag

0 The flag is zero for SCSI drives. Together with the CmdQue flag being zero this

indicates that the device does not support tagged tasks for this logical unit.

1 The flag is 1 for Fibre Channel drive, indicating the basic queuing is supported.

Commands

EncSvr The Enclosure Services flag is zero to indicate that the tape drive does not support

Enclosure Services command.

MultiP 0 The drive has a single port and does not implement multi-port requirements.

1 The drives has multiple ports.

MChngr The Medium Changer bit:

01The drive is not embedded within or attached to a medium transport element.

The drive is embedded wit h in or att ac hed to a medium transport elem en t .

Adr16 The 16-Bit Address flag is set according to whether the hardware supports this bus

feature. The flag is only valid for parallel SCSI and is clear for all other low level interfaces.

RelAdr 0 Relative Addressing is not supported.

Commands 47

WBus16 The Wide Bus 16 flag is set according to whether the hardware supports this bus feature.

The flag is only valid for parallel SCSI and is clear for all oth e r low level interfaces.

Sync 0 Synchronous data transfer is not supported. The flag should be zero for all low-

level interfaces apart from parallel SCSI.

1 Synchronous data transfer is supported. The flag is only valid for parallel SCSI.

Linked 0 The device does not support linked commands. CmdQue 0 The CmdQue flag is always zero. If the Basic Queuing (BQue) flag is also zero, this

indicates that the device does not support tagged tasks for this logical unit.

Vendor Identification

Product Iden tification A left-justified, vendor-specific, 16-byte string field of ASCII characters with space

Product Revision Level A vendor-specific string of four ASCII characters: “CYMV”:

Clocking 0For FC drives.

A vendor-specific, 8-byte string of ASCII characters, left justified and padded with space characters “HP”.

character padding on the right. The string consists of two parts:

■ First half (bytes 16–23): “Ultrium”

■ Second half (bytes 24–31): “<generation>-<interface type>”

■ The following strings have been defined:

■ Generation 2 FC drive: “Ultrium 2-SCSI” (“SCSI” is not a typo!)

■ Generation 2 SCSI drive: “Ultrium 2-SCSI”

■ C is the codename (F for a full-height drive)

■ Y is the year code . “0” is 2000, “1” is 2001, up to “9” for 2009. Alpha character s are

then used if needed.

■ M is the month code. “1” is January up to “B” for December.

■ V is an ASCII character representing the OEM variant of the code. “D” is the standard

distribution variant.

3 For SCSI drives, indicating that the drive supports both ST and DT transfers.

48 Commands

Version Descriptor These fields can be used to identif y up to eight stand ards t o whi ch the d riv e con form s. The

values supported are listed below. For SCSI drives, it is recommended that the first version descriptor is used for the SCSI architecture standard, followed by the physical standard, if any, followed by the SCSI protocol, followed by the appropriate SPC versio n , fo ll owe d by the device type command set, followed by the secondary command set, if any. The following are the SCSI version descriptors:

Value Standard

0054h

0B1Ch

0227h

021Ch

5–8

The following are the FC version descriptors:

0000h

Value Standard

0054h

0917h

0D7Ch

0DA0h

131Bh

1320h

0277h

021Ch

SAM-2 T10/1157-D rev 23 SPI-3 ANSI NCITS.336:2000 SPC-2 ANSI NCITS.351:2001 SSC ANSI NCITS.335:2000 not used

SAM-2 T10/1157-D rev 23 FCP-2 ANSI NCITS.332:1999 FC-AL-2 ANSI NCITS.350:200x FC-FS (no version claimed) FC-Tape T11/1315 revision 1.17 FC-FLA (no version claimed) SPC-2 ANSI NCITS.351:2001 SSC ANSI NCITS.335:2000

Commands

Vendor Specific data may be sent after the Product Revision Level.

Vital Product Data Pages

The following tables describe the vital product data pages. These pages are returned by the appropriate Page Code is set in the Command Descriptor Block. They contain vendor-specific produ ct information.

Supported Vital Product Data Pages Page

This is the data returned by the drive in response to an Inquiry command with its EVPD bit set to one and its Page Code field set to 0.

INQUIRY command when the EVPD bit is set and the

Commands 49

This page contains a list of all the VPD page-codes supported by the drive.

7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9

10 11 12 13 14

Peripheral Qualifier (0) Peripheral Device Type (1)

Unit Serial Number Page

The Unit Serial Number Page contains a single value which is a 10-byte ASCII string. The string, with the Vendor Identification and Product Identification fields in the standard Inquiry data, uniquely identifies the drive.

Page Code (00h)

Reserved (0)

Page Length (0Ah for SCSI drives, 0Bh for FC drives)

Supported Pages Code (00h) Unit Serial Number Page (80h) Device Identification Page(83h)

Firmware Revision Levels Page (C0h)

Hardware Revision Leve ls Page (C1h)

PCA Revision Levels Page (C2h)

Mechanism Revision Levels Page (C 3h)

Head Assembly Revision Levels Page (C4h)

Auto-Changer Interface Revision Levels Page (C5h)

ARM Firmware Revision Levels page (C6h)

HI Glue Logic Levels page (C7h)—Fibre Channel only

50 Commands

7 6 5 4 3 2 1 0 0 1 2 3 4

Peripheral Qualifier (0) Peripheral Device Type (1)

Page Code (80h)

Reserved (0)

Page Length (0Ah)

(MSB)

Serial Number

(LSB)

Device Identification Page

The Device Identification page contains information that identifies the tape drive uniq uely. For SCSI, a combinati on of the Vendor ID and Serial Number is

Commands

returned. For Fibre Channel, the Port and Device Names are returned as well.

7 6 5 4 3 2 1 0 0 1 2 3 4 n

Peripheral Qualifier (0) Peripheral Device Type (1)

Page Code (83h)

Reserved (0)

Page Length (n

(MSB)

Identification Descriptors

-3)

(LSB)

Identification Descriptors are constructed as follows:

7 6 5 4 3 2 1 0 0 1 2 3 4

(MSB)

Reserved (0) Code Set Reserved (0) Identifier Type

Reserved (0)

Identifier Length (n-3)

Identifier

(LSB)

Code Set 1 The Identification Descriptor is a binary field.

2 The Identification Descriptor contains only ASCII data.

Identifier Type 1 Vendor ID followed by th e produc t identification field f rom the s tandard in quiry data an d the

serial number field from the Serial Number Inquiry Page.

3 All devices with a Fibre Channel interface support an Identifier type of 3. In this case the

Identification Descriptor is the Fibre Channel 64-bit Name Identifier.

Defined Ide nti fiers

The following identifi ers will be returned in the given or der. What Port Name is returned depends on which port the Inquiry is sent to.

Commands 51

Device Serial Number (FC and SCSI)

7 6 5 4 3 2 1 0

11 12 27 28 37

0 1 2 3 4

(MSB)

Reserved (0) Code Set ( 2 ) Reserved (0) Identifier Type (1)

Reserved (0)

Identifier Length (34)

Vendor ID

(LSB)

Product Identification

(LSB)

Serial Number

(LSB)

Port Name (FC only)

7 6 5 4 3 2 1 0 0 1 2 3 4

(MSB)

Reserved (0) Code Set (1) Reserved (0) Iden ti fier Type (3)

Reserved (0)

Identifier Length (8)

Port Name

(IEEE Registered Name)

(LSB)

52 Commands

Device Name (FC only)

7 6 5 4 3 2 1 0 0 1 2 3 4

(MSB)

Reserved (0) Code Set (1) Reserved (0) Iden ti fier Type (3)

Reserved (0)

Identifier Length (8)

Device Nam e

(IEEE Registered Name)

(LSB)

Port Identifier (FC only)

0 1 2 3 4 7

0 1 2 3 4

7 6 5 4 3 2 1 0

Reserved (0) Code Set (1) Reserved (0) Identi fier Type (4)

Reserved (0)

Identifier Length (4)

(MSB)

Port Identifier

(LSB)

The Po rt Identifier will be set to 1 if the addressed port is port A, and set to 2 if the addressed port is Port B.

SCSI Type 3 Identifier (SCSI only)

7 6 5 4 3 2 1 0

Reserved (0) Code Set (1) Reserved (0) Iden ti fier Type (3)

Reserved (0)

Identifier Length (8)

(MSB)

SCSI Identifier

(IEEE Registered Name)

(LSB)

Commands

Driv e Component Revi sion Levels Pages

7 6 5 4 3 2 1 0 0 1 2 3 4

Peripheral Qualifier (0) Peripheral Device Type (1)

Page Length (5Ch)

(MSB)

Component (“CCCCCCCCCCCC”)

Page Code

Reserved (0)

(LSB)

Commands 53

30 48 49 72 73 95

7 6 5 4 3 2 1 0

(MSB)

Version (“RRR.VVV”)

(LSB)

(MSB)

Date (“YYYY/MM/DD hh:mm”)

(LSB)

(MSB)

Variant (“XXXXXXXXXXXX”)

(LSB)

The Drive Component Revision Levels pages contain details of the revisions of each of the major sub assemblies of the drive. For any given product, if these pages are the same then the drive has been built with the same components and with the same manufacturing process.

Each entry is a null-terminated ASCII string.

Page Code Page Code Component Name

C0h - Firmware C1h - Hardware C2h - PCA C3h - Mechanism C4h - Head Assembly C5h - ACI C6h - ARM C7h - HI Glue Logic

Component A 12-character entry to identify the component that the revision is for. Version A 7-character version code with a three- dig i t major revision number, a

period and a three-digit minor version num ber .

Date The date of the version. Variant An identifier indicating what version of the product this is.

8000 0100h 8002 0100h

“HI Glue Logic” (FC only)

Generation 2 full-height SCSI Generation 2 full-height FC

“Firmware” “Hardware”

“PCA” “Mechanism” “Head Assy”

“ACI”

“IO Firmware”

54 Commands

LOAD/UNLOAD 1Bh

The LOAD/UNLOAD command allows the host to specify that a tape cartridge present in the drive is either made ready for data transfer (“loaded”) or disabled for data transfer (if Prevent Media Removal is set). It can also cause the cartridge to be ejected from the drive (“unloaded”).

Pre-Execution Checks:

Illegal Field Reservation Deferred Error Unit Attention Diagnostic Status Media Information

If an unload is to be performed, the drive checks if the tape is currently being loaded. If it is, and additional sense of 0401h (becoming ready).

If a load is to be performed, the drive c hecks to ensur e that a ta pe cartri dge is present. If not, it reports and additional sense of 3A00h (medium not present). If the media is currently being unloaded or ejected, it reports

NOT READY and additional sense of 0400h (cause not reportable).

Command Descriptor Block:

CHECK CONDIT ION is reported with a sense key of NOT READY

CHECK CONDITION with a sense key of NO T READY

CHECK CONDITION with sense key of

Commands

7 6 5 4 3 2 1 0 0 1 2 3 4 5

Reserved (0 ) Hold EOT (0) ReTen Load

Operation Code (1Bh)

Reserved (0) Immed

Reserved (0) Reserved (0)

Control

CDB Fields:

Immed 0 The drive reports status afte r the command has completed.

1 The drive reports status when it starts the command (after any pre-execution checks

and prerequisite unloads have completed).

Commands 55

Hold 0 A normal load/unload will be perfor med.

1 A load will cause the cartridge to be pull ed in and se ated in the d rive, but the t ape will

not be threaded. An unload will cause the tape to be unthreaded, but the cartridge will not be ejected. In Hold position, the Cartridge Memory is accessible.

ReTen This field is ignored. Load 0 The drive perform s an unload operati o n.

1 The drive performs a load operation.

Load/Unload Specific Status:

Following a successful LOAD command, CHECK CO NDITION is posted to all initiators other than the initiator of the

UNIT ATTENTION, with additional sense of 2800h (not ready to ready

transition). There is an exception to this: if a load occurs when the tape is already loaded, no

UNIT A TTENTION is clear ed , unsoli cit ed positional sens e is set . The sen se

Once key will be

NO SENSE with additional sense of 0004h (BOT detected).

If an unformatted tape is inserted, the drive loads it and it behaves as if it is a blank tape.

If a cartridge with no Cartridge Memory or a failed Cartridge Memory is loaded,

CHECK CONDITION is returned with a sense key of MEDIUM ERROR,

with additional sense of 5200h (cartridge fault).

UNIT ATTENTION sense is generated.

LOAD command. The sense key is set to

56 Commands

Loading a Cartridge

The drive loads a tape automatically when it is inserted, without any host interaction. If the load is successful, media access commands are permissible (see the Media Access check).

If the tape is already loaded when a Load request is received, the tape is positioned at the beginning of the tape (as though a Unlike a “full” load,

UNIT ATTENTION with additional sense of 2800h (not

ready to ready transition) is not generated for other hosts. If the tape is in the process of being loaded when the Load request is receiv ed,

the drive will wait for the load to complete and, assuming the load was successful, take one of the following actions:

■ If the Load was issued by the current host (that is, a previous immediate-

reported load) and completed successfully, further action is taken.

REWIND had been sent).

GOOD status is reported. No

■ If the Load was issued by some other host (or was an autoload) and

completed su ccessfull y ,

UNIT ATTENTION and additional sense of 2800h (not ready to ready

CHECK CONDI TION is r eported, wit h a sense key of

transition).

■ If the Load was issued by the curr ent host and failed , CHECK C ONDIT ION is

reported, since a deferred error condition will exist for the current host.

■ If the Load was issued by some other host and failed, the load will be re-

attempted on behalf of the current host.

Unloading a Cartridge

If an unload is requested and there is a tape present in the drive (either loaded, loading or unloading):

1 Any buffered data is written to tape. 2 The tape is rewound to the physical BOM (beginning of media).

Commands

3 If medium removal is prevented,

sense key of

ILLEGAL REQUEST and additional sense of 5302h (medium

CHECK CONDITION is reported with a

removal prevented).

4 G

OOD status is reported if the tape unloaded successfully. Otherwise,

another unload operation is initiated on behalf of the host that issued the unload request.

Following an unload, any media access commands will be rejected by the Media Access check.

■ If an unload request is received while the tape is in the process of

unloading (for example, as a result of pressing the eject button), it will be queued until the unload is complete.

■ If an unload request is received while there is no tape present, or if a tape

is present but not loaded and medium removal is prevented,

GOOD status

is reported.

It is possible to unload and eject the cartridge by pressing the Eject button on the front panel.

Commands 57

LOCATE 2Bh

The LOCATE command moves the current logical position to the position specif i ed by the comm and . The n ew po siti on is sp ecif ie d by the off set fr om st art of the media in terms of b l ocks . The first bloc k (that is, BOT) is block address 0.

Any unwritten data is written to tape before the command is executed.

Pre-Execution Checks:

Illegal Field Reservation Deferred Error Unit Attention Media Access Diagnostic Status

Command Descriptor Block:

7 6 5 4 3 2 1 0 0 1 2 3

(MSB)

6 7 8 9

Reserved (0) BT (0) CP (0) Immed

Operation Code (2Bh)

Reserved (0)

Block Address

(LSB)

Reserved (0)

Partition (0)

Control

CDB Fields:

BT Block address Type. This field is not supported and sho uld always be set to zero indicating

that the Block Address field represents the count of all blocks and filemarks between the beginning of the media and the current logical position.

CP Change Partition. This field is not supported and should be set to zero. Immed 0 The drive only reports status after the Locate command has completed.

1 The drive reports status when it starts the comma nd and continue s with the positioning

in the background.

58 Commands

Block Address

The Block Address specifies the number of blocks and filemarks between BOM and the position to be located.

Partition Not supported.

Locate Specific Status:

Event Status Key Additional Sense

EOD encountered CHECK CONDN BLANK CHECK 0005h (EOD encountered). EOM encountered CHECK CONDN MEDIUM ERROR 00 02h (EOT encountered). EOM bit set. Failed to read data—media

error or non-fatal drive error

Early Warning EOM encountered

Data format corrupt CHECK CONDN MEDIUM ERROR 3001h (can’t read media, unknown format)

CHECK CONDN HARDWARE ERROR 3B00h (sequential positioning error)

Early warning end of medium informa t ion is not reported for Locate commands

Commands

Commands 59

LOG SELECT 4Ch

The Log Select command causes log data on the drive to be reset to its default value or to be set to an initiator specific value.

Pre-Execution Checks:

Illegal Field Reservation Deferred Error Unit Attention

Command Descriptor Block:

7 6 5 4 3 2 1 0 0 1 2 3 6 7 8 9

PC Reserved (0)

(MSB)

Operation Code (4Ch)

Reser v ed (0) PCR SP (0 )

Reserved (0)

Parameter List Length

(LSB)

Control

CDB Fields:

The following are valid combinations of values for the PCR (Parameter Code Reset), Parameter List Length and PC (Page Control) fields:

PCR P a r a m et er List Length PC Result

1 0 01b or 11b All the logs on the drive that can be rese t are reset

to their default values. 1 0 00b or 10b No action is taken and 0 >0 01b or 11b Data is sent from the host and is written to the

indicated logs, provided those logs are wr itabl e.

Otherwise

REQUEST

CHECK C ONDIT ION sta tus is r etu rned , the se nse k ey is set t o ILLEGAL

with additional sense of 2400h (Invalid Field in CDB).

GOOD status is returned.

PCR 0 Parameter Code Reset. The function performed is defined by the PC field.

60 Commands

SP 0 The Save Page (SP) flag is not supported and must be set to 0. PC The Page Control field defines the type of parameter values to be selected:

00b

No operation is performed. The Parameter List Length must be zero. If it is not, check

condition invalid field in CDB is set.

10b 01b The drive will clear logs as specified by the parameter data. 11b The drive will clear all of its internal logs.

Parameter List Lengt h

0 No data is to be transferred. This is not considered an error.

>0 Specifies how many bytes of parameter data are to be sent. The data transferred will

consist of zero or more 4-byte log page he aders with the page length in those hea ders set to zero. For each log page header received, the drive clears the associated log.

Commands

Commands 61

LO G SENSE 4Dh

LOG SENSE allows the host to read the drive’s logs. A single log is returned

with each invocation of

Pre-Execution Checks:

Illegal Field Deferred Error Unit Attention

The P age Code must matc h one of the supported log page codes. If it does not , then

CHECK CONDI T ION st atus is r eported . Sense data will be as descr ibed in

the Illegal Field Checks.

Command Descriptor Block:

7 6 5 4 3 2 1 0

LOG SENSE.

0 1 2 3 6 7 8 9

PC Page Code

(MSB)

Operation Code (4Dh)

Reserved (0) PPC (0) SP (0)

Reserved (0)

Allocation Length

Control

CDB Fields:

PC The Page Control field defines the type of log parameter to be returned:

00b Current Threshold Values—any parameters in the log that are counters contain the

maximum value that they can count to.

01b Current Cumulative Values—any parameters in the log that are counters contain their

current counts.

Note: Counts are reset to their de fault cumulative val ues (see belo w) following a p ower-on,

reset or bus device reset. Media related counts are also reset following a load.

10b Default Threshold Values—same as the Current Threshold Values

(LSB)

62 Commands

11b Default Cumulative Values—any parameters in the log that are counters contain the initial

values of those counters (set at power-on, reset, bus device reset and, in the case of media logs, load).

The PC field has no effect on the data returned when the selected log contains event or trace codes rather than counts.

Page Code The Page Code field identifies which log page is being requested by the host. See

the list of valid page codes.

Allocation Length

The Allocation Length field specifies the maximum number of bytes of data that should be returned to the host. The drive will return the entire log or Allocation Length bytes, whichever is the lesser.

Log Page Format

All log pages except Page 0 consist of a page code header followed by a number of parameters. The page header has the following format:

7 6 5 4 3 2 1 0

Commands

page 64 for

0 1 2

(MSB)

Page Code

Reserved (0)

Page Length

(LSB)

The page code is a byte value that uniquely identif i es w hich Log Page is being returned. The Page Length indicates the number of additional bytes in the parameters.

For the

Log Select com mand onl y, the four bytes sh o wn a bov e ar e sen t f or eac h

log page to be cleared. The Page Length field should be set to zero. For the

Log Sense command one or more parameters is sent. See the actual

page descriptions abo ve f or mor e inform ation. Not e that all the parameters f or a particular page must be sent. Each parameter has the following format:

7 6 5 4 3 2 1 0

(MSB)

1 2

DU (0) DS (1) TSD (0) ETC (0) TMC(0) LBIN LP

Parameter Code

(LSB)

Commands 63

7 6 5 4 3 2 1 0 3 4

(MSB)

Parameter Code A two-byte value that uniquely identifies the parameter within the log.

Parameter Length (n-3)

Parameter Bytes

(LSB)

DU, TSD, ET and TMC and LP

DS 1 Must be 1, indicating that drive will maintain the saving of data itself. Note that

LBIN 0 The parameter consists of ASCII characters.

LP List Parameter flag

Parameter Length The length of Parameter Bytes in bytes. Parameter Bytes Th e actu al par am ete r data.

0 Must be zero. For a full description of these fields refer to the SCSI-2 standard.

the host must set the SP bit to 1 in a

CONDITION

1 The parameter consists of binary data.

0 Indicates that the parameter is a counter. This is the case for all parameters except

MAM fields.

1 Indicates that the parameter is a list parameter, which is the case for all MAM

fields.

will result.

LOG SELECT command, otherwise a CHECK

Supported Log Pages Page

This SCSI log may be recovered using a Log Sense command with the PC field set to anything and the Page Code field set to 00h. The page lists the page codes of other logs supported by the drive. It can neither be reset nor written.

64 Commands

The page has the following format:

7 6 5 4 3 2 1 0 0 1

Reserved (0) Page Code (00h)

Reserved (0)

7 6 5 4 3 2 1 0 2 3 4 5 6 7 8 9

10 11 12

(MSB)

Sequential Access Device Log (0Ch)

Page Length (09h)

Supported Pages (00h) Write Error Counters (02h) Read Error Counters (03h)

TapeAlert Log (2Eh)

Tape Usage Log (30h)

Tape Capacity Lo g (3 1 h )

Data Compression Log (32h)

Performance Log (34h)

Write Error Counters Log Page

The Write Error Counters log is page 02h. The Page Length is 38h. There are seven paramete rs, 0 thr ough 6. Parameters 0 through 2 are not su pported and are returned as zero. All fields are four bytes long.

(LSB)

Commands

All these counters are updated when the data set is physically written. They relate to the current tape and are cleared when the tape is unloaded.

Parm. Definition Description

0 Errors corrected without substantial delay Total number of errors corrected without delay 1 Errors corrected with possible delays Total number of errors corre cted using retries 2 Total Sum of parameters 3 and 6 3 Total errors corrected The number of data sets that needed to be rewritten 4 Total times error correction processed Number of CCQ sets rewritten 5 Total data sets processed The total number of data sets written 6 Total uncorrected errors The number of data sets that could not be written

This data can be reset to zero, but not written.

Commands 65

Read Error Counters Log Page

The Read Error Counters log is page 03h. The Page Length is 38h. There are seven paramete rs, 0 thr ough 6. Parameters 0 through 2 are not su pported and are returned as zero. All fields are four bytes long.

All these counters are updated when the data set is ph ysi cally r ead. The y r elate to the current tape and are cleared when the tape is unloaded.

Parm. Definition Description

read retry

4 Total times error correction processed Number of times C2 correction is invoked 5 Total bytes processed The total number of data sets read 6 Total uncorrec ted errors The nu mber of data sets that co uld not be read after

retries

This data can be reset to zero, but not written.

Sequential Access D evice Log Page

66 Commands

The Sequential Access Device Log page is page 0Ch. The Page Length is 40h. Five parameters are supported, all eight bytes long:

Parm. Description

01h The number of data bytes received from application clients during write command

operations. This is the number of bytes transferred over SCSI, before compression.

02h The number of data bytes written to the media as a result of write command op er atio n s,

not counting the overhead from ECC and formatting. This is the number of data bytes transfer r ed to media, after compr ession.

03h The number of data bytes read from the media during read command operations, not

counting the overhead from ECC and formatting. This is the number of data bytes transferred from media with compression.

04h The number of data bytes transferred to the initiator or initiators during read command

operations. This is the number of bytes transferred over SCSI, after decompression.

0100h Cleaning required, a non-volatile cleaning indication.

A non-z er o v alue of the cleaning requir ed par ameter indicates that a condition requiring cleaning has been detected and a subsequent cleaning cycle has not yet been completed. The cleaning required parameter shall be persistent across hard resets and power cycles.

TapeAlert Log Page

The TapeA lert log page is page 2Eh. Th ere ar e 64 parameter s number ed fr o m 1 through 64. Only parameters 1 thr o ugh 18, 20 thr o ugh 23 and 29 through 39 have definitions for tape drives without attached loaders. The remaining parameters are always zero.

All parameters are one b yte long. E ach parameter is e ither zer o to indic ate the corresponding condition has not occurred or one to indicate that the corresponding condition has occurred. All log parameters are cleared when the log is read. The Log is also cleared at power on, on a reset condition and by a

Log Select command. Specif ic f lags may be cleared w hen corr ectiv e action

has removed the condition that caused the flag to be set. The supported parameters are as follows:

Parameter Description Type

1 Read Warning Warni ng 2 Write Warning Warning 3 Hard Error Warning 4 Media Critical 5 Read Failure Critical 6 Write Failure Critical 7 Media Life Warning 8 Not Data Grade Warning

9 Write-Protect Critical 10 No Removal Information 11 Cleaning Media Information 12 Unsupported Format I n formation 13 Recoverable Snapped Tape C ritical 14 Unrecoverable Snapped Tape Critical

Commands

Commands 67

Parameter Description Type

15 Memory in Cartridge Failure Warning 16 Forced Eject Criti c al 17 Read-Only Format Warning 18 Tape Directory Corrupted Warning 19 Nearing Media Life Warning 20 Clean Now Critic al 21 Clean Periodic War n i n g 22 Expired Cleaning Media Critical 23 Invalid Cleaning Cartridge Critical 29 Drive Maintenance Warning 30 Hardware A Cr it ical 31 Hardware B Critical 32 Interface Warning 33 Eject Media Critical 34 Download Fault Warning 35 Drive Humidity Warning 36 Drive T emperature Warning 37 Drive Voltage Warning 38 Predictive Failure Critical 39 Diagnostics Required Warning 50 Lost statistics Warning 51 Tape directory invalid at unload Warning 52 Tape system area write failure Critical 53 Tape system area read failure Critical 54 No start of data Critical 55 Loading failure Critical 56 Unrecove rable load failure Critical 57 Automation interface failure Critical 58 Firmware failure Warning

68 Commands

Tape Usage Log Page

The Tape Usage Log Page code is 30h. There are nine parameters. These are all read directly from the LTO-CM Tape Usage Log.

This data can be neither reset nor written.

Parm. Description Length

1 Thread Count 2 Total Data Sets Written 3 Total Write Retries 4 Total Unrecovered Write Errors 5 Total Suspen ded Writes 6 Total Fatal Suspended Writes 7 Total Data Sets Read 8 Total Read Retries 9 Total Unrecovered Read Errors

Tape Capacity Log Page

The Tape Capacity Log Page code is 31h. The Page Length is 20h. There are four parameters, 1 through 4. Parameters 2 and 4 are not supported and are returned as zero. All parameters are 4 bytes long. All parameters are in megabytes (1,048,576 bytes) and assume no compression. This data can be neither reset nor written.

Commands

4 8 4 2 2 2 8 4 2

The supported parameters are as follows:

Parm. Description Length

1 Main Partition Remaining Capacity 2 Alternate Partition Remaining Capacity 3 Main Partition Maximum Capacity 4 Alternate Partition Maximum Capacity

Commands 69

4 4 4 4

Data Compression Log Page

The Data Compression Log Page code is 32h and the page length is 4Ch. There ar e ten paramet ers, 0 thr ough 9. Para meters 0 and 1 are two byte s long. Parameters 2 through 9 are each 4 bytes long.

The supported fields are listed below. Parameters 2 through 9 occur as pairs that represent a large number of bytes transferred. The first four-byte parameter represents the number of whole megabytes transferred, rounded to the nearest megabyte. The second four-byte parameter represents the difference between this number of megabytes and the actual number of bytes. This may be a signed quantity.

This data may be reset, but may not be written.

Parameter Description Length

0 Read compression ratio X 100 1 Write compression ratio X 100 2 Megabytes transferred to host 3 Bytes transferred to host 4 Megabytes read fro m tape 5 Bytes read from tape 6 Megabytes transferred from host 7 Bytes transferred from host 8 Megabytes written to tape 9 Bytes written to tape

2 2 4 4 4 4 4 4 4 4

Performance Data Log Page

The Performance Data Log Page is 34h. This log is intended to report data of interest to a user/application on how efficiently the drive is being used.

Parameter Description Length Updated

0 Repositions per 100 MB 2 After each 100 MB has been physically written 1 Data rate into buffer 2 After each data set has been logically written

70 Commands

Parameter Description Length Updated

2 Maximum data rate 2 After each data set has been logically written 3 Current data rate 2 After each data set has been logically written 4 Native data rate 2 Fixed

All the parameters relate to the current tape. They are all cleared when the tape is unloaded, except Parameter 4, which is never cleared. All data will be reset when the log page is reset. The parameters are as follows.

Repositions per 100 MB Number of tape direction chang es pe r 100 MB written. Data rate into buffer Rate at which data is entering the buffer (after data compression), given in units of

100 KB/s. This is the true ‘tape’ data rate.

Maximum data rate Given the compressibility of the data that has been sent to the drive, this is the

maximum data rate that coul d be achi eved , given in units of 100 KB/s. The figure will be worked out based on the compressibility of each dataset received, datasets which have a compressibility higher than the compres sion ban dw idth of the drive will be ‘capped’.

Current data rate Rate at which data is being accepted by the drive before comp ression, given in units of

100 KB/s.

Native data rate The native rate (that is, without using compression) at which the drive writes data to

tape, given in units of 100 KB/s:

Drive Value Native Data Rat e

full-height 12Ch 30 MB /s

Commands

Commands 71

MODE SELECT 15h/55h

MODE SELECT is used to send configuration data to the drive. Both 6-byte and 10-byte versions of the command are supported.

The Mode Select parameter list is transferred from the host to the drive during the data-out phase. It contains zero or more bytes of information. If any information is sent, it should consist of a Mode Parameter Header followed by zero or more mode select pages. Internal parameters are set according to the values specified in the header and pages. Fields in the parameter list are checked and the operation will terminate if an error is found.

Note The drive does not check that the parameter list is correct before

modifying internal parameters. The list is checked as the operation proceeds, so if there is an error in the list, all parameters up to that point will be set to their new values, but the parameter in error and later parameter s w ill not be updated.

Pre-Execution Checks:

Illegal Field Reservation Deferred Error Unit Attention

Note Fail ure to flush write-behind data will be repo r t e d as a Deferred

Error.

72 Commands

The parameter list length must be such that only “entire” parts of a parameter list are sent. It is illegal to send a partial mode parameter header, a partial mode block descriptor or a partial mode page. If this happens, then

CONDITION

additional sense is set to 1A00h (parameter list length error). Extra checks may be performed on the data, see the descriptions for the

parameter list for more details.

status is reported. The sense key is set to ILLEGAL REQUEST. The

CHECK

Command Descriptor Block

6-Byte version

7 6 5 4 3 2 1 0

Operation Code (15h)

7 6 5 4 3 2 1 0 1 2 3 4 5

Reserved (0) PF Reserved (0) SP (0)

Reserved (0) Reserved (0)

Parameter List Length

Control

Commands

10-Byte version

7 6 5 4 3 2 1 0 0 1 2

(MSB)

6 7

(MSB)

8 9

CDB Fields:

PF Page Format

0The MODE SELECT parameter data is not SCSI-2 mode page compatible. Only the

parameter header and block descriptor may be sent.

1 The parameter data is SCSI-2 mode-page compatible.

SP Save Pages

0 This bit is not supported and must be zero.

Parameter List Length

0 No data is transferred.

>0 The length in bytes of the

Specific Status:

Operation Code (55h)

Reserved (0) PF Reserved (0) SP (0)

Reser v ed (0)

(LSB)

Parameter List Length

(LSB)

Control

MODE SELECT parameter list to be transferred.

Following a successful Mode Select command, Unit Attention status is posted to all initiators other than the initiator of the Mode Select command. The sense

Commands 73

key is set to UNIT ATTENTION. Additional sense is set to 2A01h (mode parameters changed).

Mode Parameter Pages

Mode data is recovered from the drive by means of a Mode Sense command. After modification, it is returned to the drive via a real-life, many hosts do not use data suits them into the drive.

Mode Page Representation

Certain conventions ar e us ed in the follow ing Mode Parameter pages in order to describe the nature of the parameters. Most paramet ers ar e giv en by name , followed by a number in brackets. The brackets have the following meanings:

Square brackets [ ] Square brackets indicate that the parameter may be modified. The number inside the

brackets is the default value for the field—in other words, the power-up or reset value.

■ MODE SELECT may modify this value by sending the page with a new value

in the field.

■ MODE SENSE (current values) will return the current value of the parameter.

■ MODE SENSE (default values) will return the value in brackets [].

■ MODE SENSE (changeable values) will return a value of all ones.

Round br ackets ( ) Round brackets indicate that the parameter is fixed. The n u mber inside the bra c ke t s i s

the fixed value for the field.

■ MODE SELECT must set the parameter to this value, otherwise CHECK

CONDITION

■

MODE SENSE (default values) will return the fixed value.

■ MODE SENSE (changeable values) will return a value of all zeros.

will be reported with a sense key of ILLEGAL REQUEST.

Mode Select command. In

Mode Sense and return whatever Mode Select

Mode Data Format

(MSB)

74 Commands

Mode data consists of a 4-byt e header , optionally f ollowed b y block descript or and Mode Parameter pages:

7 6 5 4 3 2 1 0

Mode Pa rameter Header

(LSB)

11 12

7 6 5 4 3 2 1 0

(MSB)

Mode Block Descriptor

(LSB)

(MSB)

Mode Parameter Pages

(LSB)

Mod e Pa rameter Pages

HP Ultrium drives support the following pages:

■ “Read-Write Error Recovery Mode Page” on page 78

■ “Disconnect-Reconnect Page” on page 79

■ “Control Mode Page” on page 81

■ “Data Compression Log Page” on page 70

■ “Device Configuration Page” on page 83

■ “Medium Partitions Mode Page” on page 85

■ “Fibre Channel Logical Unit Control Mode Page” on page 86

■ “Fibre Channel Port Control Mode Page” on page 87

■ “Information Exceptions Mode Page” on page 89

■ Return all pages (page 3Fh) — for MODE SENSE only

Mode Parameter Header

The Mode Parameter header must always be sent at the start of Mode Select data. It is always returned at the start of Mode Sense data.

Commands

6-byte Header

The 6-byte Mode Parameter header has the following format:

7 6 5 4 3 2 1 0 0 1 2 3

WP B u ffered Mode [001b] Speed (0)

Mode Data Len gth

Medium Type [00h]

Block Descriptor Length

Commands 75

10-byte Header

The 10-byte Mode Parameter header has the following format:

7 6 5 4 3 2 1 0

(MSB)

1 2 3

WP B u ffered Mode [001b] Speed (0)

Mode Data Length

Medium Type [00h]

4 5 6

(MSB)

Reser v ed (0)

Block Descriptor Length

Header Fields

Mode Data Length MODE SELECT: Mode Data Length field must be zero.

MODE SENSE: Mode Data Length field is set to the number of bytes of data available to

return excluding itself (in other words, the number of actual bytes available is mode data length + 1 for 6-b y te

SENSE

Note: The actual amount returned may be truncated to the allocation length

for the command.

Medium Type 00h The usual medium type when the drive is in normal tape drive mode.

MODE SENSE or +2 for 10-byte MODE

(LSB)

WP Write Pr otect. Ignored fo r MODE SELECT.

0MODE SENSE: The tape is write-enabled 1M

ODE SENSE: The tape is write-protected

Buffered Mode 0 The drive will not report

GOOD status o n WRITE and WRITE FILEMARKS commands until

all data (blocks and filemarks) has been successfully written to tape.

1 The drive w ill rep ort GOOD status for WRITE and WRITE FILEMARKS commands as soon

as all the data or marks specified in the command have been transferred to the data buffer. Data for multiple commands from different initiators may be buffered. This is the default value.

Note: It is strongly re c om mended that thi s fi eld is set t o 1, otherwise there will be

significant performance penalties. A method of flushing the buffer to tape without changing logical position is available with the

76 Commands

WRITE FILEMARKS command.

2 The drive w ill rep ort GOOD status for WRITE and WRITE FILEMARKS commands as soon

as all the data or marks specified in the command have been transferred to the data

buffer and all buffered data from different initiators has been successfully written to

the tape. This is th e maximum value.

Speed 0 The Speed field is not used and should be zero. Block Descriptor

Length

Only the values 0 and 8 are valid. Any value other than 0 or 8, reported. See the Parameter List check for details of the sense data generated.

0 No block descriptor is being transferred. 8 The Mode Parameter header must be followed by the 8-byte block descriptor

described in the next section.

Mode Block Descriptor

The format of the Mode Parameter block descriptor is as follows:

7 6 5 4 3 2 1 0

Commands

CHECK CONDITION status is

0 1

(MSB)

3 4 5

(MSB)

Density Code

Number of Blocks (0)

(LSB)

Reserved (0)

Block Length [0 or 800h]

(LSB)

Mode Parameter Block Descriptor Fields:

Density Code This specifies the format of the media loaded in the drive. See “REPORT DENSITY SUPPORT

44h” on page 123

Block Length This indicates the size of fixed blocks fo r fixed mo de

the decision process on whethe r to report an illegal length record on reads.

00h The default value when the drive is in normal tape drive mode.

for details.

READ and WRITE commands. It is also used in

Commands 77

Read-Write Error Recovery Mode Page

The Read-Write Error Recovery Mode Page has the following format:

7 6 5 4 3 2 1 0 0 1 2 3

4–7

9–11

TB Transfer Block

EER Enable Early Recovery

PER Post Error. Although this bit is changeable, the drive’s internal behaviour alway s

DTE Disable Transfer on Error

DCR Disable Correction

PS (0) Rsvd (0) Pag e C od e {0 1h}

Additional Page Length {0Ah}

Reserved (0) TB (0) Res (0) EER (1) PER [0] DTE (0) DCR (0)

Read Retry Count

Reser v ed (0)

Write Retry Count

Reser v ed (0)

Read-Write Error Recovery Page Fields:

0 Always set to 0, meaning that an unrecoverable data block will not be transferred to

the host.

1 The drive should attempt e rror correction before performing retries.

corresponds to PER=0.

0 The drive does not report

also be zero .

1 The drive reports CHECK CONDITION for recovered errors.

0 Always set to 0, meaning that the drive will not terminate the transfer for errors

recovered within the limits established by the read-write error parameters.

0 Always set to 0, meaning that the use of error correction codes for error recovery is

allowed.

CHECK CONDITION for recovered errors. The DTE bit must

78 Commands

Read Retry Count The number of times the drive will attempt its recovery algorithm during a read operation

before reporting an unreco verable error.

0 The drive will not use its recovery algorithm during read operations.

15h The drive will attempt 21 retries.

Write Retry Count The number of times the drive will attempt its recovery algorithm during a write operation

before reporting an unreco verable error.

0 The drive will not use its recovery algorithm during read operations.

0Ah The value for all Ultrium drives, giving 10 retries.

Disconnect-Reconnect Page

SCSI Drives

The Disconnect-Reconnect Page has the following format for SCSI drives:

7 6 5 4 3 2 1 0

Commands

0 1 2 3 4 5 6 7 8

9 10 11 12

13–15

PS (0) Rsvd (0) Page Code {02h}

Additional Page Length {0Eh}

Buffer Full Ratio (0)

Buffer Empty Ratio (0)

(MSB)

Bus Inactivity Limit (0)

(LSB)

(MSB)

Disconnect Time L i mit [0]

(LSB)

(MSB)

Connect Time Limit (0)

(LSB)

(MSB)

Maximum Burst Size [0]

(LSB)

Reserved (0) DTDC (0)

Reser v ed (0)

Commands 79

FC Drives

The Disconnect-Reconnect Page has the following format for FC drives:

7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9

10 11 12

13–15

PS (0) Rsvd (0) Page Code {02h}

Additional Page Length {0Eh}

Buffer Full Ratio (0)

Buffer Empty Ratio (0)

(MSB)

Bus Inactivity Limit (0)

(MSB)

Disconnect Time L i mit [0]

(MSB)

Connect Time Limit (0)

(MSB)

Maximum Burst Size [0]

EMDP (0) FAA [1] FAB (1) FAC (1) Reserved (0)

Reser v ed (0)

Disconnect-Reconnect Page Fields:

Buffer Full Ratio 0 Buffer management is controlled by the drive, so this should always be zero. Connect Time Limit 0 Buffer management is controlled by the drive, so this should always be zero.

(LSB)

Bus Inactivity Limit 0 This parameter is not supported and should be zero. Disconnect Time Limit 0 This parameter is not supported and should be zero. Connect Time Limit 0 This parameter is not supported and should be zero. Maximum Burst Size >0 The maximum amount of data that will be transferred during a data-in or data-out

phase before disconnecting. This field is in units of 512 bytes. The maximum burst size that the drive supports is 127 (7Fh) blocks of 512 bytes, that is, 64 KB less 512 bytes..

0 The drive may send bursts of any size. This is the default value.

EMDP (FC only) 0 Enable Modify Data Pointers is not facilitated by the dr iv e. T h e dr ive will always have

continually increasing and contiguous data relative offset values for FCP_DATA.

80 Commands

FAA (FC only) This bit, together with FAB and FAC, indicate whether the drive will use fairness arbitration

to send frames to the initiator.

0 The drive will not use fairness when arbitrating to send FCP_DATA frames. 1 T h e drive will use fairness when arbitrating to send FCP_DATA frames .

FAB (FC only) 1 The drive will use fairness when arbitrating to send FCP_XFER_RDY frames. FAC (FC only) 1 The drive will use fairness when ar bitrating to send an FCP_RSP frame. DTDC (SCSI only) 0 The Data Transfer Disconnect Control field is not supported and should be zero.

Note If the host does not grant disconnect privilege in its IDENTIFY

message these parameters become meaningless. The drive will stay connected on the bus for the duration of an operation or until the host sends a mid-operation

IDENTIFY granting

disconnect privi lege.

Control Mode Page

The Control Mode page is defined as follows:

7 6 5 4 3 2 1 0

PS (0) Rsvd (0) Page Code {0Ah}

1 2 3 4

Rsvd (0) RAC [0] Reserved (0) SWP (0) RAERP(0) UAAERP(0) EAERP(0)

5 6

(MSB)

7 8

(MSB)

TST (0) Reserved (0) GLTSD(0) RECL (0)

Queue Algorithm Modifier (0) Rsvd (0) QErr (0) DQue (0)

Reserved (0) Autoload Mode

Extended Self-Test Completion Timeout (0)

Page Length {0Ah}

Ready AER Hold-off Period (0)

(LSB)

Busy Timeout Period (0)

(LSB)

Commands

Commands 81

Control Mode Page Fields:

Autoload Mode 0 If a cartridge is inserted, the drive pulls it in and t hreads the tape.

1 or 2When a cartridge i s inserted, the drive pulls it in but does not thread the tape. In this

position, only the Cartridge Memory is accessible.

All other values are i nvalid.

Data Compression Characteristics Page

The Data Compression Characteristics Mode page is defined as follows:

7 6 5 4 3 2 1 0 0 1 2

DCE [1] DCC (1) Reserved (0)

DDE (1) RED (0) Reserved (0)

(MSB)

7 8

(MSB)

11 12 15

Page Code {0Fh}

Page Length {0Eh}

Compression Algorithm (1)

(LSB)

Decompression Algorithm (1)

(LSB)

Reserved (0)

Data Compression Characteristics Mode Page Fields:

DCE Data Compression Enable. This bit controls whether the drive uses compression when

writing. The value has no measning when reading, that is, if the tape contains compressed data, decompression will occur regardless of the setting of this bit. The bit is analogous to the Select Data Compression Algorithm field on the Device Configuration mode page (see

01Compression is disabled

Compression is enabled

DCC Data Compression Capa ble

Read only. It will have the value of 1, indicating that compression is supported.

page 84).

82 Commands

DDE Data Decompressio n Enable

Read only. It will have the value of 1, indicating that compression is enabled.

RED Repo rt Exception on Decompression

Read only. It will have the value 0, meaning that the drive returns status when it encounters data that cannot be decompressed. This applies when data has been compressed with an unknown or unsupported compression algorithm.

Compression Algorithm

Decompression Algorithm

This indicates which compression algorithm will be used to process data from the host when the DCE bit is set to one. If the host selects an algorithm which the drive does not support, the default algorithm (ID 1) is supported.

This will also always be 1, indicating that the defau lt decompr ession alg orithm sho uld be used.

CHECK CONDITION is returned, with a sense key of ILLEGAL REQUEST. Only

Device Configuration Page

The drive supports the Device Configuration Page, which has the following format:

7 6 5 4 3 2 1 0

PS (0) Rsvd (0) Page Code {10h}

1 2

Rsvd(0) CAP (0) CAF (0) Active Format (0)

3 4 5 6

(MSB)

7 8

DBR (0) BIS (1) RSmk(0) AVC (0) SOCF (00) RBO(0) REW (0)

9 10 11 12 13

EOD Defined (000) EEG (1) SEW (1) R e served (0)

(MSB)

Additional Page Length {0Eh}

Write Buffer Full Ratio (0)

Read Buffer Empty Ratio (0)

Write Delay Time: [012Ch]

Buffer Size at Early Warning (0)

CHECK CONDITION

Commands

Active Partition (0)

(LSB)

Gap Size (0)

(LSB)

Commands 83

14 15

7 6 5 4 3 2 1 0

Select Data Compression Algorithm [ 1]

Reserved (0)

Pre-Execution Checks:

The only check made when this page is sent in Mode Select data is Parameter List.

Changeable Parameters:

Write Delay Time

Select Data Compression Algorithm

This field can be modified by a MODE SELECT command, and this change will be refl ec ted in a subsequent as zero, and so the data in the buffer will never be flushed. The default value is zero. The field is fully supported. The default value is 12Ch, representing a 30 second time delay.

0 The drive will never flush buffered data to tape as a result of a time-out.

>0 The time in 100 ms increments that the drive should wait with unwritten data in the buffer

0 Use Scheme 2 of the LTO-DC algorithm (pass-through mode). Note that clearing this

1 Use the default compression scheme. This is the default.

MODE SENSE command. However the actual value used as the delay time will remain

and no activity on the interface before forcing data to tape. The delay is timed from the completion of the preceding

parameter is not advised.

WRITE or WRITE FILEMARKS command.

Unchangeable Parameters:

PS 0 CAP 0 The Change Active Partition flag should be 0 since multiple partitions are not supported. CAF 0 The Change Active Format flag should be zero since changing formats is not supported. Active Forma t 0 Changing formats is not supported. Active Partition 0 Multiple partitions are not supported. Write Buffer

Full Ratio Read Buffer

Empty Ratio

0 Buffer management is done by the drive.

DBR 0 The Data Buffer Recovery flag should be clear since this feature is not supported. BIS 1 The Block Identifiers Supported flag should be set since block identifiers are supported.

84 Commands

Rsmk 0 The Report Set Marks flag should be clear since this feature is not supported. AVC 0 The Automatic Velocity Control flag should be clear since velocity control is managed by the

drive.

SOCF 0 The Stop On Consecutive Filemarks flag should be clear since this feature is not supported. RBO 0 The Recover Buffer Order flag should be clear since this feature is not supported. REW 0 The Report Early Warning on read flag should be clear since this feature is not supported. Gap Size 0 There is no concept of inter-block gaps in the format. EOC Defined 0 EEG 0 The Enable EOD Generation flag should be set since EOD generation is always enabled. SEW 1 The Synchronize at Ea rly Warning flag should be set since this feature is supported.

Commands

Buffer Size at Early Warning

0 The Buffer Size at Early Warning field should be zero as this cannot be set.

Medium Partitions Mode Page

The Medium Partitions Mode Page has the following format. Note that none of the fields are changeable. The Partition Size will be patronized.

7 6 5 4 3 2 1 0 0 1 1 1 2 1 3

4–7

8 9

Maximum Additional Partitions (0)

FDP (0) SDP (0) IDP (0) PSUM (11b) POFM (0) CLEAR (0) ADDP (0)

Reserved (0) P a rtition Units (9)

Page Code (11h)

Page Length (08h)

Additional Partitions Defined (0)

Medium Format Recognition (3)

Reserved (0)

Partit ion Size

Commands 85

None of the fields in this mode page are changeable.

Maximum Additional Partitions

Additional Part i ti o ns Defined

FDP 0 The Fixed Data Partitions bit is not supported and must be set to zero. SDP 0 The Select Data Partitions bit is not supported and must be set to zero. IDP 0 The Initiator Defined Partitions bit is not supported and must be set to zero. POFM 0 The Partitions on Format bit is set to zero since the drive does not support

CLEAR 0 Set to zero indicating SCSI-2 compatibility. ADDP 0 Set to zero indicating SCSI-2 compatibility. Medium Format

recognition PSUM 3 Partition Size Unit of Measure: The value of 11b indicates that the units of

Partition Units 9 This defines the units of the Partition Size fie ld as 109 bytes, in other words

Partition Size 100 Gen 1 tape loaded

0 Zero is returned, indicating that no additional partitions are present or

supported.

0 Zero must be returned, indicating that no additional partitions are present

or supported.

the

FORMAT MEDIUM command through which the tape could be

partitioned.

3 This indicates that the drive is capable of format and partition recognition.

measure for the Partition Size descriptor are defined by the Partitions Units field: 10

in gigabytes.

200 Default value. No data cartridge present or Gen 2 tape loaded.

(Partition Units)

bytes.

Fibre Channel Logica l Unit Contr ol Mode P age

This page is supported for Fibre Channel only:

7 6 5 4 3 2 1 0

PS (0) Rsvd (0) Page Code {18h}

1 2 3

4–7

86 Commands

Page Length {06h)

Reserved (0)

Reserved (0) EPDC[1]

Reserved (0)

EPDC 0 The target doe s not use t he prec ise deli ver y func tio n and ignor es the con tent s of th e CRN f ield

in the Fibre Channe l Ext end ed Link Ser vi ce FCP_CNTL. HP Ultrium drives support this feature by default.

1 The logical unit uses the precise delivery function defined in the FC P- 2 standard. It makes use

of the CRN field.

Fibre Channel Port Control Mode Page

This page is supported for Fibre Channel only:

7 6 5 4 3 2 1 0

PS (0) Rsvd (0) Page Code {19h}

1 2 3

Rsvd (0) PLPB[0] DDIS[0] DLM[1] RHA[0] ALWLI[0] DTIPE[0] DTOLI[0]

4–5

6 7

Reserved (0) RR TOV Unit (3)

Resource Recovery Tim e-Out Value

The Fibre Channel Port Control Page allows you to set the initialization and addressing behavior of the Fibre Channel interface.

Page Length {06h)

Reserved (0)

Commands

PLPB Prevent Loop Port Bypass

0 The target allows the Loop Port By pass (LPB) and Loop Po rt Enable (PBE) primitiv e sequen ces

to control the port bypass circuit.

1 The target ignores any Loop Port Bypass (LPB) and Loop Port Enable (LPE) primitive

sequences. The loop port remains enabled.

DDIS Disable Discovery

0 The target must wait to recei ve an Add ress Dis covery Link Serv ice (ADIS C) or Po rt Discov ery

Link Service (PDISC) before it resumes processing tasks for the initiator.

1 The target does not require receipt of address or Port Discovery following loop initialization.

It resumes processing of tasks on completion of lo op in i ti ali zation.

Commands 87

DLM D isable Loop Master. The drive will never attempt to be a loop master.

0 The target may become loop master during the loop initialization process. 1 The target does not become loop master. It only repeats LISM frames it receives. This allows

the initiator to be loop master during loop initialization.

RHA Require Hard Address

0 The target follows the normal initialization procedure, including the possibility of obtaining

a soft address during the loop initialization process.

1 The target only attempts to obtain its hard address available in the SCA connector or device

address jumpers during loop initialization. The target does not attempt to obtain an address during the LISA phase of initialization.

ALWLI Allow Login Without Loop Initialization

0 The target is required to verify its address through the loop initialization process before a

1 The target uses the hard address availabl e in the SC A connec tor or de vice add ress jump ers

and accept logins without verifying the address with loop initialization.

DTIPE Disable Target Initiat ed P or t Enable

0 The target enables its port into the loop without waiting for a Loop Port Enable primitive. 1 The target waits for an initiator to send the Loop Port Enable primitive before inserting itself

into the loop. The target uses the hard address available in the SCA connector or device address jumpers to determine if primitives ar e addresse d to it. A Loop Port Enable primitive with the broadcast address also causes the target to insert itself into the loop.

DTOLI D isab le Target Originated Loop Initialization

0 The target generates the Initializing LIP after it enables a port into a loop. 1 The target does not generate the Initializing LIP following insertion into the loop. The target

will respond to an Initializing LIP when it is received. The target generates the Loop Failure LIP if it detects loop failure at its input and the Initializing LIP when the loop failure is corrected.

RR TOV Unit Resource Recovery Time-Out Value Unit. The field specifies the unit of measure as follows:

0 No timer specified 11 ms 3100 ms

Resource Recovery Time-Out Value

88 Commands

5 10000 ms

The value cannot be changed through

MODE SELECT, but may change as a result of Fabric Log in,

FLOGI, which changes the E_D_TOV on which this timer is based.

Information Exceptions Mode Page

The Information Exceptions Mode page is used to control exception reporting through the “TapeAlert Log Page” on page 67:

7 6 5 4 3 2 1 0

PS (0) Rsvd (0) Pa ge Code {1Ch}

1 2

Pe r f (0) Reserved (0) DExcpt Test Rsvd (0) LogErr (0)

3 4

(MSB)

7 8

(MSB)

Perf 0 Informational exception operations that cause delays are acceptable. DExcpt Disable Exception Control. It must be zero when the Test Flag Number is zero. When the Test

Flag Number contains a valid non-zero value, the DExcpt flag can be 0 or 1.

0 Information exception operations are enabled. The reporting of information exception

conditions is determined from the MRIE field.

1 A DExcpt bit of one indicates the target will disable all information exception operations.

The method of reporting informational exceptions field is ignored when DExcpt is set to one.

Test 0 If the Test flag is clear the next command will be processed normally.

1 A test bit of one will generate false informational exception conditions. As a result, the

next SCSI command after the Mode Select will return key of exceeded - false).

The Test bit will never be read as 1 when performing a Mode Sense command. This is not an indication that the drive is in test mode. For example, using the Test bit an d Test Fl ag Numbe r, it may be po ssible to set a flag with the DExcpt bit set to 1. When the DExcpt bit is next set, the drive will report with a sense ke y of threshold exceeded - false). In order to set the DExcpt bit again, note that the Test bit must still be set during the Mode Select command.

Reserved (0) MRIE (3h)

RECOVERED ERROR and additional sense of 5DFFh (failure prediction threshold

RECOVERED ERROR and additional sense of 5DFFh (failure prediction

Page Length {0Ah)

Interval Timer (0)

(LSB)

Report Count/Test Flag Number

(LSB)

CHECK CONDITION with a sense

CHECK CONDITION

Commands

Commands 89

LogErr 0 Log Errors bit. This bit must be zero, indicating that the logging of informational

exception conditions within the drive is vendor-specific.

MRIE Method of Reporting Informational Exceptions

3h This field indicates the method used by the target to report informational exception

conditions and must be set to 3. The target will report informational exception conditions by returnin g a

RECOVERED ERROR with additional sense of 5D00h (failure prediction threshold

exceeded). Th e command that has the

CHECK CONDITION status on any command. The sense key will be set to

CHECK CONDITION will complete without error

before any informational exception condition may be reported.

Interval Timer 0 Must be zero, indicating that the drive only reports an informational exception condition

once.

Report Count/Test Flag Number

0 If the Test bit is zero, this field is the Report Count and must be zero, indicating that there

is no limit on the number of times the drive can report an informational exception condition.

n If the Test bit is one, this field is the Test Flag Number , tha t is, the n um be r of a suppo r t ed

TapeAlert flag. The target will generate a test informational exception condition. As a result, the next SCSI command after Mode Select will return sense key of

RECOVERED ERROR and additional sense of 5DFFh (failure prediction

CHECK CONDITION with a

threshold exc eeded - false). The following are valid se tti ng s:

1 through 64 This sets the TapeAlert flag with this number in the Log page.

90 Commands

-1 through -64

(FFFFFFFFh–FFFFFFC0h)

This clears the TapeAlert flag indicated by the absolute value of the Test Flag Number.

32767 (7FFFFh) This sets all the TapeAlert flags supported by the target in the

Log page.

Note that if an attempt is made to set or clear a flag that is not supported by the drive,

REQUEST

CHECK CONDITION will be reported with a sense key of ILLEGAL

and additional sense of 2600h (invalid field in parameter list).

MODE SENSE 1Ah/5Ah

MODE SENSE allows the drive to return its current configuration and report which configuration parameters can be changed through

The mode sense header, block descriptor (optional), and zero or more of the are sent to the host. Mode pages contain drive configuration parameters. Some of these parameters are fixed, others are configurable (through the

MODE SELECT command). The host should use MODE SENSE to determine

which drive parameters are configurable and what their current values are before using mode select to alter them.

MODE SELECT.

Commands

Note See

MODE SELECT on page 72 for full descriptions of the Mode

Parameters.If a

MODE SENSE command is issued whilst an

immediate reported Load command is executing or close to completing then the values of some parameters in some mode pages which depend on the results of the load may be undefined.

Similarly, the write-protect field in the Mode Parameter Header will be unstable unless a cartridge is present and medium removal is prevented.

Pre-Execution Checks:

Illegal Field Reservation Deferred Error Unit Attention

The page code field must contain a valid mode page code or the value 0 or the valu e 3Fh. If it does not then

CHECK CONDITION status is reported. Sense

data will be as described in the Illegal Field Checks.

Command Descriptor Block:

6-Byte Version

7 6 5 4 3 2 1 0 0 1 2

Reserved (0) DBD Reserved (0)

PC Page Code

Operation Code (1Ah)

Commands 91

7 6 5 4 3 2 1 0 3 4 5

Reserved (0)

Allocation Length

Control

10-Byte Version

7 6 5 4 3 2 1 0 0 1 2 3

(MSB)

6 7

(MSB)

8 9

Reserved (0) DBD Reserved (0)

PC Page Code

Operation Code (5Ah)

Reser v ed (0)

(LSB)

Allocation Length

(LSB)

Control

CDB Fields:

DBD Disable Block Descriptors flag

0 Allows the drive to return the 1 Prevents the drive from returning the

PC Page Control—Indicates the type of page parameter values to be returned to the host, as shown in

the following table:

7 6 Description

00Report Current Values: the current values of the parameters are returned.

MODE SELECT bl ock descriptor.

MODE SELECT block descr iptor.

01Report Changeable Valu es: the pag e retur n ed has its non- chan ge able parameter

fields cleared to 0. The fields tha t ar e changeable are set t o all 1’s.

10/1Report Default Values: the page returned contains the power-on/reset/bus-device-

reset values of the mode parameters.

Page Code This allows the host to select any specific pag e, or all the pages su ppo r ted by the driv e.

0 The drive returns no mode pages, so on ly the hea de r and block descriptor are

returned.

92 Commands

Allocation Length

Any mode

The drive returns that page.

page code

3Fh The drive returns all mode pages.

Specifies the number of bytes that the host has allocated for returned MODE SENSE data.

0 No data transfer will occur. This is not considered an error.

n The maximum number of bytes which the drive should return in its data-out phase. Either

the entire mode page or allocation length bytes of the page are returned, whichever is least.

Commands

Commands 93

PREVENT/ALLOW MEDIUM REMOVAL 1Eh

PREVENT/ALLOW MEDIUM REMOVAL tells the drive to enable or disable the

rem o val of the cartridg e. When cartridge removal is pre ven ted, the fr ont panel eject button is completely

disabled (though a ‘forced eject’ will still work). An Unload command issued by a host will result in

REQUEST

or MEDIUM REMOVAL PREVENTED.

When cartridge removal is enabled, pressing the front panel eject button or sending an Unload command f rom a host will cause the media to be unloaded and ejected.

Removal prevention is on a per-host basis. All the hosts have to allow media removal for any of them to do so.

Note If a firmware upgrade is initiated over any interface, the

cartridge will be ejected from the drive regardless of the state of this command.

Pre-Execution Checks:

Illegal Field Reservation Deferred Error Unit Attention

CHECK CONDITION. The sense key will be ILLEGAL

94 Commands

1–3

4 5

Command Descriptor Block:

7 6 5 4 3 2 1 0

Operation Code (1Eh)

Reserved (0)

Reserved (0) Prevent

Control

CDB Fields:

Prevent 00b Medium removal is allowed for the drive

01b Media removal is prohibited for the drive

10b, 11b Invalid

READ 08h

READ transfers zero or more data blocks to the host starting at the current

logical position.

Pre-Execution Checks:

Illegal Field Fixed Bit Reservation Deferred Error Unit Attention Media Access Diagnostic Status

If both the SILI and Fixed bits are set, CHECK CONDITION status is reported. Sense data is as described in the Illegal Field Checks. The field pointers indicate the Fixed bit field.

Note Transfers of 4 bytes or less are not supported.

Command Descriptor Block:

7 6 5 4 3 2 1 0

Commands

0 1 2

(MSB)

4 5

Operation Code (08h)

Reserved(0) SILI Fixed

Transfer Length

(LSB)

Control

CDB Fields:

If the Fixed flag is clear and Transfer Length is not zero, then a single block of the length in Transfer Length is to be transferred. If the next block on tape is of this length or shorter it is transferred to the initiator. If the n ext block is longer than this length, only the length requested is returned and the logical position is set to after the record. If the length of the block was the same as the Transfer Length field, same as in Transf er Length and the Suppr e ss Illegal Length Indicator (SILI) flag was clear, below. If the length of the block w as n ot th e same a s in Transfer Length and the Suppress Illegal Length Indicator (SILI) flag was set,

GOOD status is returned. If the length of the block was not the

Check Condition status is returned, ILI will be reported as described

Good status is returned.

Commands 95

If the fixed f lag is set and the T r ansf er Length f ield is not zero and the Suppress Illegal Length Indicator (SILI) flag is clear, a sequence of blocks of the curr ently configured block length is to be returned, the number of blocks being indicated in the Transfer Length field. If there is a sequence of blocks of this length on the tape, they are returned to the initiator with

GOOD status. If a block that is

longer than the configured length is encountered before the sequence is complete, the blocks up to that block are returned followed by the configured length from th e record that was too long and

Check Condition status (ILI will be

reported as described below). If a block that is shorter than the configured length is encountered before the sequence is complete, the blocks up to that block are returned followed by all of that block and

Check Condition status (ILI

will be reported as described below). The current position is set after the last block that was returned or partially returned

SILI Suppress Incorrect Length Indicator

0 The read operation is terminated when the length of a block (on the tape) differs from the

Transfer Length. Transfer Len gth bytes of data will have been transferr ed . The logi cal tap e position will be the EOM side of the illegal sized blo c k.

1 The drive will not report CHECK CONDITION status if the only error is that the Transfer

Length is not equal to the actual block length recorded on the media.

Fixed 0 The Transfer Length field specifies the length of the transfer in bytes.

A single block of the length in Transfer Length is to be transferred.

If the next block on tape is of Transfer Length, it is transferred to the initiator

■

and

GOOD status is returned.

■ If the next block on tape is not of Transfer Length:

■ If it is shorter, the whole block is transferred to the initiator.

■ If it is longer, only the length requested is returned and the logical position is

set to after the record.

■ If SILI = 0, CHECK CONDITION status is returned. ILI is reported as described

below.

■ If SILI = 1, GOOD status is returned.

96 Commands

1 The Transfer Length field specifies the length of the transfer in blocks. The si ze of each

block (in bytes) is specified by the current block length specified in the Mode Parameter block descriptor. If SILI = 0, a sequence of blocks of the currently configured block length is to be returned, the number of blocks being indicated in the Transfer Length field.

If there is a sequence of blocks of this length on the tape, they are returned to

■

the initiator with

■ If a block that is shorter than the configured length is encountered before the

GOOD status.

sequence is complete, the blocks up to that block are returned followed by all of that block and

CHECK CONDITION status (ILI will be reported as described

below). The current position is set after the last block that was returned.

■ If a block that is longer than the configured length is encountered before the

sequence is complete, the blocks up to that block are returned followed by the configured length from the record that was too long and status (ILI will be reported as described below). The current position is set after the last block that was partially returned.

Transfer Length

0 No data is transferred. This is not considered an error and the current logical position will

be unchanged.

>0 The amount of data to be transferre d, in bytes or blocks as specified by the Fixed field.

Note: Transfers of 4 bytes or less are not supported.

Read Specific Status:

Event Status Key Notes

SILI error CHECK

COND’N

Filemark encountered during a read

EOD encountered during a read

EOP/M encountered during a read

CHECK COND’N

NO SENSE

BLANK CHECK

MEDIUM ERROR

ILI and Valid bits are set. The information bytes will be set as follows: Variable Block Mode: The difference between the requested T ransfer Length and the actual block size. If the block size is bigger than the Transfer Length, this will be negative (twos complement). Fixed Block Mode: The difference between th e requested number of records and the number of who le goo d records transferred. If the last record was under length, it is considered “whole good” for the purposes of this calculation.

The Mark bit is set. Logical position will be on the EOM side of the filemark. Additional sense is 0001h (filemark detected). The logical position will be on the EOM side of the fil emark. Residue information is as described below.

Additional sense is set to 0005h (EOD detected). Residue information is as described below.

The EOM bit is set. Additional sense is set to 0002h (EOP/M detecte d). Residue information is as described below.

Commands

CHECK CONDITION

Commands 97

Event Status Key Notes

Failure to read data through media error or non-fatal drive error

Corrupt data format

Blank media encountered during a read

CHECK COND’N

MEDIUM ERROR

BLANK CHECK

Additional sense is set to 1100h (unre c overed read error) or 3B00h (sequential positioning error). Residue information is as described below.

Additional sense set to 3002h (can’t read media).

Caused by an attempt to read an unformatted tap e. Add itional sense is set to 5000h (EOD not found). Residue information is as shown below.

Note Early warning end of medium information is not reported on

reads.

Residue Information:

The Valid bit will be set. The information bytes will be as follows:

Variable Block Mode The requested transfer length (in bytes).

Fixed Block Mode The difference (in blocks) between the requested transfer size and the actual number of

blocks transferred. A partially transf er re d blo ck is no t counted , so fo r ex amp le , if 3.5 out of 10 blocks have been transferred the residue will be 7.

If the last block is an ill egal le ngth block, it is not counted a mong those transferred. F or example, if 4 legal length blocks and 1 illegal length block have been transferred out of a total of 10, the residue will be 6.

98 Commands

READ ATTRIBUTE 8Ch

The READ ATTRIBUTE command allows an application client to read attribute values to MAM (Medium Auxiliary Memory) and also to discover what MAM exists at the device server.

Pre-Execution Checks:

Illegal Field Fixed Bit Flag Link Bad LUN Reservation Deferred Error Unit Attention Media Access Diagnostic Status

If the MAM is not accessible because there is no tape in the drive, CHECK

CONDITION

of 3A00h (medium not present).

is reported with a sense key of NOT READY and additional sense

Commands

If the MAM is not accessible even though a tape is in the drive,

CONDITION

is reported with a sense key of MEDIUM ERROR and additional

CHECK

sense of 0410h (Media Auxiliary Memory is not accessible). If the MAM has failed,

MEDIUM ERROR and additional sense of 1112h (Media Auxiliary Memory

CHECK CONDITION is reported with a sense key of

read error).

Command Descriptor Block:

7 6 5 4 3 2 1 0 0 1 2

(MSB)

3 4 5 6 7

Reserved (0) Servi ce Action

Operation Code (8Ch)

Element Address (0)

(LSB)

Element Type Code (0)

Volume N umber (0)

Reserved (0)

Partition Number (0)

Commands 99

7 6 5 4 3 2 1 0

10 13 14 15

(MSB)

First Attribute ID

(LSB)

Allocation Length

(LSB)

Reserved (0)

Control

CDB Fields:

Service Action Service actions are defined as follows. The data returned for each Service Action is described

below.

Code Name Description

00h Attribute Values Returns the attribute values. 01h Attribute List Returns a list of attribute identifiers available) non-existent. 02h Volume List Returns a list of volume numbers available. 03h Partition List Returns a list of partition numbers available.

04h–1Fh Reserved

Element Address Set to zero to indicate that Ultrium tapes only support a single element. Element Type Code Set to zero to indicate that Ultrium tapes only support a single element. Volume Number Set to zero to indicate that Ultrium tapes only support a single volume. Partition Number Set to zero to indicate that Ultrium tapes only support a single partition. First Attribute ID The identifier of the first attribute to be returned. This is not checked if the Service Action value

is 01h (Attribute List).

100 Commands

HP C737990900 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

The Purpose of this Manual

Related Documents

Documentation Map

General Documents and Standardization

contents

Interface Implementation

The SCSI Interface

Supported Messages

Supported Commands

SCSI Features

Design Approach

Power-On

Reset Strategy

Abort Handling

Bus Pari ty Errors (Parallel SCSI only)

Disconnect Strategy (Parallel SCSI only)

Multi-Ini t iator Support

Fibre Channel Operation

Fibre Channel Addressing

Names

Addresses

HP’s Implementation of Names and Addresses

Implications for Libraries

Field Replaceable Units

Descriptions of Signals (Parallel SCSI only)

Messages

Message Out Support (Parallel SCSI only)

Message In Support (Parallel SCSI only)

Extended Message Support

Status

Commands—Introduction

Summary

Command Details

Pre-Execution Checks

Bad LUN Check

Deferred Error Check

Diagnostic Status Check

Fixed Bit Check

Flag Link Check

Illegal Command Check

Illegal Field/Request Check

Media Access Check

Media Information Check

Media Write Check

Parameter List Check

Reser vation Check

Unit Attention Check

Command Descriptor Block

Commands

ERASE 19h

INQUIRY 12h

INQUIRY Data Pages

Vital Product Data Pages

Supported Vital Product Data Pages Page

Unit Serial Number Page

Device Identification Page

Defined Ide nti fiers

Driv e Component Revi sion Levels Pages

LOAD/UNLOAD 1Bh

LOCATE 2Bh

LOG SELECT 4Ch

LO G SENSE 4Dh

Log Page Format

Supported Log Pages Page

Write Error Counters Log Page

Read Error Counters Log Page

Sequential Access D evice Log Page

TapeAlert Log Page

Tape Usage Log Page

Tape Capacity Log Page

Data Compression Log Page

Performance Data Log Page

MODE SELECT 15h/55h

Mode Parameter Pages

Mode Page Representation

Mode Data Format