HP LTO 4 SAS, LTO 4 FC manual ACI command set, ACI commands that affect drive streaming performance

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SCSI pass-through mode

cartridge at the moment that the drive starts to pull it into the drive, if it is configured for that type of operation.

This degree of control over synchronization cannot be achieved though the host’s backup software; it must be controlled directly by the library controller. Most tape libraries work this way today. The process is transparent to the backup software.

SCSI pass-through mode

The ACI protocol allows the transfer of “packetized” SCSI commands from an attached controller and submit them to the tape drive as if they have been received on the drive’s own SCSI bus. This enables the attached controller to access and control the drive in exactly the same way as it would via the SCSI bus.

ACI command set

The following ACI commands are supported on HP Ultrium drives:

	Mandatory Commands
00h	Get Drive Info
01h	Load
02h	Unload
03h	Get Drive Status
04h	Set Drive Configuration
05h	Get Drive Configuration
06h	Reset
07h	Set Baud Rate
08h	No Op
09h	Get Error Info
0Ah	Acknowledge Attention

	Optional Commands
40h	Send SCSI Command
42h	Send Firmware Image
43h	Get Firmware Segment
49h	Get Buffer Size
4Ah	Send Firmware Segment
4Bh	Set Time
4Ch	Get Time

ACI commands that affect drive streaming performance

Commands that alter the state of the drive in some way will affect the performance of the drive when stream reading or writing. It is recommended that no command within the following set are sent to the drive while the drive is writing or reading as it would affect the data throughput to or from the drive:

•Load

•Unload

•Send Firmware Image

•Send Firmware Segment

•Reset

•Set Drive Configuration—if the host (SCSI or FC) is reconfigured

38 Supporting Ultrium features

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Contents HP LTO Ultrium tape drives technical reference manual volume 2 software integrationLTO 4 FC, SCSI and SAS drives HP restrictedLegal and notice information 2 Configuration and initialization Contents1 Designing backup applications 3 Use of tapes5 Supporting Ultrium features 4 Factors affecting performance6 Sense keys and codes 7 Exception handlingHP restricted Documents specific to HP Ultrium drives Related documentsDocumentation map Drives-generalCartridges Installation and configurationOperation InterfaceMaintenance and troubleshooting Dealing with errorsLTO Ultrium features General documents and standardizationOptimizing performance 1 Designing backup applicationsNon-immediate commands Large data transfer sizeInformation in Cartridge Memory Cleaning tape headsManaging the use of tapes Monitoring tape useTapeAlert Design goals for LTO backup applicationsDiagnostic logs Displaying drive informationInclude the capability to download firmware Operating system drivers 2 Configuration and initializationInquiry string recovery SCSI protocol, regardless of transport or interface type Example16 Configuration and initialization Supporting additional LUNs Support for additional LUNEnabling additional LUN support 18 Configuration and initialization 3 Use of tapes Using Cartridge Memory attributesUsing MODE SENSE LTO cartridge memoryInterpreting Log Sense data Tape status and capacityFinding the remaining capacity CDB fields Using the SET CAPACITY commandCommand descriptor block How WORM media works Changes to SCSI commandsWORM media New additional sense codes and TapeAlert flagsSET CAPACITY command Error Usage pageERASE commands rejected Re-writing media labelsUnique media identifier Using CM to check tape integrityBehavior with a missing or inconsistent EOD value Barcode support Responding to Cartridge Memory dataLoad count RWW retry counts Corrective actionDetecting the drive’s speed 4 Factors affecting performanceWays of optimizing performance Ensuring the recommended minimum transfer sizesTime-out values Using Cartridge Memory instead of tape headersUsing the Performance Log page for diagnosing problems Media type identificationHost-related factors Recommended support of log pagesFactors affecting performance where possible or a reasonably sized RAID system. More disks means ExampleRecommendation makes sense to split heavily used FC cards across separate PCI bussesDrive-related factors Do not interleave write commands with other commands, such as READFormat-related factors Page 34 Factors affecting performance Automation interface 5 Supporting Ultrium featuresCartridge Memory LTO-CM Further informationAutomation/Device Interface ADI Slave to a library controller Automation Control Interface ACIModes of usage through ACI SCSI pass-through mode ACI command setACI commands that affect drive streaming performance New features in ACI Backward compatibilitySCSI command Encryption support Recommended ACI time-out values Further detailsSupporting the ACI protocol 42 Supporting Ultrium featuresRecommended power-up sequence Treatment of reserved fieldsRecommended load-unload configuration ACI protocol communications retry Firmware upgrade via tapeRecommended Get Drive Status polling frequency Upgrading the drive firmwareLibrary firmware upgrade via tape Firmware upgrade via the primary host interfaceFirmware upgrade via ACI Handling irregular cartridgesNon-HP Ultrium 1 cleaning cartridge Cleaning cartridge HP-configured or UniversalExpired cleaning cartridge HP-configured or Universal Unreadable data cartridgeCartridge fails to seat or load Valid firmware upgrade cartridgeData cartridge with unreadable CM Cartridge cannot be loadedInvalid firmware upgrade cartridge Frequently asked questionsCleaning Is there separate firmware for drives intended to go into libraries?Resetting via the ACI Reset command Backup softwareResetting drives Resetting using the ACIRSTL lineOther mode page information Accessing Cartridge Memory without threading the tapeControlling data compression Buffer size at EW-EOMPartition size Rewind on resetWrite delay time 52 Supporting Ultrium featuresAction 6 Sense keys and codesSense keys-actions to take Console Messagelog the error, terminate I/O to the drive, and pass the appropriate “3h-MEDIUM ERROR” on page 62 . Also see the Media AccessFor additional sense codes, see “3h-MEDIUM ERROR” on error to the calling applicationAction ActionConsole Message Console MessageConsole Message End-of-Tape Additional sense codes-actions to takePhysical reached, unable to fit0h-NO SENSE 1h-RECOVERED ERROR 2h-NOT READYThe command cannot be executed because the specified The software must issue a LOAD before media accessLUN not accessible, port in 60 Sense keys and codesmechanism tests are being executed. When the tests are 62 Sense keys and codes 3h-MEDIUM ERRORA READ , SPACE , WRITE or WRITE FILEMARKS command Send a console message that an unrecovered error on and the drive. Based on this, ask the user to clean the64 Sense keys and codes Send a message to the console indicating that there is The current command such as READ, SPACE, REWIND 66 Sense keys and codes4h-HW ERROR 68 Sense keys and codes 5h-ILLEGAL REQUESTA MODE SELECT parameter list sent to the drive contains allowed to execute. In other words, some commands can 6h-UNIT ATTENTIONpersistent reservation using the PERSISTENT RESERVE OUT 32 initiators to register, using PERSISTENT RESERVE OUTAction WRITE BUFFER or MAINTENANCE OUT command service action removed all reservations and the persistentA PERSISTENT RESERVE OUT command was executed A SET DEVICE IDENTIFIER command has been successful7h-DATA PROTECTION Action 8h-BLANK CHECK related to a missing EOD data set. The most likely cause Bh-ABORTED COMMANDREAD BUFFER command 76 Sense keys and codes Dh-VOLUME OVERFLOWA WRITE or WRITE FILEMARKS command has encountered 3. Allow the user to try recovery Typical escalation procedure1. Retrieve fault information 4. Allow the user to reset devicesMonitoring the condition of the drive and media Supporting TapeAlertFlags TypePage Page Page Page Page Page Page Designing software to use the TapeAlert log TapeAlert modelsTapeAlert informational exception usage model Reading the TapeAlert logTapeAlert polling usage model Supporting OBDR One-Button Disaster Recovery OBDRResponding to the ‘Clean’ LED Providing pass-through mode Requirements for drivers and logical device managersGlossary see ”read-while-write” Index Page Page HP restricted