HP LTO 4 SCSI, LTO 4 FC, LTO 4 SAS manual Factors affecting performance, HP restricted

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34 Factors affecting performance

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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 Inquiry string recovery 2 Configuration and initializationOperating system drivers 16 Configuration and initialization ExampleSCSI protocol, regardless of transport or interface type Enabling additional LUN support Support for additional LUNSupporting additional LUNs 18 Configuration and initialization 3 Use of tapes Using Cartridge Memory attributesUsing MODE SENSE LTO cartridge memoryFinding the remaining capacity Tape status and capacityInterpreting Log Sense data Command descriptor block Using the SET CAPACITY commandCDB fields 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 labelsBehavior with a missing or inconsistent EOD value Using CM to check tape integrityUnique media identifier Load count Responding to Cartridge Memory dataBarcode support 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 identificationFactors affecting performance Recommended support of log pagesHost-related factors 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 Modes of usage through ACI Automation Control Interface ACISlave to a library controller ACI commands that affect drive streaming performance ACI command setSCSI pass-through mode 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 A READ , SPACE , WRITE or WRITE FILEMARKS command 3h-MEDIUM ERROR62 Sense keys and codes 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 A MODE SELECT parameter list sent to the drive contains 5h-ILLEGAL REQUEST68 Sense keys and codes 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 READ BUFFER command Bh-ABORTED COMMANDrelated to a missing EOD data set. The most likely cause A WRITE or WRITE FILEMARKS command has encountered Dh-VOLUME OVERFLOW76 Sense keys and codes 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 polling usage model Reading the TapeAlert logTapeAlert informational exception usage model Responding to the ‘Clean’ LED One-Button Disaster Recovery OBDRSupporting OBDR Providing pass-through mode Requirements for drivers and logical device managersGlossary see ”read-while-write” Index Page Page HP restricted