HP LTO 4 SAS One-Button Disaster Recovery OBDR, Responding to the ‘Clean’ LED, Supporting OBDR

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One-Button Disaster Recovery (OBDR)

5.Optionally, automate the recommended recovery actions if there are multiple tape drives or autoloaders present.

For example, the application could perform a cleaning cycle in response to flags 20 (Clean Now) and 21 (Clean Periodic). It could perform a tape copy for flags 4 (Media performance degraded) and 7 (Media life expired), and then retire the suspect tape cartridge.

This provides an opportunity for applications to add value to the TapeAlert capability of the drives.

Supporting OBDR NOTE: An application must not fail a backup job as a result of TapeAlert information. It should use the information as a preventative measure, taking action to avoid failure, or encouraging the user to take action. It should also retain the log information to help in diagnosis if a job does eventually fail.

One-Button Disaster Recovery (OBDR)

Responding to the ‘Clean’ LED NOTE: FC drives and drives in libraries do not support OBDR.

All HP Ultrium parallel-SCSI products support HP’s One-Button Disaster Recovery (OBDR) technology. This provides the fastest possible, one-step approach to regenerating a single server without using additional floppy disks or CD-ROMs.

For a general overview, see “OBDR and CD-ROM Emulation” in Chapter 1, “Ultrium Features”, of Background to Ultrium Drives, Volume 6 of the HP Ultrium Technical Manual. For details of the SCSI implementation, see “CD-ROM Emulation” in Chapter 1, “Interface Implementation”, of SCSI Interface, Volume 3 of the HP Ultrium Technical Manual.

For details of how to use OBDR see the appropriate User’s Guide.

To identify whether the firmware supports OBDR, look for the string $DR-10 in bytes 43–48 of the Inquiry data.

Supporting OBDR

The OBDR implementation in HP Ultrium drives is functionally identical to that in DAT/DDS, so no additional design or coding should be required in order to support it. The only effort needed should be in software testing.

Responding to the ‘Clean’ LED

Manual background NOTE: HP recommends that software applications use the TapeAlert log, which should mean that potential tape or cleaning problems are flagged and corrected before the drive ever reaches the point of displaying the ‘Clean’ LED.

If during normal operation, the drive detects an excessive number of RWW retries, the ‘Clean’ LED is lit. If this happens, a user should follow this procedure:

HP LTO Ultrium 4 drives technical reference manual, volume 2: software integration 89 HP restricted

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Contents LTO 4 FC, SCSI and SAS drives volume 2 software integrationHP LTO Ultrium tape drives technical reference manual HP restrictedLegal and notice information 1 Designing backup applications Contents2 Configuration and initialization 3 Use of tapes4 Factors affecting performance 5 Supporting Ultrium features7 Exception handling 6 Sense keys and codesHP restricted Documentation map Related documentsDocuments specific to HP Ultrium drives Drives-generalOperation Installation and configurationCartridges InterfaceDealing with errors Maintenance and troubleshootingGeneral documents and standardization LTO Ultrium featuresNon-immediate commands 1 Designing backup applicationsOptimizing performance Large data transfer sizeManaging the use of tapes Cleaning tape headsInformation in Cartridge Memory Monitoring tape useDiagnostic logs Design goals for LTO backup applicationsTapeAlert 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 Using MODE SENSE Using Cartridge Memory attributes3 Use of tapes LTO cartridge memoryInterpreting Log Sense data Tape status and capacityFinding the remaining capacity CDB fields Using the SET CAPACITY commandCommand descriptor block WORM media Changes to SCSI commandsHow WORM media works New additional sense codes and TapeAlert flagsERASE commands rejected Error Usage pageSET CAPACITY command 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 Corrective action RWW retry countsWays of optimizing performance 4 Factors affecting performanceDetecting the drive’s speed Ensuring the recommended minimum transfer sizesUsing the Performance Log page for diagnosing problems Using Cartridge Memory instead of tape headersTime-out values Media type identificationHost-related factors Recommended support of log pagesFactors affecting performance Recommendation Examplewhere possible or a reasonably sized RAID system. More disks means makes sense to split heavily used FC cards across separate PCI bussesDo not interleave write commands with other commands, such as READ Drive-related factorsFormat-related factors Page 34 Factors affecting performance Cartridge Memory LTO-CM 5 Supporting Ultrium featuresAutomation interface 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 Backward compatibility New features in ACISCSI command Encryption support Supporting the ACI protocol Further detailsRecommended ACI time-out values 42 Supporting Ultrium featuresTreatment of reserved fields Recommended power-up sequenceRecommended load-unload configuration Recommended Get Drive Status polling frequency Firmware upgrade via tapeACI protocol communications retry Upgrading the drive firmwareFirmware upgrade via ACI Firmware upgrade via the primary host interfaceLibrary firmware upgrade via tape Handling irregular cartridgesExpired cleaning cartridge HP-configured or Universal Cleaning cartridge HP-configured or UniversalNon-HP Ultrium 1 cleaning cartridge Unreadable data cartridgeData cartridge with unreadable CM Valid firmware upgrade cartridgeCartridge fails to seat or load Cartridge cannot be loadedCleaning Frequently asked questionsInvalid firmware upgrade cartridge Is there separate firmware for drives intended to go into libraries?Resetting drives Backup softwareResetting via the ACI Reset command Resetting using the ACIRSTL lineControlling data compression Accessing Cartridge Memory without threading the tapeOther mode page information Buffer size at EW-EOMWrite delay time Rewind on resetPartition size 52 Supporting Ultrium featuresSense keys-actions to take 6 Sense keys and codesAction Console MessageFor additional sense codes, see “3h-MEDIUM ERROR” on “3h-MEDIUM ERROR” on page 62 . Also see the Media Accesslog the error, terminate I/O to the drive, and pass the appropriate error to the calling applicationConsole Message ActionAction Console MessageAction Physical Additional sense codes-actions to takeEnd-of-Tape reached, unable to fit0h-NO SENSE 2h-NOT READY 1h-RECOVERED ERRORLUN not accessible, port in The software must issue a LOAD before media accessThe command cannot be executed because the specified 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 and the drive. Based on this, ask the user to clean the Send a console message that an unrecovered error on64 Sense keys and codes Send a message to the console indicating that there is 66 Sense keys and codes The current command such as READ, SPACE, REWIND4h-HW ERROR 68 Sense keys and codes 5h-ILLEGAL REQUESTA MODE SELECT parameter list sent to the drive contains persistent reservation using the PERSISTENT RESERVE OUT 6h-UNIT ATTENTIONallowed to execute. In other words, some commands can 32 initiators to register, using PERSISTENT RESERVE OUTAction A PERSISTENT RESERVE OUT command was executed service action removed all reservations and the persistentWRITE BUFFER or MAINTENANCE OUT command 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 1. Retrieve fault information Typical escalation procedure3. Allow the user to try recovery 4. Allow the user to reset devicesSupporting TapeAlert Monitoring the condition of the drive and mediaType FlagsPage Page Page Page Page Page Page TapeAlert models Designing software to use the TapeAlert logTapeAlert informational exception usage model Reading the TapeAlert logTapeAlert polling usage model Supporting OBDR One-Button Disaster Recovery OBDRResponding to the ‘Clean’ LED Requirements for drivers and logical device managers Providing pass-through modeGlossary see ”read-while-write” Index Page Page HP restricted