HP LTO 4 FC Using CM to check tape integrity, Behavior with a missing or inconsistent EOD value

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application to locate the tape in preparation for subsequent writing or reading operations. At the start of an appending archive or backup session, it is common for the application to locate the tape to a logical position immediately preceding the second filemark and to overwrite the second filemark during the data appending session.

Writes are allowed:

•when the current logical position is at EOD. This means that the drive must have read the EOD from tape before attempting to overwrite it.

•when there are only filemarks between the current logical position and EOD, and at least one filemark immediately before the current logical position.

Using CM to check tape integrity

Drives that support WORM cartridges check that the anti-tampering measures have not been violated before and during media access operations. If a violation is detected, for example, if the content of the CM does not match the content of the tape, the cartridge is treated as read-only, and Tape Alert flag 3Bh (WORM medium—integrity check failed) is set.

HP strongly recommends that software applications check for the presence of TapeAlert flag 3Bh after a tape load and periodically during operation. If the flag is set, the software should alert the operator and log the incident for audit.

Hosts can use the WTRE bit on the Device Configuration mode page (bit 6, byte 15 of mode page 10h) to control the behavior of the drive when reading WORM media whose WORM integrity is in doubt and which may have been tampered with. See details of the mode page in Chapter 4 in SCSI Interface, volume 4 of the HP LTO Ultrium Technical Reference Manual for more information.

Behavior with a missing or inconsistent EOD value

A missing EOD value or one in which the value on tape differs from that in CM can be caused by:

•CM corruption

•deliberate, malicious alteration of the EOD value in the CM

•an interruption of the drive power supply while writing data.

If the CM indicates that the EOD is not valid (for example, if the drive has powered down during a write), TapeAlert flag 04h (Media) will be set on cartridge load.

The drive behaves as for a RW cartridge with no EOD data set, except that any attempt to overwrite data will be rejected with CHECK CONDITION, a sense key of Data Protect and additional sense of 2700h (write-protected). Tape Alert flag 09h (Write-Protect) is set.

Unique media identifier

For added security, HP strongly recommends that applications read and track cartridge manufacturer and serial number values from the Cartridge Memory using MAM access commands:

•Attribute ID 0x0400: Cartridge manufacturer ID

•Attribute ID 0x0401: Cartridge serial number

Both values should be read and concatenated to ensure that the number is unique.

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Contents volume 2 software integration LTO 4 FC, SCSI and SAS drivesHP LTO Ultrium tape drives technical reference manual HP restrictedLegal and notice information Contents 1 Designing backup applications2 Configuration and initialization 3 Use of tapes5 Supporting Ultrium features 4 Factors affecting performance6 Sense keys and codes 7 Exception handlingHP restricted Related documents Documentation mapDocuments specific to HP Ultrium drives Drives-generalInstallation and configuration OperationCartridges InterfaceMaintenance and troubleshooting Dealing with errorsLTO Ultrium features General documents and standardization1 Designing backup applications Non-immediate commandsOptimizing performance Large data transfer sizeCleaning tape heads Managing the use of tapesInformation in Cartridge Memory Monitoring tape useDesign goals for LTO backup applications Diagnostic logsTapeAlert Displaying drive informationInclude the capability to download firmware 2 Configuration and initialization Inquiry string recoveryOperating system drivers Example 16 Configuration and initializationSCSI protocol, regardless of transport or interface type Support for additional LUN Enabling additional LUN supportSupporting additional LUNs 18 Configuration and initialization Using Cartridge Memory attributes Using MODE SENSE3 Use of tapes LTO cartridge memoryTape status and capacity Finding the remaining capacityInterpreting Log Sense data Using the SET CAPACITY command Command descriptor blockCDB fields Changes to SCSI commands WORM mediaHow WORM media works New additional sense codes and TapeAlert flagsError Usage page ERASE commands rejectedSET CAPACITY command Re-writing media labelsUsing CM to check tape integrity Behavior with a missing or inconsistent EOD valueUnique media identifier Responding to Cartridge Memory data Load countBarcode support RWW retry counts Corrective action4 Factors affecting performance Ways of optimizing performanceDetecting the drive’s speed Ensuring the recommended minimum transfer sizesUsing Cartridge Memory instead of tape headers Using the Performance Log page for diagnosing problemsTime-out values Media type identificationRecommended support of log pages Factors affecting performanceHost-related factors Example Recommendationwhere possible or a reasonably sized RAID system. More disks means 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 5 Supporting Ultrium features Cartridge Memory LTO-CMAutomation interface Further informationAutomation/Device Interface ADI Automation Control Interface ACI Modes of usage through ACISlave to a library controller ACI command set ACI commands that affect drive streaming performanceSCSI pass-through mode New features in ACI Backward compatibilitySCSI command Encryption support Further details Supporting the ACI protocolRecommended ACI time-out values 42 Supporting Ultrium featuresRecommended power-up sequence Treatment of reserved fieldsRecommended load-unload configuration Firmware upgrade via tape Recommended Get Drive Status polling frequencyACI protocol communications retry Upgrading the drive firmwareFirmware upgrade via the primary host interface Firmware upgrade via ACILibrary firmware upgrade via tape Handling irregular cartridgesCleaning cartridge HP-configured or Universal Expired cleaning cartridge HP-configured or UniversalNon-HP Ultrium 1 cleaning cartridge Unreadable data cartridgeValid firmware upgrade cartridge Data cartridge with unreadable CMCartridge fails to seat or load Cartridge cannot be loadedFrequently asked questions CleaningInvalid firmware upgrade cartridge Is there separate firmware for drives intended to go into libraries?Backup software Resetting drivesResetting via the ACI Reset command Resetting using the ACIRSTL lineAccessing Cartridge Memory without threading the tape Controlling data compressionOther mode page information Buffer size at EW-EOMRewind on reset Write delay timePartition size 52 Supporting Ultrium features6 Sense keys and codes Sense keys-actions to takeAction Console Message“3h-MEDIUM ERROR” on page 62 . Also see the Media Access For additional sense codes, see “3h-MEDIUM ERROR” onlog the error, terminate I/O to the drive, and pass the appropriate error to the calling applicationAction Console MessageAction Console Messagepage Additional sense codes-actions to take PhysicalEnd-of-Tape reached, unable to fit0h-NO SENSE 1h-RECOVERED ERROR 2h-NOT READYThe software must issue a LOAD before media access LUN not accessible, port inThe command cannot be executed because the specified 60 Sense keys and codesmechanism tests are being executed. When the tests are 3h-MEDIUM ERROR A READ , SPACE , WRITE or WRITE FILEMARKS command62 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 5h-ILLEGAL REQUEST A MODE SELECT parameter list sent to the drive contains68 Sense keys and codes 6h-UNIT ATTENTION persistent reservation using the PERSISTENT RESERVE OUTallowed to execute. In other words, some commands can 32 initiators to register, using PERSISTENT RESERVE OUTAction service action removed all reservations and the persistent A PERSISTENT RESERVE OUT command was executedWRITE BUFFER or MAINTENANCE OUT command A SET DEVICE IDENTIFIER command has been successful7h-DATA PROTECTION Code 8h-BLANK CHECK Bh-ABORTED COMMAND READ BUFFER commandrelated to a missing EOD data set. The most likely cause Dh-VOLUME OVERFLOW A WRITE or WRITE FILEMARKS command has encountered76 Sense keys and codes Typical escalation procedure 1. Retrieve fault information3. Allow the user to try recovery 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 modelsReading the TapeAlert log TapeAlert polling usage modelTapeAlert informational exception usage model One-Button Disaster Recovery OBDR Responding to the ‘Clean’ LEDSupporting OBDR Providing pass-through mode Requirements for drivers and logical device managersGlossary see ”read-while-write” Index Page Page HP restricted
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