HP LTO 4 SAS Re-writing media labels, Allow overwrite of last filemarks before the EOD data set

TapeAlert flags:

•3Bh (WORM medium—integrity check failed)

•3Ch (WORM medium—overwrite attempted)

Error Usage page

For WORM cartridges, the Wrap Number fields in the Error Usage page are replaced by an Error Code field. This contains the ASC/Q value reported to the host when the associated error was detected.

Only appended writes accepted

If a WORM cartridge is placed in a WORM-compatible drive, the drive will accept write commands (records, filemarks) only if the current logical position is beyond the position identified by the EOPD value. If a write command is received by the drive when the logical position is before the EOPD value, the command will be rejected and CHECK CONDITION returned with sense key of Data Protect and additional sense of 300Ch (WORM medium—overwrite attempted). The TapeAlert flags 3Ch (WORM medium—overwrite attempted) and 09h (write-protect) are set.

ERASE commands rejected

ERASE commands (short or long) to a drive containing a WORM cartridge will not overwrite or erase user data on tape. Any ERASE command that would result in user data being over-written on tape is rejected and CHECK CONDITION returned with sense key of Data Protect and additional sense of 300Ch (WORM medium - overwrite attempted). The TapeAlert flags 3Ch (WORM medium—overwrite attempted) and 09h (write-protect) are set.

SET CAPACITY command

The SET CAPACITY command will only be accepted and executed if the WORM cartridge has not been initialized, that is, it has never been written to.

If a SET CAPACITY command is received by the drive when the cartridge has been initialized, it is rejected and CHECK CONDITION returned with sense key of Data Protect and additional sense of 300Ch (WORM medium—overwrite attempted). The TapeAlert flags 3Ch (WORM medium—overwrite attempted) and 09h (write-protect) are set.

Re-writing media labels

If there is no user data on the tape, the media label can be rewritten. The label contains software application-related information such as a unique identification code and does not contain user data.

Writing is allowed when the current logical position is at BOT and:

•there are only filemarks between this position and EOD, or

•there are only 1 or 2 sequential records followed by any number of filemarks, but no further records, between this position and EOD.

Allow overwrite of last filemarks before the EOD data set

At the end of a backup or archive session, many software applications write two filemarks to tape immediately before the EOD data set is written. These filemarks are logical markers that enable the

HP LTO Ultrium 4 drives technical reference manual, volume 2: software integration 23 HP restricted