T10000B "Triple" Cleaning of drive results in Library time out and cleaning cartridge being left in drive.

Asset ID:	1-73-1019621.1
Update Date:	2010-10-29
Keywords:

Solution Type FAB (standard) Sure

Solution 1019621.1 : T10000B "Triple" Cleaning of drive results in Library time out and cleaning cartridge being left in drive.

Impact

Library times out waiting for a triple clean to complete and sends a mount response before the cleaning operation is done.

Contributing Factors

Sun StorageTek T10000 Tape Drive when a triple clean operation occurs is impacted by this issue.

When a drive signals that it needs to be cleaned, ACSLS and HSC prefix the next mount with a cleaning operation. After ACSLS or HSC mounts the cleaning cartridge, they wait for the mount response, which the library sends when the cleaning operation is complete. HSC and ACSLS then dismounts the cleaning cartridge and mounts the requested data cartridge.

The problem is that when a triple clean is in progress, the library times out waiting for the clean to complete and sends a mount response before the cleaning operation is done. When ACSLS or HSC try to dismount the cleaning cartridge, it is still loaded, and the dismount fails. The result is several error messages in the ACSLS or HSC logs and a cleaning cartridge left in the drive. The cleaning cartridge must be manually dismounted.

This is also a problem when a SCSI/Fibre-attached library (e.g. L700) automatically cleans tape drives. Fibre-attached libraries clean the drive after the dismount. The cleaning operation is still underway when the library timeout occurs. The library tries to dismount the cleaning cartridge, but it is still loaded. This causes the library to leave the cleaning cartridge mounted in the drive.

Symptoms

T10KB drives may sometimes do triple, or aggressive cleaning. This can cause ACSLS and HSC to leave cleaning cartridges in the drive and prevent subsequent mounts to the drive. This disrupts automated tape operations and will result in several error messages in the ACSLS or HSC logs.

Root Cause

With the newest T10KB firmware (1.38.209), the T10KB drive will occasionally invoke triple cleaning cycles to address certain error conditions. This cleaning operation takes about 7 minutes. Normal cleaning takes about 3 minutes. The problem is that the library's drive controller times out after 5 minutes.

Corrective Action

Workaround:

When this occurs, manually dismount the cleaning cartridge via ACSLS or HSC.

You can also issue a "recovery move" via SLConsole to return the cleaning cartridge to its source cell.

Note: You must issue the recovery move when a Fibre-attached library does automated cleaning. This returns the cleaning cartridge to its system cell.

After dismounting the cleaning cartridge, you may need to re-issue failing mounts.

Resolution:

This will be resolved with 4.10 (and above) library firmware.

SL8500 firmware that extends the timeout for cleaning operations should be available in November, 2008. This will probably be 4.10 firmware.

Comments

This issue only affects T10KB drives, and it was introduced in 1.38.209 firmware. A special build, RA.38.209, is available which will turn off triple cleaning of drives.

For more information reference the attached document which provides a microcode change history related to this issue.

References:

BugID: 6740945

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Internal Sun Alert & FAB Admin Info
30-Oct-2008: Converted from a Problem Resolution asset in order to push to the field - sending to Extended Review.
31-Oct-2008: No feedback from Ext Rvw - sending to Publish.

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