During restores: "Error bptm error requesting media TpErrno = Robot operation failed"

Problem

Receiving "Error bptm error requesting media TpErrno = Robot operation failed" message during backup and/or restore operations.

Error Message

Activity Monitor Job Detailed Status:

Error bptm error requesting media TpErrno = Robot operation failed

Robtest returns the following error:

Initiating MOVE_MEDIUM from address 257 to 4108
move_medium failed
sense key = 0x4, asc = 0x15, ascq = 0x1, MECHANICAL POSITIONING ERROR

NetBackup bptm logs report the following errors:

05/17/2008 15:17:57 - Error bptm (pid=6297) error requesting media, TpErrno = Robot operation failed
 

Cause

Environment/Conditions:

Tape library with 10 tape drives. There is limited zoning in the SAN switch:
The HBA 20:00:00:1b:62:14:02:bd is in two different zones as shown below.

zone: ZONE_A1
20:01:00:40:7c:05:95:ee (Tape device)
20:02:00:70:7c:05:95:ee (Tape device)
20:00:00:1b:62:14:02:bd (HBA)

zone: ZONE_B1
20:01:00:50:7c:05:95:ee (Tape device)
50:00:1f:e1:50:06:4b:f8
50:00:1f:e1:50:06:4b:fa
50:00:1f:e1:50:06:4b:fc
50:00:1f:e1:50:06:4b:fe
50:00:1f:e1:50:0d:9a:38
50:00:1f:e1:50:0d:9a:3a
50:00:1f:e1:50:0d:9a:3c
50:00:1f:e1:50:0d:9a:3e
20:00:00:1b:62:14:02:bd (HBA)

Troubleshooting:

1. Running /usr/openv/volmgr/robtest in attempt to mount the tape also fails. See KB article in the Related Documents section below for more information regarding robtest.
2. Running /usr/openv/volmgr/bin/goodies/scan command shows the 3 available drives in an UP status.
3. All hwmgr commands showed only three drives with the remaining drives listed as "null".
4. The hwmgr -scan scsi did not rid the remaining "null" device paths.

Solution

Suggest engaging the device vendor and storage administrator to investigate the hardware issues.

• In this case they had to:
  • verify connectivity with the tape drives and library
  • correct the zoning to see all available tape drives.
• In another case they had to:
  • power-cycle the library, which fixed the problem.