I am experiencing a problem with Windows Server Backup where previous backup versions (copies) are lost if the connection to the iSCSI target, where the backups are stored, is dropped and remains disconnected for a short time.
I have configured the Windows Server 2008 server to connect to a QNAP iSCSI NAS device using the built in iSCSI Initiator. I have also configured Windows Server Backup to use the iSCSI volume as the backup target disk. Periodically, for reasons not yet understood, the server loses connectivity with the iSCSI device. When this happens I often find that the backup copies that had existed on the target volume are no longer there and the backups have to start again.
Today I discovered that the volume ID of the target disk seems to change, without manual intervention, when the iSCSI initiator reconnects to the target and Windows Server Backup is refreshed. This is demonstrated by the output of the WBADMIN GET VERSIONS command, e.g.:
Backup time: 18/05/2011 23:30
Backup target: Fixed Disk labeled ATEGO-M 2010_03_17 08:29 DISK_01(\\?\Volume{a79ff0ae-2cbb-11df-8798-005056bb11b1})
Version identifier: 05/18/2011-23:30
Can Recover: Volume(s), File(s), Application(s), Bare Metal Recovery, System State
Backup time: 19/05/2011 23:30
Backup target: Fixed Disk labeled ATEGO-M 2010_03_17 08:29 DISK_01(\\?\Volume{a79ff0ae-2cbb-11df-8798-005056bb11b1})
Version identifier: 05/19/2011-23:30
Can Recover: Volume(s), File(s), Application(s), Bare Metal Recovery, System State
Backup time: 20/05/2011 23:30
Backup target: Fixed Disk labeled ATEGO-M 2010_03_17 08:29 DISK_01(\\?\Volume{a79ff0ae-2cbb-11df-8798-005056bb11b1})
Version identifier: 05/20/2011-23:30
Can Recover: Volume(s), File(s), Application(s), Bare Metal Recovery, System State
Backup time: 14/11/2011 10:53
Backup target: Fixed Disk labeled ATEGO-M 2011_05_22 13:08 DISK_01(\\?\Volume{32077493-83cc-11e0-931b-005056bb11b1})
Version identifier: 11/14/2011-10:53
Can Recover: Volume(s), File(s), Application(s), Bare Metal Recovery, System State
Backup time: 23/12/2011 20:34
Backup target: Fixed Disk labeled ATEGO-M 2011_11_14 17:43 DISK_01(\\?\Volume{c253b27d-0dd8-11e1-bab4-005056bb11b1})
Version identifier: 12/23/2011-20:34
Can Recover: Volume(s), File(s), Application(s), Bare Metal Recovery, System State
Backup time: 30/01/2012 09:20
Backup target: Fixed Disk labeled ATEGO-M 2011_12_24 10:41 DISK_01(\\?\Volume{62330671-2d51-11e1-b23e-005056bb11b1})
Version identifier: 01/30/2012-09:20
Can Recover: Volume(s), File(s), Application(s), Bare Metal Recovery, System State
You can see that the label (ATEGO-M 2011_12_24 10:41 DISK_01) remains constant throughout, but the volume GUID changes. I suspect that this causes Windows Server Backup to lose its backup history as it no longer recognises the volume as being the same - although it quite clearly is.
The question is: Is this behaviour to be expected?
Should the volume GUID change each time the volume is disconnected and reconnected?
I suspect that it shouldn't. So, is there a way to fix the GUID so that it remains constant even if the volume becomes disconnected for a short while?
Thanks
Ash