Veeam Backup Error - 'Unable to release guest. Error: Unfreeze error:'
Problem
Yesterday morning, I walked into the office, the boss told me a client's
Exchange was running slowly and they had had a Veeam backup fail. I know this
client well enough to know if it was something simple he would have fixed it
himself, so while my laptop booted I armed myself with a coffee.
I connected to the Veeam backup server and this was the error.
Unable to release guest. Error: Unfreeze error: [Backup job failed.
Cannot create a shadow copy of the volumes containing writer's data. A VSS
critical writer has failed. Writer name: [Microsoft Exchange Writer]. Class ID:
[{76fe1ac4-15f7-4bcd-987e-8e1acb462fb7}]. Instance ID:
[{65ec880f-7b6a-402f-baf1-14d4de7f6fb9}]. Writer's state:
[VSS_WS_FAILED_AT_FREEZE]. Error code: [0x800423f2].]
Error: Unfreeze error: [Backup job failed. Cannot create a shadow copy of the volumes containing writer's data. A VSS critical writer has failed. Writer name: [Microsoft Exchange Writer]. Class ID: [{76fe1ac4-15f7-4bcd-987e-8e1acb462fb7}]. Instance ID: [{65ec880f-7b6a-402f-baf1-14d4de7f6fb9}]. Writer's state: [VSS_WS_FAILED_AT_FREEZE]. Error code: [0x800423f2].]
Error: Unfreeze error: [Backup job failed. Cannot create a shadow copy of the volumes containing writer's data. A VSS critical writer has failed. Writer name: [Microsoft Exchange Writer]. Class ID: [{76fe1ac4-15f7-4bcd-987e-8e1acb462fb7}]. Instance ID: [{65ec880f-7b6a-402f-baf1-14d4de7f6fb9}]. Writer's state: [VSS_WS_FAILED_AT_FREEZE]. Error code: [0x800423f2].]
Solution
1. OK that’s a huge error, but essentially it's complaining about
the VSS writer on the Exchange server. Log
onto the Exchange server, drop to command line and issue the following command;
vssadmin list writers
Chances are you will see the following;
Information Store (2544) Shadow copy instance 1 aborted.
2. To fix that you need to restart the Microsoft Exchange information
store service.
3. Check again to make sure you are back up.
4. Note: We are backing up using Veeam, make sure there is no instance
of the Symantec Backup Exec Remote Agent for Exchange, if it's there remove it.
5. Finally, I’ve got over 120GB of transaction logs to contend
with, for the problem mail store, I’m going to enable circular logging to free
up some room. (Note: You can disable this again once you have a decent
backup if you wish).
6. At this point I rebooted both the Exchange server and the Veeam
Backup server it then performed a backup of the Exchange server without error.
