VSSControl: Failed to prepare guest for freeze, wait timeout

[singy2002]

Hi,
I have an issue which is not related to Veeam only.

Since yesterday 2 seperate VSS backups, on different backup servers began failing, in both instances the error is the same (in title) I have also tried creating a VMware snapshot from the GUI selecting quiesce guest file system, which also times out. This suggests the issue with the Microsoft VSS writer.

Within the guest OS on both servers when trying to query the VSS writers there is no output. (vssadmin list writers) the command just hangs. This points to it being an OS issue.

I have checked the following.

Windows Updates (None installed a week prior to the issue first occuring)
I have found some articles suggesting DCOM permissions - not valid in these instances
Restart of VSS Service
Restart of Server
Change timeout for VSS from default 900 (Changed to 1200 as test)

All result in the same backup failure.

I have not logged a ticket as it is not down to Veeam, but wanted to post it here in case anyone has experienced this or has some suggestions.

Thanks
Andy

[Vitaliy S.]

Hi Andrew,

Do you have any VSS-related errors in the Windows Event log for this machine?

Thanks!

[singy2002]

In Application Event Log:

Volume Shadow Copy Service error: Unexpected error querying for the IVssWriterCallback interface. hr = 0x80070005, Access is denied.
. This is often caused by incorrect security settings in either the writer or requestor process.

Operation:
Gathering Writer Data

Context:
Writer Class Id: {e8132975-6f93-4464-a53e-1050253ae220}
Writer Name: System Writer
Writer Instance ID: {c83825fd-cb4c-4429-bed0-ac3f53f29ee1}

In System Event log:

I see the following.

VeeamVSS installed in system
VeeamVSS started
Application Experience started

15 minutes later.

VeeamVSS stopped
Application Experience stopped

[Vitaliy S.]

Do you have anything in common between these VMs? Have you recently installed any new applications (antivirus software) on these VMs?

I have made a quick search on your error message and found that a similar problem has been discussed on the Microsoft forums, might help:
http://answers.microsoft.com/en-us/wind ... e3f4019ebb

[singy2002]

Hi Vitaliy,

I had already seen that forum post and while it looks to be similar the two servers with the issue are completly different.

One has McAfee installed, but not that version or type and other does not. I have compeltely uninstalled AV in case that had some basis, but the situation has not changed.

The servers are as follows.

Server1
2008 R2 SP1
AD/DHCP/DNS/DFS

Server2
2008 R2 SP1
Sharepoint Foundation
SQL 2008 R2 Express

[Vitaliy S.]

Hmm...In this case I would start troubleshooting this issue from looking closer into VSS writers themselves. Windows Events Log should have more info in this:

Within the guest OS on both servers when trying to query the VSS writers there is no output. (vssadmin list writers) the command just hangs.

Also if you could involve Microsoft support team into this that would help a lot.

BTW - can you please check VSS writers on one of the available successful restore points? Do you have the same behavior?

P.S. You can use On-Demand sandbox to isolate your Exchange Server from production network for these tests.

[singy2002]

I am on the phone the with MS at the moment. I will feedback what they say.

Thanks for the help.

[mcz]

I have made a quick search on your error message and found that a similar problem has been discussed on the Microsoft forums, might help:
http://answers.microsoft.com/en-us/wind ... e3f4019ebb

Just had exactly the same issue but when I added the user to the registry (as mentioned in the microsoft article) indexing was successful. I have no idea why all of a sudden this problem occured...