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VEEM 6.5.0.109 Backup failure (DC and Exchange VMs)

Hi,

I have a daily backup job that has been failing this week. I'm new in the job so want to get this sorted as soon as possible.

The backup job backs up numerous VMs on the estate but the job is failing due an issue backing up the DC and the Exchange servers.

The error log reads:

Exchange servers (both of them with the same error:

Failed to prepare guest for hot backup. Error: RPC function call failed. Function name: ISsnapshot in progress) Target machine x.x.x.x. RPC error, The RPC server is unavailable. Code 1722. Error: RPC function call failed. Function name: (ISSnapshotinprogress). Target machine x.x.x.x. RPC error. The ROC server is unavaialble. Code 1722

DC:

Unable to release guest. Unfreeze error. (backup job failed. Cannot create a shadow copy of the volumes containing writers data. A VSS critical writer has failed. Writer name: NTDS (class id xxxxxxxxxxx) Writer state (VSS_WS_failed_at_post_snapshot. Error code (0X800423F4). Error: unfreeze error (backup job failed. Cannot create a shadow copy of the volumes containing written data. A VSS critical writer has failed. Written name (NTDS) VSS_WS_FAILED_AT_POST_SNAPSHOT_ERROR Code (0X800423F4)

Looking forward to the replies and thanks.

Hypercat (Deb)

If you can, I would first try a simple restart on both of those machines. The VSS error might be resolved, at least temporarily, by checking the status of the VSS writers on that server and restarting the NTDS writer if it's not running.

Dave Smith

ASKER

Hello, thanks for the reply. I should've said I have already rebooted the servers but the backup continued to fail.

Hypercat (Deb)

Did you check the VSS writers after the restart and was the NTDS writer running?

Dave Smith

ASKER

I didn’t check them as I don’t know what they are. Can you please tell me how to check these settings?

Hypercat (Deb)

Sure - VSS Writers are used during backups of certain types of data so that the backup can be performed even when the service/program is active. They are a common source of backup errors.

You need to log on to the server and open an administrative command prompt. In the prompt type:

vssadmin list writers

You should see a list with items that look similar to this:

Writer name: 'WMI Writer'
Writer Id: {a6ad56c2-b509-4e6c-bb19-49d8f43532f0}
Writer Instance Id: {9ae6e9e1-ae3f-42ef-bcdb-19fdefcf51d6}
State: [1] Stable
Last error: No error

Writer name: 'NTDS'
Writer Id: {b2014c9e-8711-4c5c-a5a9-3cf384484757}
Writer Instance Id: {1f3b4b9a-a47a-435b-b011-0d8a12452f95}
State: [1] Stable
Last error: No error

Writer name: 'DFS Replication service writer'
Writer Id: {2707761b-2324-473d-88eb-eb007a359533}
Writer Instance Id: {5edecb8a-bffa-42bc-96d2-a6ff5101defd}
State: [1] Stable
Last error: No error

Writer name: 'IIS Metabase Writer'
Writer Id: {59b1f0cf-90ef-465f-9609-6ca8b2938366}
Writer Instance Id: {e626252e-200b-4116-8212-4f31f7f1e8c6}
State: [1] Stable
Last error: No error

The specific items will differ depending on what's running on the server. For example, on your Exchange server you should see:

Writer name: 'Microsoft Exchange Writer'
Writer Id: {76fe1ac4-15f7-4bcd-987e-8e1acb462fb7}
Writer Instance Id: {aee88408-3280-4b84-9cc4-5fe77b30b264}
State: [1] Stable
Last error: No error

The important thing is that you should see a State: [1] Stable and Last error: "No error" on all of the writers. If any of them shows a State of Failed, you need to find out why by checking the Last error field and/or by looking in the event logs.

I also found this article about this particular error related to Veeam; don't know if it will be useful to you:

https://www.veeam.com/kb1697

Dave Smith

ASKER

Thanks for this. I presume that this VSS fix concerns the DC backup failure? So I have to do something else to get the Exchange servers to work?

Hypercat (Deb)

Yes. The NTDS (NT Directory Service) error is specifically related to Active Directory of course.

Hypercat (Deb)

And the Exchange Writer is necessary to backup Exchange databases while they are online. Similarly if you have a SQL server, you will see a SQL Writer on that machine.

Dave Smith

ASKER

Hello, apologies for the delay in responding.

I ran vssadmin list writers on the DC and found that under the writer name 'NTDS':
State: Failed
Last Error: Non-Retry-able Error.

I've scheduled to reboot the DC this week. Can I restart the Active Directory Domain Service instead of a full reboot?

Hypercat (Deb)

No, you need to do a reboot to restart the VSS writers properly

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Hypercat (Deb)

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Dave Smith

ASKER

Thanks again.

Yes they are both running server 2008.

Dave Smith

ASKER

The Exchange server did not have any VSS errors when the VSS cmd was run.

Dave Smith

ASKER

Hello

I rebooted the server.

Ran vssadmin list writers - VSS NTDS was stable and was not in an error state.

Ran job but it failed with the same error.

Ran vssadmin list writers - the VSS NTDS was in error.

Ran diskpart - automount - the aotomatic mounting of the drives is enabled.

Deleted .bak files in the registry in the following reg area: HKLM\Software\Microsoft\Windows NT\CurrentVersion\ProfileList

Rebooted the server.

Ran vssadmin list writers - NTDS VSS was stable and was not in an error state.

Re-ran job and it failed.

I think I'll close this thread and open a new one as you have helped me to this point.