CSV Backup Problem

[noesberger]

Hello

Today I installed veeam to backup our Hyper-V Test Cluster. All our VM's are stored on a CSV Volume.

When I backup a single machine it works fine. When I backup 2 machines at a same time, VM's on my cluster are getting a bluescreen.
I think it's because during the backup the CSV Volumes are in redirected mode, because I can't use VSS Hardware Providers. When then the 2nd backup starts, the Cluster has a problem.

Does anybody else have the same problem. How is veeam solving this problem when VSS Hardware Providers can't be used?

Thanks for your help.

[foggy]

Hi,

If hardware provider cannot be used, then software VSS provider is used for volume snapshot. Second VM backup would then wait until the first one is backed up and snapshot is removed (software VSS only supports 1 snapshot per volume). So, this situation should be handled correctly, there were no issues observed by beta customers.

How did you add your Hyper-V server into Veeam B&R console? Did you add it as a cluster or a standalone server?

Thanks!

[noesberger]

I've added the servers as a Cluster. I added the clustername and veeam has read automatically the information about the hosts.

I've also some other problems:
- When the backup starts it generates vss errors on the hyper-V host.
(Error 8194, Volume Shadow Copy Service error: Unexpected error querying for the IVssWriterCallback interface. hr = 0x80070005, Access is denied)
- During the backup the following warning appears (Unable to use changed block tracking, CTP changes table is not loaded)
but a *.ctp file starting with the hostsname exists on the CSV Volume..

[foggy]

I would suggest then to log a support call on this to let them see the logs as the problem might lie a bit deeper. Thanks.

[abigot@serians.fr]

hello,
I've the same problem (error Error 8194, Volume Shadow Copy Service error: Unexpected error querying for the IVssWriterCallback interface. hr = 0x80070005, Access is denied)
; dis you solve this issue ?
regards,
Arnaud Bigot

[foggy]

Arnaud, the OP haven't updated this topic with the resolution and I also cannot get any valuable information from the e-mail thread related to his support case. So I would suggest you to open another one for your own investigation. Thanks!

[Gostev]

When I backup 2 machines at a same time, VM's on my cluster are getting a bluescreen.

Does this look like your issue then?
http://support.microsoft.com/kb/2494162

[abigot@serians.fr]

hi Gostev,
I found out the problem (error 8194...IVssWriterCallback...) on Hyper-V host when backing up VMs on a CSV :
Go to DCOM setup : dcomcnfg --> Expand Component Services, Computers --> Right-click My Computer --> Properties --> COM Security tab.
Under Access Permission click Edit Default. --> add the "Network Service" account with Local Access allowed.
Restart the computer !
no more 8194 error.

as for the CBT error (in Veeam log I had “failed to flush file changes”, or “failed to call RPC function ‘HvCtpFlushChanges’…)
I think the problem was caused after adding a *.vhd to a VM without modifying Veeam job (I should have "recalculate" VM size in Veeam job before launching backup again.)

[Gostev]

Great, thanks for posting the resolution!

[jldwyer1420]

this didn't work for me. any other suggestions?

[Vitaliy S.]

Jeff, I think it might the right time to let our support team investigate your issue.

[jldwyer1420]

The support tech had me disable CBT. Issue seems to be fixed, without CBT enabled.

[Gostev]

This is unacceptable resolution/workaround though...

[markharford]

Getting a similar issue with CBT no longer working in a backup job where it previously worked.

20/04/2012 02:04:11 :: Unable to use changed block tracking. CTP changes table is not loaded. The system cannot find the file specified

I also get the following in the event log when the job starts:

Code: Select all

[i]Log Name:      Application
Source:        VSS
Date:          20/04/2012 02:01:15
Event ID:      8194
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Description:
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: {f55ba41e-1d0d-4638-af70-4a9444f30dd6}[/i]

I've added the DCOM permissions as suggested but will have to wait till weekend to see if it helps.

[markharford]

Just to update this topic - The issue I experienced was fixed as part of Job ID#5184155 with a post-patch 3 update.

[jldwyer1420]

how can i get this post-patch 3 update?

[Gostev]

Hi Jeff, all hotfixes can be obtain by contacting our technical support.