VSS SqlWriter issue

[gdube413]

Hi all,
Sorry for the lack of precise error logs, I'm just going by memory at the moment.

I've hit an error during the backup of a VM on which Guest OS Processing is enabled.
In the logs of the backup job, it says "Unfreeze error".

It's related to the VSS SQL Writer within the VM, but what's odd is that in the SQL Writer logs, the error specified is "Unable to open physical file" for a mdf that doesn't exist on disk, but the path of the mdf is located within the data directory of an application (FactoryTalk View).

The VM has a SQL Express instance, but all databases listed within are working and their data and log files are located in the default location (MSSQL\Data) of the SQL Server instance.

Within the data directory of the FactoryTalk View app, I cannot find the missing .mdf specified (its path includes a folder named "_bak") in the SQL Writer logs, but I can find a .mdf in another sub folder. I have a theory that perhaps the FactoryTalk View app manages its own connection (somehow?) to these .mdf files, but then how would the VSS SQL Writer be aware of these mdf files?

I've noticed that you can specify DB Exclusions to Veeam (https://www.veeam.com/kb2110), but I don't know what would be the name of these problematic databases.
Is there a way to force Veeam to list the database names it finds via VSS in a log file somewhere?

[PetrM]

Hi Guillaume,

Please provide a support case ID as requested when you click New Topic. We cannot troubleshoot technical issues over the forum posts and topics without case ID will be deleted by moderator.

At first sight, it seems that the issue does not come from our code but rather provoked at the level of SQL Writer itself. Probably, you could reproduce the same behavior without Veeam, for example by manual creation of shadow copy. Also, you may try to find some relevant detailed information in vsstrace log but from my point of view it would be best to leave this task to our support engineers.

Thanks!

[gdube413]

Hi PetrM,
I'll try debugging it first with your links, see if I can figure this out.
Thank you!

[perjonsson1960]

This thread sure left us hangin'...

What happened with the trace? Did it show anything useful?

We have a similar issue now with a VM running an SQL Express, and every backup we get the warning "SQL VSS Writer is missing: databases will be backed up in crash-consistent state". We have restarted the VM, but to no avail. We are backing up the VM with Application Aware, Copy Only. We have several other VMs with a similar configuration, and there are no problems with them. Any heads-ups?

We are running B&R 11.0.1.1261 P20211123

PJ