Volume does not have enough free disk space to create VSS snapshot

[brjohnson]

A backup job reported that a volume did not have enough free space to create a VSS snapshot, but I checked what was recoverable in the Guest File Restore browser, and the volume appears to be there for the job that produced the alert. I know VSS is necessary for Application-Aware processing, but this job does not have that configured.

What, specifically, is lost when Veeam is unable to create VSS snapshots?

[Vitaliy S.]

Hi Brett,

VSS snapshot is required to have a consistent backup state. If you're running highly transactional applications in these VMs, then some operation might have been lost.

Thanks!

[Nas]

Hi Vit,
As the agent backup job still finished with success/warning when Veeam says Volume (C:) does not have enough free disk space to create VSS snapshot, so Veeam can still create crash consistent backup without VSS snapshot, just that it wont be application/transaction consistent backup, right?

[Dima P.]

Hello Nas,

A bit confused - your post is in Hyper-V forum but you are asking about agent backup...

Veeam Agent for Window cannot work without VSS and there is no such thing as crash consistent backup, so free space for VSS is a mandatory system requirement for Operating System. VM backup job can take crash consistent backup if you configure the job accordingly. Thank you!