Recently I was troubleshooting a Veeam backup issue for a client who is utilizing the Always-On SQL architecture in their environment. The client was receiving the following error when trying to backup any of their Always-On SQL instances:
“Failed to freeze guest, wait timeout”
Note that the backup jobs started failing right after migrating the client’s vCenter databases across to the Availability Groups hosted on the Always-On SQL instances.
The only bit of literature I could find on backing up AlwaysOn SQL instances was in this (not very helpful) Veeam guide.
So I’ve dug a little deeper and found this Veeam KB article, which suggests the issue maybe with the vCenter database failing to be excluded from Application-Aware image processing.