The "SNAPSHOT_FAILURE" alert occurs when the VSS (Volume Shadow Copy Service) snapshot fails at the host level in a Hyper-V host machine. One of the common causes for this alert is the "VSS service" being disabled on the Hyper-V host.
Solution:
To resolve the "SNAPSHOT_FAILURE" issue, follow the steps below:
1. Open "Services.msc" on the Hyper-V host machine.
2. Locate the "Volume Shadow Copy Service" and check its status.
3. If the service is disabled or stopped, start the service to proceed with the backup.
Alternatively, you can perform the following steps in an elevated command prompt window:
net stop vss
net start vss
Please note that there could be other factors leading to snapshot failures in Hyper-V VMs. Some of the other common reasons for snapshot failures are listed below: