When perform a file backup up on AhsayOBM/AhsayACB v7 the job ends with "Snapshot for Shadow Copy Set is missing, backup terminate." error.

The error message is returned by the Microsoft Windows Volume Shadow Copy Service (VSS).

To support backups of volume mount points on Windows file backup sets on AhsayOBM/AhsayACB v7, if "Volume Shadow Copy" option is enabled , AhsayOBM/AhsayACB v7 will initiate a VSS snapshot of all local drives found on the machine regardless if the drive has been selected in the backup source.

This behavior different from AhsayOBM/AhsayACB v6 which only initiates a VSS snaphot of a local drive selected in the backup source.

If the client machines are not configured with volume mount points and there are persistent "[Shadow Copy] Snapshot for Shadow Copy Set is missing, backup terminate." backup errors.

As a workaround you could consider reverting the current AhsayOBM/AhsayACB v7 VSS snapshot behavior back v6, this can be done by:

1. Editing the %OBC_INSTALLL_PATH%\ cb.opt file
   
   Example:
   # Set option to true for disabling adding all volumes to shadow copy set
   com.ahsay.obx.core.backup.file.ShadowCopy.disableAddAllVolumes=true
   
   
2. Restart AhsayOBM/AhsayACB scheduler service.

VSS, Volume Shadow Copy Service, volume mount point