This article explains the cause and solution of the error: STC failure occurred mid transfer - The destination volume too small.
This error happens when disks have been recently re-sized, and the sparse image does not have enough space.
1. Ensure the latest versions of ShadowProtect and ShadowSnap are installed. If not, please see the following for the download process:
2. If the disk and/or the volume has increased for the agent, remove the full image for the re-sized volume.
3. Delete the sparse image from the web interface of the device.
- Go to the web interface for the device.
- Under the Protect tab, select Configure Agent Settings.
- Select Advanced Settings followed by Volume Level Backup Control.
- Now, delete the volume that was recently re-sized. There will be a warning: click OK to continue.
- Once complete, Force a Differential Merge.
- Last, run a backup for the agent to do the differential merge.
4. Next you must delete the agent's full sparse image (i.e: all the volumes). In the web interface, select Advanced Options for the agent, and select Destroy Live Dataset. This will delete the full image of the agent, but have the same functionality with the old snapshots and the old live dataset
If this issue continues to persist, please contact Datto Technical Support for further assistance.