I have been dealing with an issue where a Veeam backup copy job is not running periodic compaction of the full backup file. In my case I need the compaction to run in order for the full backup file to be re-aligned to the ReFS block size to allow fast clones to work. The fix is as follows:
1. Create the following registry key:
Registry path: HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam Backup and Replication\
Name: BackupCopyJobForceCompact
Type: REG_DWORD (0 False, 1 True)
Default value: 0 (disabled)
Please set the decimal value to '1'
2. Restart the "Veeam Backup Service" service
3. Once the compact has completed, disable the registry key by changing the value to 0.
4. Restart the "Veeam Backup Service" service
Monitor the job to make sure the periodic compaction happens normally if required (or re-configure the job to disable the periodic compaction).