Immutability simply sets a flag on when the files can be modified/deleted.  The retention policy will delete the files however.  If the flag has not yet expired, it’ll be marked for deletion once the flag has expired. If you’re using a smaller repo, in order to prevent yourself from running out of space, you’ll likely need to set immutability to not extend beyond what restore points you can afford to delete with the retention policies.

There is some information on how this works under the LHR (Linux Hardened Repository) section below.

https://helpcenter.veeam.com/docs/backup/vsphere/hardened_repository.html?ver=120

Hi

Buy enough storage to store your backups. Manual cleaning should never be required. A backup/backup copy job or background retention job will remove them after the backup chain has expired.

You can use our calculator for a storage estimation:

https://calculator.veeam.com/vbr/
 

Best,

Fabian

Another thing to keep in mind here is the added 10 days noted in the description on this page.  So, there will be additional immutability days on top of the selected number you choose.  Also using the calculator Mildur posted helps with calculations for sure.  Definitely a go to tool for this stuff.

I’m needing to verify my restore points as well. This is a great post for me to reference. Thanks guys!