Space not released after deleting backup chain

[tomluna]

Backup target is a HPE MSA2040, where we run a immutable storage which is mounted on an Ubuntu Server 20.04. As the target became full, I had to delete the first backup chain (about 3 TB). The files were deleted using the Veeam B&R delete function in files. But unfortunately the target is still full, no space was released after deletion. Checking for files locked by a process (lsof) gave no result and restarting all involved machines did not give the space back.
So I decided to delete another backup chain directly from the Linux machine using rm - everything fine, files deleted, space released.
Anybody here who has an idea how I can free the space of the first deleted backup chain?


Veeam Support Case: 05874630

[Mildur]

Hi Tom

Moved this topic. You don't have an Object Storage in place.

I assume your hardened repository is backed by a XFS filesystem.
With XFS, you are using FastClone technology. Meaning that all synthetic full backups share data blocks on your volume. Deleting a single synthetic full backup won't free up the space of an entire full backup. It's data blocks may be used by other full backups.

Best,
Fabian

[tomluna]

Hello Fabian,
what does this mean in my situation - am I stuck with a full backup forever as the data blocks could not be released?
Regards
Tom

[Mildur]

Hi Tom

Do you use XFS as the filesystem for the mounted storage in your Ubuntu Server?
Then yes, reclaiming storage by just deleting 1x synthetic full won't have much effect.

Maybe you can share more details:
- Are you doing active or synthentic fulls?
- How big is your entire backup storage?
- Do you use XFS or is it another filesystem?

Best,
Fabian

[tomluna]

Hi Fabian,
we use XFS as filesystem.
For the job we were doing synthentic fulls every saturday and an active full every first saturday of month (which caused the creation of a full backup on December, 31st and then again on January 7th, I think - so with this extra backup storage went full in January).
Storage is 23 TB, no space left.

Regards
Thomas

[Mildur]

Hi Tom

Active Fulls will take the entire space. And each synthetic full backup following an active full will share the same blocks with the active full. Until you create a new active full backup.
If you want to reclaim space, you must delete an active full backup and all dependent synthetic full backups. And of course do not forget about the incremental backups following this full.

I suggest to disable active full backups and only do synthetic fulls. This will solve the storage issue for future backups without buying new disks.

Best,
Fabian

[tomluna]

Hello Fabian,
we will do it the way you described.
Thank you!

Regards
Tom