Can I remove @img_bkp_cache generated by Hyper Backup in Synology?

Question

I have a Synology with 2 To of disk space, and it is saved every day by Hyper Backup (with Smart Recycle).

But there is a file @img_bkp_cache that is growing, and takes almost 1/5th of the total disk capacity :

368G /volume2/@img_bkp_cache
1.3T /volume2/Samba

Is it safe to remove that cache file? How to do that? What can I do to shrink it otherwise?

Thank you for your help.

Answer 1

Here is Synology support answer (translated):

The cache image contains your remote backups index. This index is compared to the remote index to figure out which elements have changed. If you have several remote backups, then @img_bkp_cache will get bigger and bigger.

The index takes roughly 5% of the total size of a backup.

It is not really safe to remove @img_bkp_cache. If you do so, the remote backup will not be affected, but it will be impossible to manage incremental backups.

In a nutshell, this file is important and cannot be deleted without consequences.

Note: Finally, I switched from RAID 1 to RAID 5 and doubled my storage capacity (I had a fifth volume that was unused), which "solved" the problem.