If I realized correctly, UrBackup defaults to no redundacy because of forced use of file level deduplication (by means of hard links). What ways of redundancy (except RAID which already there) are possible? Does Full backup can be tweaked to make redundant copies of all (even identical) files?
(Using UB on Centos 7.8)
No. It is the responsibility of the operating system and hardware to ensure that files saved by UrBackup are returned in the same condition when requested. There is a discussion in the Administration Manual in Section 11.6 regarding Suitable file systems.
There are also many messages in this forum regarding backing up the UrBackup server for disaster recovery.
IMHO a supplementary switch to turn off hard linking for full backups coudn’t do harm, is not that right?
That would fill your storage very fast…
Using current UrBackup technology the full backup has barely noticeable difference from incremental one. It’s kind of “allways synthetic full” regardless backup action type chosen. Vanilla full backup IMHO could be full in the sense of the word. You can adapt to present storage limits by scheduling and retention policy.
Backup is allways about “wasting” storage space.
I run two separate machines. Each one running a copy of the server. One or both machines could be virtual. I then point each client to backup to both servers. I can restore a client from either server. Redundancy.
I back up the backup server’s data. That way, even if something happens to the backup server itself AND the backed up machines, I still have the data. If you do this off-site, you effectively have a very cost efficient 3-2-1 solution.