Ok, I did a backup with both restic and borg.
Versions used
- restic: 0.9.5 compiled with go1.12.2 on linux/amd64
- borg: 1.1.9
Backup size
I forgot two subvols but backup-ed 20 btrfs subvols and /boot and /boot/efi. Size of data to backup was: 1259GiB
I should add that both repositories are on an external USB HD.
Elapsed time
- restic: 5h:21m:21sec
- borg: 7h:27m:28secs
Size of repositories
- restic: 1054GiB
- borg: 950GiB
So we have a savings of approx. 104GiB.
I will do a second round of backup to see how the elapsed times will be.
Second run
- restic: 10m:01.86s
- borg: stopped after 1.5h. It seems there is a bug and it is re-adding all files