We back up to a Dell MD3200 with twelve 2tb nearline sas drives in raid6, refs 64k. Backup performance is totally fine, but "fast clone" performance is anything but fast.
We have synthetic full set to run on Fridays, so it has 5 backups to inject into the synthetic full and change into rollbacks. The transformation takes 7.5 hours! Shouldn't this be significantly faster?
I've noticed that b&r will run up to 3 transformations at once, even though the repository is set to only allow one action at a time.