On Sat, Oct 19, 2019 at 12:18 AM Supercilious Dude <supercilious.d...@gmail.com> wrote: > > It would be be useful to have the ability to scrub only the metadata. In many > cases the data is so large that a full scrub is not feasible. In my "little" > test system of 34TB a full scrub takes many hours and the IOPS saturate the > disks to the extent that the volume is unusable due to the high latencies. > Ideally there should be a way to rate limit the scrub operation so that it > can happen in the background without impacting the normal workload.
In effect a 'btrfs check' is a read only scrub of metadata, as all metadata is needed to be read for that. Of course it's more expensive than just confirm checksums are OK, because it's also doing a bunch of sanity and logical tests that take much longer. -- Chris Murphy