Hi, That's interesting -- yes on a lightly loaded cluster the metadata IO should be almost nil. You can debug what is happening using ceph daemonperf on the active MDS, e.g. https://pastebin.com/raw/n0iD8zXY (Use a wide terminal to show all the columns). Normally, lots of md io would indicate that the cache size is too small for the workload; but since you said the clients are pretty idle, this might not be the case for you. Cheers, Dan On Thu, Jul 8, 2021 at 9:36 AM Flemming Frandsen <dren.dk@gmail.com> wrote:
We have a nautilus cluster where any metadata write operation is very slow.
We're seeing very light load from clients, as reported by dumping ops in flight, often it's zero.
We're also seeing about 100 MB/s writes to the metadata pool, constantly, for weeks on end, which seems excessive, as only 22GB is utilized.
Should the writes to the metadata pool not quiet down when there's nothing going on?
Is there any way i can get information about why the MDSes are thrashing so badly? _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io