On Wed, Nov 20, 2024 at 2:05 PM Rajmohan Ramamoorthy <ram.rajmohanr@xxxxxxxxx> wrote: > > Hi Patrick, > > Few other follow up questions. > > Is directory fragmentation applicable only when multiple active MDS is enabled for a Ceph FS? It has no effect when applied with only one rank (active). It can be useful to have it already set in case you increase max_mds. > Will directory fragmenation and distribution of fragments amongs active MDS happen if we turn off balancer for a Ceph FS volume `ceph fs set midline-a balance_automate false` ? In Squide, the CephFS automatic metadata load (sometimes called “default”) balancer is now disabled by default. (https://docs.ceph.com/en/latest/releases/squid/) Yes. > Is there a way for us to ensure that the directory tree of a Subvolume (Kubernetes PV) is part of a same fragment and handled by a single MDS so that a client operations are handled by one MDS? A subvolume would not be split across two MDS. > What is the trigger to start fragmenting directories within a Subvolumegroup? You don't need to do anything more than set the distribute ephemeral pin. > With the `balance_automate` set to false and `ephemeral distributed pin` enabled for a Subvolumegroup, can we expect (almost) equal distribution of Subvolumes (Kubernetes PVs) amongst the active MDS daemons and stable operation without hotspot migrations? Yes. -- Patrick Donnelly, Ph.D. He / Him / His Red Hat Partner Engineer IBM, Inc. GPG: 19F28A586F808C2402351B93C3301A3E258DD79D _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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