Hello Stefan, On Thu, Jan 4, 2018 at 1:45 AM, Stefan Kooman <stefan@xxxxxx> wrote: > I have a question about the "mds_cache_memory_limit" parameter and MDS > memory usage. We currently have set mds_cache_memory_limit=150G. > The MDS server itself (and its active-standby) have 256 GB of RAM. > Eventually the MDS process will consume ~ 87.5% of available memory. > At that point it will trim its cache, confirmed with: > > while sleep 1; do ceph daemon mds.mds1 perf dump | jq '.mds_mem.rss'; ceph > daemon mds.mds1 dump_mempools | jq -c '.mds_co'; done > > 1 cephfs kernel client (4.13.0-21-generic), Ceph 12.2.2. > > Anyways, it will consume roughly 1.5 times the amount of memory it is > allowed to use according to mds_cache_memory_limit. Is this expected > behaviour? It's expected but not desired: http://tracker.ceph.com/issues/21402 The memory usage tracking is off by a constant factor. I'd suggest just lowering the limit so it's about where it should be for your system. -- Patrick Donnelly _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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