Keep in mind that the mds server is cpu-bound, so during heavy workloads it will eat up CPU usage, so the OSD daemons can affect or be affected by the MDS daemon. But it does work well. We've been running a few clusters with MON, MDS and OSDs sharing the same hosts for a couple of years now.
Regards, Webert Lima DevOps Engineer at MAV Tecnologia *Belo Horizonte - Brasil* *IRC NICK - WebertRLZ* On Tue, Jun 19, 2018 at 11:03 AM Paul Emmerich <paul.emmer...@croit.io> wrote: > Just co-locate them with your OSDs. You can can control how much RAM the > MDSs use with the "mds cache memory limit" option. (default 1 GB) > Note that the cache should be large enough RAM to keep the active working > set in the mds cache but 1 million files is not really a lot. > As a rule of thumb: ~1GB of MDS cache per ~100k files. > > 64GB of RAM for 12 OSDs and an MDS is enough in most cases. > > Paul > > 2018-06-19 15:34 GMT+02:00 Denny Fuchs <linuxm...@4lin.net>: > >> Hi, >> >> Am 19.06.2018 15:14, schrieb Stefan Kooman: >> >> Storage doesn't matter for MDS, as they won't use it to store ceph data >>> (but instead use the (meta)data pool to store meta data). >>> I would not colocate the MDS daemons with the OSDS, but instead create a >>> couple of VMs (active / standby) and give them as much RAM as you >>> possibly can. >>> >> >> thanks a lot. I think, we would start with round about 8GB and see, what >> happens. >> >> cu denny >> >> _______________________________________________ >> ceph-users mailing list >> ceph-users@lists.ceph.com >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> > > > > -- > Paul Emmerich > > Looking for help with your Ceph cluster? Contact us at https://croit.io > > croit GmbH > Freseniusstr. 31h > 81247 München > www.croit.io > Tel: +49 89 1896585 90 > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
_______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
