Thanks for your answer. Le jeudi 29 mars 2018 à 13:51 -0700, Patrick Donnelly a écrit : > On Thu, Mar 29, 2018 at 1:02 PM, Nicolas Huillard <nhuillard@dolomede > .fr> wrote: > > I manage my 2 datacenters with Pacemaker and Booth. One of them is > > the > > publicly-known one, thanks to Booth. > > Whatever the "public datacenter", Ceph is a single storage cluster. > > Since most of the cephfs traffic come from this "public > > datacenter", > > I'd like to suggest or force the active MDS to move to the same > > datacenter, hoping to reduce trafic on the inter-datacenter link, > > and > > reduce cephfs metadata operations latency. > > > > Is it possible for forcefully move the active MDS using external > > triggers ? > > No and it probably wouldn't be beneficial. The MDS still needs to > talk > to the metadata/data pools and increasing the latency between the MDS > and the OSDs will probably do more harm.
It wasn't clear in my first post: OSDs are already split between both DCs, so having the MDS on either side has the same effect on MDS-OSD traffic. It appears that my current usage profile generates load on the MDS, but not that much on OSD-metadata. The public DC is just the one of the two that Booth gives its ticket to. > One possibility for helping your situation is to put NFS-Ganesha in > the public datacenter as a gateway to CephFS. This may help with your > performance by (a) sharing a larger cache among multiple clients and > (b) reducing capability conflicts between clients thereby resulting > in > less metadata traffic with the MDS. Be aware an HA solution doesn't > yet exist for NFS-Ganesha+CephFS outside of Openstack Queens > deployments. I'll keep it stupid-simple then, just use the cephfs client, and monitor the usage profile of things ;-) -- Nicolas Huillard _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
