On Tue, Jul 11, 2017 at 3:44 AM, David Turner <drakonstein@xxxxxxxxx> wrote: > Mons are a paxos quorum and as such want to be in odd numbers. 5 is > generally what people go with. I think I've heard of a few people use 7 > mons, but you do not want to have an even number of mons or an ever growing Unless your cluster is very large three should be sufficient. > number of mons. The reason you do not want mons running on the same > hardware as osds is resource contention during recovery. As long as the Xen > servers you are putting the mons on are not going to cause any source of > resource limitation/contention, then virtualizing them should be fine for > you. Make sure that you aren't configuring the mon to run using an RBD for > its storage, that would be very bad. > > The mon Quorum elects a leader and that leader will be in charge of the > quorum. Having local mons doesn't do anything as the clients will still be > talking to the mons as a quorum and won't necessarily talk to the mon > running on them. The vast majority of communication to the cluster that > your Xen servers will be doing is to the OSDs anyway, very little > communication to the mons. > > On Mon, Jul 10, 2017 at 1:21 PM Massimiliano Cuttini <max@xxxxxxxxxxxxx> > wrote: >> >> Hi everybody, >> >> i would like to separate MON from OSD as reccomended. >> In order to do so without new hardware I'm planning to create all the >> monitor as a Virtual Machine on top of my hypervisors (Xen). >> I'm testing a pool of 8 nodes of Xen. >> >> I'm thinking about create 8 monitor and pin one monitor for one Xen node. >> So, i'm guessing, every Ceph monitor'll be local for each node client. >> This should speed up the system by local connecting monitors with a >> little overflown for the monitors sync between nodes. >> >> Is it a good idea have a local monitor virtualized on top of each >> hypervisor node? >> Did you see any understimation or wrong design in this? >> >> Thanks for every helpfull info. >> >> >> Regards, >> Max >> >> _______________________________________________ >> ceph-users mailing list >> ceph-users@xxxxxxxxxxxxxx >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- Cheers, Brad _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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