I would not do this, MONs are very important and any load or stability issues on OSD nodes would interfere with the cluster uptime. I found it acceptable to run MONs on virtual machines with local storage. But since MONs oversee OSD nodes, I believe combining them is a recipe for disaster, FWIW. Regards, Alex On Thu, Jun 25, 2015 at 12:37 PM, Shane Gibson <Shane_Gibson@xxxxxxxxxxxx> wrote: > > For a small deployment this might be ok - but as mentioned, mon logging > might be an issue. Consider the following: > > * disk resources for mon logging (maybe dedicate a disk to logging, to > avoid disk IO contention for OSDs) > * CPU resources, some Filesystem types for OSDs can eat a lot of CPU > (that' good, they're doing hard work, your using those resources to gain > performance!!) > * consider memory pressure of both mons and OSDs - Filesystem cache in > memory is a good thing, are you going to be impacting that w/ comingling > mons? > > If you have fairly decent machines with more cores/HTs than OSD disks, you > probably don't have a huge CPU issue to worry about (...probably...). > > ~~shane > > On 6/25/15, 9:23 AM, "ceph-users on behalf of Quentin Hartman" > <ceph-users-bounces@xxxxxxxxxxxxxx on behalf of > qhartman@xxxxxxxxxxxxxxxxxxx> wrote: > > The biggest downside that I've found is the log volume that mons create eats > a lot of io. I was running mons on my OSDs previously, but in my current > dpeloyment I've moved them to other hardware and noticed a perceptible load > reduction on those nodes that were formerly running mons. > > QH > > On Thu, Jun 25, 2015 at 10:21 AM, Lazuardi Nasution <mrxlazuardin@xxxxxxxxx> > wrote: >> >> Hi, >> >> I'm looking for pros and cons of combining MON and OSD functionality on >> the same nodes. Mostly recommended configuration is to have dedicated, odd >> number MON nodes. What I'm thinking is more like single node deployment but >> consist more than one node, if we have 3 nodes we have 3 MONs with 3 OSDs. >> Since MON will only consume small resources, I think MON load will not >> degrade OSD performance significantly. If we have odd number of nodes, we >> can still maintain the quorum of MON with this way. Any idea? >> >> Best regards, >> >> >> _______________________________________________ >> 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 > _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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