On Wed, 15 May 2013, Matt Chipman wrote: > > Hi, > You mention early that one mon is spare but later say that you have 4 mons > running. Ceph explicitly requires an odd number of monitors so a quorum can > be established. Quick correction: you can run any number of monitors, but even numbers are not recommended because there is little benefit in availability. 3 mons means a majority of 2 can form quorum (tolerate 1 failure), while 4 mons requires 3 up (still tolerating only 1 failure). At the margin you are usually better off rounding down to an odd number. But even-sized clusters will still work. sage > > I think you should have 3 or 5 mons running not 3 and a spare. > > Good luck > > On 14/05/2013 12:58 PM, "Mr. NPP" <mr.npp@xxxxxxxxxxxxxxxxxxx> wrote: > hello, i'm currently running 0.61, with about 44 osd's and 4 > monitors, one as a spare. > with about 6 hosts. > > I've been running into an issue where when one ceph host would go down > the entire system become unusable. today we recovered from a ssd crash > crash for an osd's journal, and it was a lot of work to get it back > up, i couldn't get monitors to come up and establish quorum. I was > going to rebuild it manually, but the documentation for ceph is > outdated to manually (dirty) remove a monitor using the monmap tool, i > couldn't find the /mon-$id/monmap directory. > > anyway, I recovered eventually and was able to run with 4 monitors, > and i updated the crushmap and it crashed the monitor that i was > updating the crushmap too. > > it now gives me > > [976]: (33) Numerical argument out of domain > > when i try to manually start it, i've seen this assert failure before, > just not sure whats causing it. > > below i the log from the crash. > https://docs.google.com/a/nopatentpending.com/file/d/0BwQnRodV8ActNTVFUVpLV > jdMSGc/edit > > i'm not even really sure if my configs are right, i'm still pretty new > at this. > > below are the configs, and the last map > > ceph.conf > https://docs.google.com/file/d/0BwQnRodV8Acta3ZfSnBrOU40MW8/edit?usp=sharin > g > > crush.map.txt > https://docs.google.com/file/d/0BwQnRodV8Actbl9hY054Mm9UTXM/edit?usp=sharin > g > > if you need additional dumps from the monitor i can get it. > > thanks > mr.npp > > _______________________________________________ > 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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