On Wed, Apr 17, 2013 at 7:40 AM, Guido Winkelmann <guido@xxxxxxxxxxxxxxxxx> wrote: > Hi, > > I just tried upgrading parts of our experimental ceph cluster from 0.56.1 to > 0.60, and it looks like the new mon-daemon from 0.60 cannot talk to those from > 0.56.1 at all. > > Long story short, we had to move some hardware around and during that time I > had to shrink the cluster to one single machine. My plan was to expand it to > three machines again, so that I would again have 3 mons and 3 osds, as before. > I just installed the first new machine, going straight for 0.60, but leaving > the remaining old one at 0.56.1. I added the new mon to the mon map according > to the documentation and started the new mon daemon, but the mon-cluster > wouldn't achieve quorum. In the logs for the new mon, I saw the following line > repeated a lot: > > 0 -- 10.6.224.129:6789/0 >> 10.6.224.131:6789/0 pipe(0x2da5ec0 sd=20 :37863 > s=1 pgs=0 cs=0 l=0).connect protocol version mismatch, my 10 != 9 > > The old mon had no such lines in its log. > > I could only solve this by shutting down the old mon and upgrading it to 0.60 > as well. > > It looks to me like this means rolling upgrades without downtime won't be > possible from bobtail to cuttlefish. Is that correct? If the cluster is in good shape, this shouldn't actually result in downtime. Do a rolling upgrade of your monitors, and then when a majority of them are on Cuttlefish they'll switch over to form the quorum — the "downtime" being the period a store requires to update, which shouldn't be long, and it will only be the monitors that are inaccessible (unless it takes a truly ridiculous time for the upgrade). All the rest of the daemons you can do rolling upgrades on just the same as before. -Greg Software Engineer #42 @ http://inktank.com | http://ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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