On Mon, 12 Jul 2010, Brian Jackson wrote: > On Monday, July 12, 2010 01:59:38 pm Roland Rabben wrote: > > Have there been any work to get CEPH working with two datacenters? > > > We've talked about it on irc in the past. It's not really what ceph was > designed for, but given sufficient bandwidth between the DCs it should work. > > In your particular situation if 1 DC was disconnected but not down, you could > have an issue if things changed in both locations. You would also have an > issue if connectivity was lost because ceph would try to replicate things up > to 3x at both sites. Well, sort of. If have a network partition, only one partition will be available (whichever can reach the majority of the monitors). No updates will be applied to the disconnected DC. Ceph favors consistency over availability in the presence of a partition. This lends itself to a primary + data backup DC type of situation where the majority (or all) monitors are in the primary DC, but there is no failover. Actual failover would need a one or more monitors is at a third location. But this is not a case that is designed or optimized for, so improvements could definitely be made. sage > > > > > I would like to have two copies of a file at site 1 and a third copy > > at site two. > > > That should be achievable. > > > > And would you be able to continue running with one of the sites down? > > > Well, taking into consideration the things I already mentioned, you should > continue to have access to the filesystem. > > > > > > Best regards > > > > Roland Rabben > > -- > > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
