Hello Mark, for multi-mds solutions do you refer to multi-active arch or 1 active and many standby arch? http://ceph.com/docs/master/architecture/ says: ----- The Ceph filesystem service is provided by a daemon called ceph-mds. It uses RADOS to store all the filesystem metadata (directories, file ownership, access modes, etc), and directs clients to access RADOS directly for the file contents. The Ceph filesystem aims for POSIX compatibility. ceph-mds can run as a single process, or it can be distributed out to multiple physical machines, either for high availability or for scalability. High Availability: The extra ceph-mds instances can be standby, ready to take over the duties of any failed ceph-mds that was active. This is easy because all the data, including the journal, is stored on RADOS. The transition is triggered automatically by ceph-mon. Scalability: Multiple ceph-mds instances can be active, and they will split the directory tree into subtrees (and shards of a single busy directory), effectively balancing the load amongst all active servers. Combinations of standby and active etc are possible, for example running 3 active ceph-mds instances for scaling, and one standby intance for high availability. ----- I saw cases while standby mds took over traffic from the active one. Looks like it's working. Would you please clarify. I tried to disable 2 standby mds and happily reproduced the problem ) so, it's something else. I will try playing with mds log level and provide more accurate details. thanks! 2012/12/19 Mark Nelson <mark.nelson@xxxxxxxxxxx>: > > > A quicky side-node: multi-mds solutions aren't being supported in > production right now. Not sure if your stat problems below are related, but > you may want to try starting out with a single mds and see if the problem > goes away. If so, there may be some hints in the mds logs regarding what's > going on. Bug reports are welcome! > >> >> [osd.0] >> host = ceph-node01 >> >> [osd.1] >> host = ceph-node02 >> >> [osd.2] >> host = ceph-node03 -- ...WBR, Roman Hlynovskiy -- 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
