On 2009-11-09, at 08:31, Brian J. Murrell wrote: > On Mon, 2009-11-09 at 16:25 +0800, lelustre wrote: >> So my question is :if I want an OST to failover to any OSS (one of >> sixty nodes),should I need to defined 60 failnodes when I format the >> disk? > > I'm not really sure that 60 nodes for every OST is really practical > though. When an OSS does fail, the process of finding the OST on a > failover node is serial and linear. That is, when the OSS providing > an > OST dies, the client cycles through the OST's failover list trying > each > OSS, serially, until it finds the OST. The time given to each > discovery > attempt is not trivial (i.e. a few seconds or less) so hunting through > 60 of them will take considerable time. > >> or can I use pacemaker to select an oss and modify something to >> notify >> client that the disk is on some OSS？ > > No. There is currently no way to push a client towards an OSS for a > given OST.
That is what the "Imperative Recovery" feature is - having the failover server notify the client that it has taken over an OST/MDT filesystem, rather than waiting for the client to time out its RPC and poke around trying to find which of the failover servers is controlling the OST/MDT. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
