On Aug 04, 2009 22:47 +0000, Peter Grandi wrote: > Andreas Dilger wrote: > adilger> Putting 4 OSTs on a single disk doesn't make sense. > adilger> A single OST can be up to 8TB, and if you have multiple > adilger> OSTs on the same disk(s) it will cause terrible > adilger> performance problems due to seeking. > > Uhm, not exactly, that's a quick but simplistic answer: things > are more complicated than that.
[lengthy discussion removed] > Note 3: in many if not most (just a guess) Lustre installations the > "disk" is actually a SAN RAID pool, and each OST is a LUN of that > SAN RAID pool, and that LUN is in effect a slice of a partition off > each disk. Now this is may not be at all what Lustre should be about :-). This is what will happen with any RAID that I'm aware of, and is specifically what I was referring to when I said "disk" instead of "LUN". 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
