On Sat, Mar 01, 2008 at 03:07:59PM -0500, Bill Davidsen wrote: > Janek Kozicki wrote: > >Janek Kozicki said: (by the date of Thu, 28 Feb 2008 19:25:00 +0100) > > > >sorry about replying to myself. > > > >* two 6 disks raid10 arrays : theoretical max speed 6 times single disc > >* three 4 disks raid10 arrays : theoretical max speed 4 times single disc > >* single raid10 far=2 : theoretical max speed 12 times single disc (!) > > > >isn't that true? > > > > > True for throughput, not for seek. Also, what I have seen and read > indicates that smaller chunks help a lot for database with lots of seeks. Why not for seek? I would have thought that seeks are almost the same, and actually smaller for raid10,n2 with more disks, as raid10,f2 limits read searches to the first part of the disks, and head movement thus are much smaller, say 1/12 of the whole disk in stead of 1/4 for each of the disks in a 4 disk array. Best regards keld -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
