On Tue, Feb 19, 2008 at 01:52:21PM -0600, Jon Nelson wrote: > On Feb 19, 2008 1:41 PM, Oliver Martin > <oliver.martin@xxxxxxxxxxxxxxxxxxxx> wrote: > > Janek Kozicki schrieb: > > > > $ hdparm -t /dev/md0 > > > > /dev/md0: > > Timing buffered disk reads: 148 MB in 3.01 seconds = 49.13 MB/sec > > > > $ hdparm -t /dev/dm-0 > > > > /dev/dm-0: > > Timing buffered disk reads: 116 MB in 3.04 seconds = 38.20 MB/sec > > I'm getting better performance on a LV than on the underlying MD: > > # hdparm -t /dev/md0 > > /dev/md0: > Timing buffered disk reads: 408 MB in 3.01 seconds = 135.63 MB/sec > # hdparm -t /dev/raid/multimedia > > /dev/raid/multimedia: > Timing buffered disk reads: 434 MB in 3.01 seconds = 144.04 MB/sec > # As people are trying to point out in many lists and docs: hdparm is *not* a benchmark tool. So its numbers, while interesting, should not be regarded as a valid comparison. Just my oppinion. regards, iustin - 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