Jan Engelhardt wrote: > normally, I'd think that combining drives into a raid1 array would give > me at least a little improvement in read speed. In my setup however, > this does not seem to be the case. > > 14:16 opteron:/var/log # hdparm -t /dev/sda > Timing buffered disk reads: 170 MB in 3.01 seconds = 56.52 MB/sec > 14:17 opteron:/var/log # hdparm -t /dev/md3 > Timing buffered disk reads: 170 MB in 3.01 seconds = 56.45 MB/sec > (and dd_rescue shows the same numbers) The problem is that raid1 one doesn't do striped reads, but rather uses read-balancing per proc. Try your test with parallel reads; it should be faster. You could use raid10, but then you loose single-disk-image compatibility. Thanks! -- Al - 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
