On Sat May 22, 2004 at 09:13:53 +1000, David Kempe wrote: >Hey anyone have a simple explanation for this phenomenom? >I have 2 * 120Gb SATA drives on an Intel ICH5 controller. >My hdparm scores for both drives are : > >scythe:~# hdparm -t /dev/hdc > >/dev/hdc: > Timing buffered disk reads: 168 MB in 3.02 seconds = 55.55 MB/sec > >scythe:~# hdparm -t /dev/hdd > >/dev/hda: > Timing buffered disk reads: 168 MB in 3.00 seconds = 55.93 MB/sec
Hdparm measures a contiguous 168MB read, I'm guessing that possibly resync on raid is doing random access. (I really don't know how that works, maybe it doesn't do random access, in which case hints from others may be applicable). >I have made two RAID1 mirrors across the drives and the resync is going >considerably slower than that. I realise that the hdparm tests read, but >why so slow on the resync? > >like so: >5.5% (3269632/58593408) finish=451.5min speed=2041K/sec This number seems reasonable if you are doing a lot of seeks. Benno -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
