Messages in this thread | | | Date | Sat, 10 Sep 2005 03:53:47 +0100 | From | Nuno Silva <> | Subject | Re: RAID resync speed |
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Hi,
Eyal Lebedinsky wrote: > I noticed that my 3-disk RAID was syncing at about 40MB/s, now that I > added a fourth disk it goes at only 20+MB/s. This is on an idle machine.
3*40=120
4*20=80
> Individually, each disk measures 60+MB/s with hdparm.
And concurrent hdparms? Or some dd's concurrently?
> kernel: 2.6.13 on ia32 > Controller: Promise SATAII150 TX4 > Disks: WD 320GB SATA > > Q: Is this the way the raid code works? The way the disk-io is managed? Or > could it be due to the SATA controller?
You can isolate the performance drop with some dd's. Maybe this card is in a pci32/33mhz and you're hitting the pci bus' limits? (120~130MB/sec).
Regards, Nuno Silva
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