Roger Lucas wrote:

quoted

-----Original Message-----
From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-
owner@vger.kernel.org] On Behalf Of Bill Davidsen
Sent: 30 November 2006 14:13
To: linux-raid@vger.kernel.org
Subject: Odd (slow) RAID performance

Pardon if you see this twice, I sent it last night and it never showed
up...

I was seeing some bad disk performance on a new install of Fedora Core
6, so I did some measurements of write speed, and it would appear that
write performance is so slow it can't write my data as fast as it is
generated :-(
    

What drive configuration are you using (SCSI / ATA / SATA), what chipset is
providing the disk interface and what cpu are you running with?

3xSATA, Seagate 320 ST3320620AS, Intel 6600, ICH7 controller using the 
ata-piix driver, with drive cache set to write-back. It's not obvious to 
me why that matters, but if it helps you see the problem I''m glad to 
provide the info. I'm seeing ~50MB/s on the raw drive, and 3x that on 
plain stripes, so I'm assuming that either the RAID-5 code is not 
working well or I haven't set it up optimally.

-- 
bill davidsen [off-list ref]
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979