Re: AWFUL reshape speed with raid5.

On Mon, Jul 28, 2008 at 2:59 PM, David Lethe [off-list ref] wrote:

quoted

-----Original Message-----
From: linux-raid-owner@vger.kernel.org

[mailto:linux-raid-owner@vger.kernel.org] On Behalf Of Justin Piszcz

quoted

Sent: Monday, July 28, 2008 2:44 PM
To: Jon Nelson
Cc: LinuxRaid
Subject: Re: AWFUL reshape speed with raid5.

There once was a bug in an earlier kernel, in which the min_speed is

what

quoted

the rebuild ran at if you had a specific chunk size, have you tried to
echo 30000 > to min_speed?  Does it increase it to 30mb/s for the

rebuild?

As I said in my original post, I'm running 2.6.25.11

You are incorrectly working from the premise that vmstat is measures
disk activity.  It does not.  Vmstat has no idea how many actual bytes
get sent to, or received from disk drives.

Fair enough.

Why not do a real test and hook up a pair of SAS, SCSI, or FC disks,

...

Cost.

-- 
Jon