From mboxrd@z Thu Jan  1 00:00:00 1970
From: Henrik Holst <henrik_holst@home.se>
Subject: Re: Raid 1 install revealed poor HD performance (I think)
Date: Wed, 18 May 2005 01:42:05 +0200
Message-ID: <428A814D.3000803@home.se>
References: <428A09A3.9000802@heyjay.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Return-path: <linux-raid-owner@vger.kernel.org>
In-Reply-To: <428A09A3.9000802@heyjay.com>
Sender: linux-raid-owner@vger.kernel.org
To: Jay Strauss <me@heyjay.com>
Cc: linux-raid@vger.kernel.org
List-Id: linux-raid.ids

You might also want to try and force UltraDMA mode5 (or the highest 
UltraDMA mode supported by your hardware) with "hdparm -X69 /dev/hda" 
combined with the "Multiple sector mode" (set with "hdparm -m 16 
/dev/hda") that was suggested earlier.

/ Henrik Holst

Jay Strauss wrote:
> Hi,
> 
> I just installed a simple raid-1.  I have a single HD on each 
> controller.  ie. 2 controllers 2 HDs. That's it, no CD players or DVD 
> drives...
> 
> I did a fresh install of Sarge.  After reboot I unplugged the CD drive, 
> and let the array sync overnight.  It took 10hrs to sync 160GiB, which 
> seemed pretty long, so I executed the "dd if=/dev/hda of=/dev/null 
> bs=64k count=10000" command I've seen posted on this list.
> 
> It took about a minute and change to complete, which is long.  So out of 
> curiosity I plugged in a CD player and booted Knoppix.  When I ran the 
> same command it took only 30 seconds (which is still not as quick as 
> some of the numbers on this list, but it's an old celeron 466MHz).
> 
> I'm very unfamiliar with options for speeding up hard drive access. What 
> might Knoppix be setting (and how would I look for it), that it's 
> getting 100% better drive performance than a plain jane Sarge install?
> 
> Thanks
> Jay
> 
> ******** Knoppix Run ***********
> 
> root@ttyp0[~]# for i in 1 2 3; do
>  > time dd if=/dev/hda of=/dev/null bs=64k count=10000
>  > done
> 10000+0 records in
> 10000+0 records out
> 655360000 bytes transferred in 46.301872 seconds (14154071 bytes/sec)
> 
> real    0m46.754s
> user    0m0.480s
> sys     0m29.710s
> 
> 10000+0 records in
> 10000+0 records out
> 655360000 bytes transferred in 49.852186 seconds (13146063 bytes/sec)
> 
> real    0m51.075s
> user    0m0.430s
> sys     0m26.610s
> 
> 10000+0 records in
> 10000+0 records out
> 655360000 bytes transferred in 46.237684 seconds (14173720 bytes/sec)
> 
> real    0m47.928s
> user    0m0.480s
> sys     0m31.770s
> 
> ************** Sarge Run *************
> 
> sandy:~# for i in 1 2 3; do
>  > time dd if=/dev/hda of=/dev/null bs=64k count=10000
>  > done
> 10000+0 records in
> 10000+0 records out
> 655360000 bytes transferred in 66.004525 seconds (9929016 bytes/sec)
> 
> real    1m6.052s
> user    0m0.637s
> sys     1m2.888s
> 
> 10000+0 records in
> 10000+0 records out
> 655360000 bytes transferred in 63.797226 seconds (10272547 bytes/sec)
> 
> real    1m3.886s
> user    0m0.678s
> sys     1m0.732s
> 
> 10000+0 records in
> 10000+0 records out
> 655360000 bytes transferred in 64.729628 seconds (10124575 bytes/sec)
> 
> real    1m4.822s
> user    0m0.616s
> sys     1m1.668s
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>