[7410] in linux-scsi channel archive
RE: Very slow writes with Hardware SCSI RAID
daemon@ATHENA.MIT.EDU (Matthew Clark)
Fri Oct 22 22:32:29 1999
Reply-To: <matt@genicomsystems.co.uk>
From: "Matthew Clark" <matt@genicomsystems.co.uk>
To: "linux-scsi" <linux-scsi@vger.rutgers.edu>,
"linux-raid" <linux-raid@vger.rutgers.edu>
Date: Sat, 23 Oct 1999 03:26:00 +0100
Message-ID: <007701bf1cfd$f1fd34b0$0100a8c0@netdespatch.co.uk>
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By the way, I'm using Linux Kernel 2.2.10 SMP
Matthew.
> -----Original Message-----
> From: owner-linux-scsi@vger.rutgers.edu
> [mailto:owner-linux-scsi@vger.rutgers.edu]On Behalf Of Matthew Clark
> Sent: 22 October 1999 14:11
> To: linux-scsi; linux-raid
> Subject: Very slow writes with Hardware SCSI RAID
>
>
> Hi there,
>
> I post this to both mailing lists as I am unsure exactly where my problem
> lies.
>
> I have a PIII 500 HP Netserver LH4 with 256Mb RAM
> SYM38c95 on-board SCSI controller with
> HP NetRaid (MegaRaid Rebadge) on channel A
> Adaptec 2940 U2W (AIC-7890AB) with
> HP DLT SCSI 40Gb Tape drive
> Latest aic7xxx & Megaraid drivers
>
> If I run bonnie with 300Meg size, I get very low performance readings.
>
> bonnie -s 300
> -------Sequential Output-------- ---Sequential
> Input-- --Random--
> -Per Char- --Block--- -Rewrite-- -Per
> Char- --Block--- --Seeks---
> Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
> %CPU
> 1* 300 441 6.8 437 1.7 2439 5.2 5657 70.7 26561 27.1 787.2
> 9.4
>
> I can't figure out where the bottleneck is.. I did notice today
> however that
> the SYMBIOS driver does not appear in the DMesg output - is it possible to
> talk to the Megaraid card without loading the Symbios drivers?If
> yes, would
> this slow the drives down?
>
> When the drive is first formatted, with no data (apart from lost+found) I
> get nearer 8000K/sec on Per Char output...
>
> Regards,
>
> Matthew Clark.
> --
> NetDespatch Ltd - The Internet Call Centre.
> http://www.netdespatch.com
>
>
>
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