[9189] in linux-scsi channel archive
Re: Benchmarking and correctness
daemon@ATHENA.MIT.EDU (Brian Pomerantz)
Thu Jul 13 15:13:11 2000
Date: Thu, 13 Jul 2000 12:00:29 -0700
From: Brian Pomerantz <bapper@piratehaven.org>
To: Mads Bondo Dydensborg <madsdyd@challenge.dk>
Cc: linux-scsi@vger.rutgers.edu
Message-ID: <20000713120029.A30743@skull.piratehaven.org>
Mail-Followup-To: Mads Bondo Dydensborg <madsdyd@challenge.dk>,
linux-scsi@vger.rutgers.edu
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In-Reply-To: <Pine.LNX.4.21.0007132048391.27120-100000@challenge.dk>
On Thu, Jul 13, 2000 at 08:51:00PM +0200, Mads Bondo Dydensborg wrote:
> On Thu, 13 Jul 2000, Brian Pomerantz wrote:
>
> > On Thu, Jul 13, 2000 at 11:40:20AM +0200, Mads Bondo Dydensborg wrote:
> > > Hi there - a couple of questions I hope you will help me with
> > >
> > > I have made some modifications to a scsi driver, and need to benchmark
> > > it. I know about bonnie, but I was wondering if there where other relevant
> > > benchmarking utilities?
> > >
> > > Is there a way to flush the buffer cache? Right now I reboot to make sure
> > > I read from the disk, but that is kinda annoying.
> > >
> > > Also, are there any "correctness" tests? I have a disk connected to the
> > > SCSI controller and would like to be sure that I handle all the
> > > "neccesary" SCSI commands.
> > >
> >
> > Using a raw device is a good way to get true numbers for your device.
> > Even a 'time dd if=/dev/raw1 of=/dev/null' style test can give pretty
> > good results
>
> I did that, unfortunatly I got this :
>
> [root@sci10 linux-2.2.13]# time dd if=/dev/sdb of=/dev/null bs=1024k
Nope, using that device is not using the raw device. The raw device
requires that you bind a /dev/raw[n] device to a block device, then
you would use dd like so:
time dd if=/dev/raw1 of=/dev/null bs=1024k count=1
I haven't ever used the raw device in the 2.4.x tree but I've been
successfully using the SGI Raw I/O raw device in the 2.2.x tree. The
SGI raw device patch only works with SCSI device and doesn't require
that you bind a raw device to a block device.
BAPper
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