Date: Thu, 28 Sep 2006 15:51:33 -0700 From: Jeremy Chadwick <freebsd@jdc.parodius.com> To: freebsd-stable@freebsd.org Subject: Re: Poor write performance with LSI 320-2 on 6.1-STABLE Message-ID: <20060928225133.GA50669@icarus.home.lan> In-Reply-To: <20060928221505.GA75187@mail1.thewrittenword.com> References: <20060928221505.GA75187@mail1.thewrittenword.com>
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On Thu, Sep 28, 2006 at 05:15:05PM -0500, Albert Chin wrote:
> I don't understand how #1 gives 16MB/s (RAID 1) while #3 gives only
> 17MB/s. I'd expect #3 to be about x2 the performance of #1.
>
> The arrays are configured with "write-thru" write policy, "adaptive"
> read policy, and "cachedio" cache policy.
>
> Anything I can do to improve the speed. Even though the bus is 33Mhz,
> I should definitely be doing better than 16MB/s.
>
> {snip}
>
> I'm running bonnie++ as:
> $ cd [some tmp dir on UFS2 file system]
> $ bonnie++
Pure shot in the dark (I have no experience with LSI controllers,
only Adaptec and Promise): have you tried adjusting some of the
tunefs parameters for the UFS2 filesystem bonnie++ is using?
Options -e and -f may help with this.
Also, at least in the Adaptec world: if the controller does its
own caching (that is, it has actual RAM on-board or DRAM of some
kind), it is sometimes *better* to disable SCSI disk caching on
each individual SCSI drive and let the controller do it. Again,
can't speak for LSI controllers...
--
| Jeremy Chadwick jdc at parodius.com |
| Parodius Networking http://www.parodius.com/ |
| UNIX Systems Administrator Mountain View, CA, USA |
| Making life hard for others since 1977. PGP: 4BD6C0CB |
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