Date: Wed, 14 Jan 2004 15:27:11 +0200 From: Ari Suutari <ari@suutari.iki.fi> To: Karl Pielorz <kpielorz@tdx.co.uk>, freebsd-stable@freebsd.org Subject: Re: Adaptect raid performance with FreeBSD Message-ID: <200401141527.11930.ari@suutari.iki.fi> In-Reply-To: <741002750.1074086443@rainbow> References: <200401141453.50150.ari@suutari.iki.fi> <741002750.1074086443@rainbow>
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Hi,
On Wednesday 14 January 2004 15:20, Karl Pielorz wrote:
> > So, I get only about 25MB/s. Shouldn't I be getting something
> > like 70 MB/s, or even more since there are two disks that
> > can server read requests ?
>
> Hmmm, what happens if you run two of those at once?
Running 5 dd's at once gives in iostat:
tty da0 da1 acd0 cpu
tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id
1 146 0.00 0 0.00 64.00 473 29.58 0.00 0 0.00 0 0 1 1 98
0 38 0.00 0 0.00 64.00 625 39.06 0.00 0 0.00 0 0 2 1 97
0 38 0.00 0 0.00 64.00 492 30.76 0.00 0 0.00 0 0 2 1 97
0 38 0.00 0 0.00 64.00 506 31.62 0.00 0 0.00 0 0 1 0 98
0 38 0.00 0 0.00 64.00 495 30.94 0.00 0 0.00 0 0 1 1 98
The peak seems to be 39 Mb/s.
>
> But, I can't remember seeing adjusting it making any real-world difference
> - what happens if you max it out (e.g. 128, or 256)?
I'll have to try this. However, I also doubt that it is not going
to change anything.
Ari S.
--
Ari Suutari
Lemi, Finland
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