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From: Jens Axboe <axboe@suse.de>
To: Holger Kiehl <Holger.Kiehl@dwd.de>
Cc: Vojtech Pavlik <vojtech@suse.cz>,
	linux-raid <linux-raid@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Where is the performance bottleneck?
Date: Wed, 31 Aug 2005 19:35:26 +0200	[thread overview]
Message-ID: <20050831173525.GJ4018@suse.de> (raw)
In-Reply-To: <Pine.LNX.4.61.0508311648390.16574@diagnostix.dwd.de>

On Wed, Aug 31 2005, Holger Kiehl wrote:
> ># ./oread /dev/sdX
> >
> >and it will read 128k chunks direct from that device. Run on the same
> >drives as above, reply with the vmstat info again.
> >
> Using kernel 2.6.12.5 again, here the results:

[snip]

Ok, reads as expected, like the buffered io but using less system time.
And you are still 1/3 off the target data rate, hmmm...

With the reads, how does the aggregate bandwidth look when you add
'clients'? Same as with writes, gradually decreasing per-device
throughput?

-- 
Jens Axboe


  reply	other threads:[~2005-08-31 17:35 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-08-29 18:20 Where is the performance bottleneck? Holger Kiehl
2005-08-29 19:54 ` Mark Hahn
2005-08-30 19:08   ` Holger Kiehl
2005-08-30 23:05     ` Guy
2005-09-28 20:04       ` Bill Davidsen
2005-09-30  4:52         ` Guy
2005-09-30  5:19           ` dean gaudet
2005-10-06 21:15           ` Bill Davidsen
2005-08-29 20:10 ` Al Boldi
2005-08-30 19:18   ` Holger Kiehl
2005-08-31 10:30     ` Al Boldi
2005-08-29 23:09 ` Peter Chubb
     [not found] ` <20050829202529.GA32214@midnight.suse.cz>
2005-08-30 20:06   ` Holger Kiehl
2005-08-31  7:11     ` Vojtech Pavlik
2005-08-31  7:26       ` Jens Axboe
2005-08-31 11:54         ` Holger Kiehl
2005-08-31 12:07           ` Jens Axboe
2005-08-31 13:55             ` Holger Kiehl
2005-08-31 14:24               ` Dr. David Alan Gilbert
2005-08-31 20:56                 ` Holger Kiehl
2005-08-31 21:16                   ` Dr. David Alan Gilbert
2005-08-31 16:20               ` Jens Axboe
2005-08-31 15:16                 ` jmerkey
2005-08-31 16:58                   ` Tom Callahan
2005-08-31 15:47                     ` jmerkey
2005-08-31 17:11                   ` Jens Axboe
2005-08-31 15:59                     ` jmerkey
2005-08-31 17:32                       ` Jens Axboe
2005-08-31 16:51                 ` Holger Kiehl
2005-08-31 17:35                   ` Jens Axboe [this message]
2005-08-31 19:00                     ` Holger Kiehl
2005-08-31 18:06                   ` Michael Tokarev
2005-08-31 18:52                     ` Ming Zhang
2005-08-31 18:57                       ` Ming Zhang
2005-08-31 12:24           ` Nick Piggin
2005-08-31 16:25             ` Holger Kiehl
2005-08-31 17:25               ` Nick Piggin
2005-08-31 21:57                 ` Holger Kiehl
2005-09-01  9:12                   ` Holger Kiehl
2005-09-02 14:28                     ` Al Boldi
2005-08-31 13:38       ` Holger Kiehl

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