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From: Michael Tokarev <mjt@tls.msk.ru>
To: Justin Piszcz <jpiszcz@lucidpixels.com>
Cc: Andreas Dilger <adilger@sun.com>,
	tytso@mit.edu, Eric Sandeen <sandeen@redhat.com>,
	linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
	Alan Piszcz <ap@solarrain.com>
Subject: Re: EXT4 is ~2X as slow as XFS (593MB/s vs 304MB/s) for writes?
Date: Mon, 01 Mar 2010 17:48:16 +0300	[thread overview]
Message-ID: <4B8BD3B0.3020502@msgid.tls.msk.ru> (raw)
In-Reply-To: <alpine.DEB.2.00.1003010419090.20072@p34.internal.lan>

Justin Piszcz wrote:
> 
> On Mon, 1 Mar 2010, Andreas Dilger wrote:
> 
>> On 2010-02-28, at 07:55, Justin Piszcz wrote:
>>> === CREATE RAID-0 WITH 11 DISKS
>>
>> Have you tried testing with "nice" numbers of disks in your RAID set
>> (e.g. 8 disks for RAID-0, 9 for RAID-5, 10 for RAID-6)?  The mballoc
>> code is really much better tuned for power-of-two sized allocations.
> 
> Hi,
> 
> Yes, the second system (RAID-5) has 8 disks and it shows the same
> performance problems with ext4 and not XFS (as shown from previous
> e-mail), where XFS usually got 500-600MiB/s for writes.
> 
> http://groups.google.com/group/linux.kernel/browse_thread/thread/e7b189bcaa2c1cb4/ad6c2a54b678cf5f?show_docid=ad6c2a54b678cf5f&pli=1
> 
> 
> For the RAID-5 (from earlier testing):  <- This one has 8 disks.

Note that for RAID-5, the "nice" number of disks is 9 as Andreas
said, not 8 as in your example.

/mjt

  reply	other threads:[~2010-03-01 14:48 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-27  0:31 EXT4 is ~2X as slow as XFS (593MB/s vs 304MB/s) for writes? Justin Piszcz
2010-02-27  0:46 ` Dmitry Monakhov
2010-02-27  1:05   ` Justin Piszcz
2010-02-28  0:56     ` Asdo
2010-02-28  9:59       ` Justin Piszcz
2010-02-27  0:51 ` Eric Sandeen
2010-02-27  1:08   ` Justin Piszcz
2010-02-27  1:12     ` Eric Sandeen
2010-02-27  1:28       ` Eric Sandeen
2010-02-27 10:14         ` Justin Piszcz
2010-02-27 10:51           ` Justin Piszcz
2010-02-27 11:09             ` Justin Piszcz
2010-02-27 11:36               ` Justin Piszcz
2010-02-28  5:42                 ` tytso
2010-02-28 14:55                   ` Justin Piszcz
2010-03-01  8:39                     ` Andreas Dilger
2010-03-01  9:21                       ` Justin Piszcz
2010-03-01 14:48                         ` Michael Tokarev [this message]
2010-03-01 15:07                           ` Justin Piszcz
2010-03-01 16:15                     ` Eric Sandeen
2010-02-28 23:50                 ` Dave Chinner
2010-03-02  0:08 ` Eric Sandeen
2010-03-02  0:37   ` Eric Sandeen

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