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From: Eric Sandeen <sandeen@redhat.com>
To: Justin Piszcz <jpiszcz@lucidpixels.com>
Cc: 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 18:08:24 -0600	[thread overview]
Message-ID: <4B8C56F8.70503@redhat.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1002261922010.8247@p34.internal.lan>

Justin Piszcz wrote:
> Hello,
> 
> Is it possible to 'optimize' ext4 so it is as fast as XFS for writes?
> I see about half the performance as XFS for sequential writes.
> 
> I have checked the doc and tried several options, a few of which are shown
> below (I have also tried the commit/journal_async/etc options but none
> of them get the write speeds anywhere near XFS)?
> 
> Sure 'dd' is not a real benchmark, etc, etc, but with 10Gbps between 2
> hosts I get 550MiB/s+ on reads from EXT4 but only 100-200MiB/s write.
> 
> When it was XFS I used to get 400-600MiB/s for writes for the same RAID
> volume.
> 
> How do I 'speed' up ext4?  Is it possible?
> 

FWIW I'm seeing similar things on fast storage (Fusion IO),
though this is under 2.6.31.  500MB/s+ for xfs, 300 for ext4.

Overwriting an existing file is no faster.   I don't think this
driver is blktraceable but I'll try a newer driver that should be I think.

(xfs's overwrite went from 534 to 597 mb/s; ext4 sat at 320-ish)

direct IO was good for both xfs & ext4 at around 530mb/s

I'll see if I can get this running on a more recent kernel to
do further investigation.

-Eric

  parent reply	other threads:[~2010-03-02  0:08 UTC|newest]

Thread overview: 21+ 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
2010-02-27  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
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 [this message]
2010-03-02  0:37   ` Eric Sandeen

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