Message-ID: <493C3570.4040100@redhat.com>
Date: Sun, 07 Dec 2008 14:43:28 -0600
From: Eric Sandeen <sandeen@redhat.com>
User-Agent: Thunderbird 2.0.0.18 (Macintosh/20081105)
MIME-Version: 1.0
To: Theodore Tso <tytso@mit.edu>, Eric Sandeen <sandeen@redhat.com>,
       Christoph Hellwig <hch@infradead.org>,
       Harald Arnesen <skogtun.harald@gmail.com>, linux-kernel@vger.kernel.org,
       linux-ext4@vger.kernel.org
Subject: Re: [ext4] Documentation patch
References: <8763m3u9kv.fsf@basilikum.skogtun.org> <20081201165700.GA26680@infradead.org> <493425DC.1010008@redhat.com> <20081201205828.GA20069@mit.edu> <20081206222534.GJ1323@mit.edu> <493B0BAD.10004@redhat.com> <20081207183916.GB15998@mit.edu>
In-Reply-To: <20081207183916.GB15998@mit.edu>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1669
Lines: 37

Theodore Tso wrote:
> Good points.  OK, how about this?
>      	      
>   - When comparing performance with other filesystems, it's always
>     important to try multiple workloads; very often a subtle change in a
>     workload parameter can completely change the ranking of which
>     filesystems do well compared to others.  When comparing versus ext3,
>     note that ext4 enables write barriers by default, while ext3 does
>     not enable write barriers by default.  So it is useful to use
>     explicitly specify whether barriers are enabled or not when via the
>     '-o barriers=[0|1]' mount option for both ext3 and ext4 filesystems
>     for a fair comparison.  When tuning ext3 for best benchmark numbers,
>     it is often worthwhile to try changing the data journaling mode; '-o
>     data=writeback,nobh' can be faster for some workloads.  (Note
>     however that running mounting with data=writeback can potentially

I'd say "running mounted with data=writeback...."

other than that it looks good to me :)

(sorta nitpicky but it probably won't be touched again for 5 years so
may as well get it right now) :)

-Eric

>     leave stale data exposed in recently written files in case of an
>     unclean shutdown, which could be a security exposure in some
>     situations.)  Configuring the filesystem with a large journal can
>     also be helpful for metadata-intensive workloads.
> 
> 							- Ted

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/