Re: [ext4] Documentation patch

From: Eric Sandeen
Date: Sun Dec 07 2008 - 15:44:16 EST

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) :)


> 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

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