Re: read perf improved by mounting ext2?

From: Kurt Garloff (
Date: Tue Apr 24 2001 - 04:05:32 EST

On Tue, Apr 24, 2001 at 10:58:58AM +0200, Jens Axboe wrote:
> On Tue, Apr 24 2001, Kurt Garloff wrote:
> > There are enough partitions to see a clear pattern: Those with mounted ext2
> > filesystems perform better. Umounting them does not harm, they just need to
> > have been mounted once. reiser or (v)fat however don't improve anything.
> > swap does, as does a ext2 over raid5.
> You wouldn't happen to have 4kB ext2 filesystems on those?

Sure I do.

> When ext2 mounts, it sets the soft blocksize to that then, I would expect
> this to give at least some benefit over using 1kB blocks (as your IDE
> partition otherwise would have).

Why? Are the request sizes larger this way? This would mean that the
overhead is very significant, turning a max of 26MB/s into 16MB/s!

If so, shouldn't we try to get the same effect also for the whole disk or
other filesystems? Most notably reiser?


Kurt Garloff  <>                          Eindhoven, NL
GPG key: See mail header, key servers         Linux kernel development
SuSE GmbH, Nuernberg, FRG                               SCSI, Security

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