should readahead allow generic paths?

[Dave Jones]

On Fri, Oct 12, 2007 at 09:34:05AM +0200, Alexander Larsson wrote:

 > Is there any chance we can use Jens Axboes "fcache"?
 > Info e.g. at:
 > http://en.opensuse.org/Fcache-howto

That really needs to get into the upstream kernel before I'm comfortable
enabling it in Fedora.

 > I don't understand why nobody seems interested in this. It seems like a
 > much nicer solution than readahead of files. In the current version it
 > has to have a separate device for mirroring the blocks, but I can't
 > think its that hard to create a physically linear file on an ext3
 > filesystem

ext3's block allocation policy seems a little.. suboptimal in some cases.
It doesn't seem particularly difficult to end up with fragmented files,
especially with large ones.

 > , lock it in place and use that. (Isn't this basically what
 > extents are?)

ext3 doesn't have extents, and ext4 continues to drag its heals.

	Dave

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