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Re: is thee anyway to pre-alloc space for a dir that is going to get a b

To: Dave Chinner <david@xxxxxxxxxxxxx>
Subject: Re: is thee anyway to pre-alloc space for a dir that is going to get a bunch of long filenames? (+ frag scripts)
From: Linda Walsh <xfs@xxxxxxxxx>
Date: Thu, 17 Jan 2013 19:53:35 -0800
Cc: xfs-oss <xfs@xxxxxxxxxxx>
Delivered-to: xfs@xxxxxxxxxxx
In-reply-to: <20130116121045.GE2498@dastard>
References: <50F642C6.8050705@xxxxxxxxx> <20130116121045.GE2498@dastard>
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Dave Chinner wrote:
On Tue, Jan 15, 2013 at 10:03:50PM -0800, Linda Walsh wrote:
Was doing some createrepo ops with about 3k rpms and it created a
cachedir w/~10k LONG entries .. size of the dir was(is) 348k,
did a frag count on it and it had 155 fragments.  Ouch.

Anyway to pre-alloc a dir or some means get a dir w/fewer frags...

No.

Mostly curiosity -- though I'd fix it if there was an easy fix -- but
it's not a dir that's going to get much access, so it doesn't matter
alot.

Just because the directory has lots of extents, it doesn't
mean it is fragmented. Indeed, the directory read order may be a
different order to the order of extents, especially as tehre are
multiple trees/indexes in the directory structure that are used
depending on the type of access. So unless you have a performance
problem, there is nothing to "fix". And if you do have a perf
problem with large directories, then use a larger directory block
size....
----
Thanks!...it's not a problem, just my anal retentiveness! ;-)


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