Re: ext2fs enhacement/fix [re: shrinking directories]

Anthony Barbachan (barbacha@trill.cis.fordham.edu)
Sat, 18 Jul 1998 02:36:56 -0400


-----Original Message-----
From: Jan Kara <jack@atrey.karlin.mff.cuni.cz>
To: Anthony Barbachan <barbacha@trill.cis.fordham.edu>
Cc: Ted Deppner <ted@jasmine.psyber.com>; Chad C Giffin <typo@t-net.org>;
linux-kernel@vger.rutgers.edu <linux-kernel@vger.rutgers.edu>
Date: Friday, July 17, 1998 12:02 PM
Subject: Re: ext2fs enhacement/fix [re: shrinking directories]

>> How about a simple utility, added to the ext2 utilities, that compacts
>> directories that can be run periodically as the user wishes. By the way

> This is of course possible but it's very hard (if not almost impossible)
>to do it when filesystem is mounted...

I doubt this, the directory is after all just a special file. The program
could check to time stamp before updating and give it three tries.

>> don't these ghost entries hamper performance, albeit possibly by a
>> negligible amount. I would think that these ghost entries get processed
>> along with the other entries whenever the directory is accessed. And if
>> this utility is made other file system optimization options can be thrown
>> in. Perhaps the directory entries can be sorted by their last access
date
>> as the directory is compacted so as to improve file access performance.
> But keeping the directory sorted will cost you probably more than you
gain.
>And you have completely forgotten the dchache. So the used files will be
>in it and so they won't be looked up on the disk..
>

I said run the utility "periodically", this doesn't mean all the time.
Perhaps once a week along with a fsck.

> Bye Honza.
>

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