From: John Richard Moser <nigelenki@comcast.net>
To: Diego Calleja <diegocg@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>, linux-kernel@vger.kernel.org
Subject: Re: soft update vs journaling?
Date: Sun, 22 Jan 2006 20:00:18 -0500 [thread overview]
Message-ID: <43D42AA2.6040106@comcast.net> (raw)
In-Reply-To: <20060122205039.e8842bae.diegocg@gmail.com>
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Diego Calleja wrote:
> El Sun, 22 Jan 2006 04:31:44 -0500,
> Theodore Ts'o <tytso@mit.edu> escribió:
>
>
>
>>One major downside with Soft Updates that you haven't mentioned in
>>your note, is that the amount of complexity it adds to the filesystem
>>is tremendous; the filesystem has to keep track of a very complex
>>state machinery, with knowledge of about the ordering constraints of
>>each change to the filesystem and how to "back out" parts of the
>>change when that becomes necessary.
>
>
>
> And FreeBSD is implementing journaling for UFS and getting rid of
> softupdates [1]. While this not proves that softupdates is "a bad idea",
> i think this proves why the added sofupdates complexity doesn't seem
> to pay off in the real world.
>
Yeah, the huge TB fsck thing became a problem. I wonder still if it'd
be useful for small vfat file systems (floppies, usb drives); nobody has
led me to believe it's definitely feasible to not corrupt meta-data in
this way.
I guess journaling is looking a lot better. :)
> [1]: http://lists.freebsd.org/pipermail/freebsd-hackers/2004-December/009261.html
>
> "4. Journaled filesystem. While we can debate the merits of speed and
> data integrety of journalling vs. softupdates, the simple fact remains
> that softupdates still requires a fsck run on recovery, and the
> multi-terabyte filesystems that are possible these days make fsck a very
> long and unpleasant experience, even with bg-fsck. There was work at
> some point at RPI to add journaling to UFS, but there hasn't been much
> status on that in a long time. There have also been proposals and
> works-in-progress to port JFS, ReiserFS, and XFS. Some of these efforts
> are still alive, but they need to be seen through to completion"
>
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next prev parent reply other threads:[~2006-01-23 1:01 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-22 6:42 soft update vs journaling? John Richard Moser
2006-01-22 8:51 ` Jan Engelhardt
2006-01-22 18:40 ` John Richard Moser
2006-01-22 19:05 ` Adrian Bunk
2006-01-22 19:08 ` Arjan van de Ven
2006-01-22 19:25 ` Adrian Bunk
2006-01-24 2:33 ` Jörn Engel
2006-01-22 9:31 ` Theodore Ts'o
2006-01-22 18:54 ` John Richard Moser
2006-01-22 21:02 ` Theodore Ts'o
2006-01-22 22:44 ` Kyle Moffett
2006-01-23 7:24 ` Theodore Ts'o
2006-01-23 13:31 ` Mitchell Blank Jr
2006-01-23 13:33 ` Kyle Moffett
2006-01-23 13:52 ` Antonio Vargas
2006-01-23 16:48 ` Linux VFS architecture questions Kyle Moffett
2006-01-23 17:00 ` Pekka Enberg
2006-01-23 17:50 ` Kyle Moffett
2006-01-23 17:54 ` Randy.Dunlap
2006-01-23 20:48 ` soft update vs journaling? Folkert van Heusden
2006-01-23 1:02 ` John Richard Moser
2006-01-22 19:50 ` Diego Calleja
2006-01-22 20:39 ` Suleiman Souhlal
2006-01-22 20:50 ` Diego Calleja
2006-01-23 1:00 ` John Richard Moser [this message]
2006-01-23 1:09 ` Suleiman Souhlal
2006-01-23 2:09 ` John Richard Moser
2006-01-22 19:26 ` James Courtier-Dutton
2006-01-23 0:06 ` John Richard Moser
2006-01-23 5:32 ` Michael Loftis
2006-01-23 18:52 ` John Richard Moser
2006-01-23 19:32 ` Matthias Andree
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