OT - Journaling File Systems?

[Alan Cox]

On Tue, Apr 27, 2004 at 12:03:35PM -0500, Edwards, Scott (MED, Kelly IT Resouces) wrote:
> After the second 'plug pull' it took 1 minute and 16 seconds to boot.
> But it claimed corrupted metadata and that the superblock was trashed
> and could not even mount the partiton.  I found this comment on the
> Gentoo installation instructions

XFS caches lots of data so you can lose stuff if you dont sync  it in
bigger chunks than you would expect. Corrupt metadata suggests a bug.
You may want to file it upstream in bugs.kernel.org. XFS should only
ever lose unsynced data.

> I'm completely confused now.  I have been under the impression that this
> was the main purpose for these (journaling) file systems?  I knew a guy
> that worked on BeOS and he claimed that you could flick the power on and
> off all day and it wouldn't lose data.  Am I doing something wrong?  Do
> I need to set a different mode or something on these file systems so
> that they can recover?

Ext3 gets intensive testing as does JFFS2 on flash (people have done 
thousands of random reboot tests on them). Red HAt doesn't do much with
reiserfs although the code should match the upstream tree.