fsck

[Oliver Brandmueller]

Hi.

On Mon, May 15, 2006 at 03:21:24PM +0200, gareth wrote:
> On Mon 2006-05-15 (14:54), Oliver Brandmueller wrote:
> > Errm, You run fsck onto a r/w mounted partition on multiuser mode? If
> 
> yep

fsck has not been made for that!

> > this understanding of what your saying here is correct, then this is the
> > problem: a r/w mounted fs is a) never "clean" (in terms of a fsck that
> > takes some time to run)
> 
> these 2 particular cases take 1 or 2 seconds

OK, I was not clear enough: During normal operations what's on the disk 
and the view of the system to the filesystem are not necessarily the 
same - this is especially true for open files. No matter how long it 
takes for fsck to run, a r/w opened file will almost ever be in an 
inconsistent state.

Again: fsck is not for r/w mounted filesystems (except with -B for 
filesystems that support it - namely ONLY UFS2!). If you use fsck in 
traditional mode you will get unexpected results. And although fsck 
tries very hard to keep you from breaking things badly, you have a good 
chance to damage your filesystems if you use it improperly (no, I won't 
try if -y or -f will force a check on a mounted partition - I still need 
my filesystems).

Again, very loud and clear: DON'T DO THIS.

> > because it changes with every operation and b) should never be
> > checked in that way (that's exactly what fsck means when telling you
> > "NO WRITE").
> 
> ok. but it didn't used to do this, then it started showing up errors
> on /var, then /var and /tmp. meanwhile the 5 other partitions have
> never showed up errors. (/tmp & /var i spose happen to be small and
> volatile, but there is another small & volatile partition that doesn't
> show errors. also, the same behaviour shows when i (think) get rid've
> processes using /tmp)

After telling you, fsck is not suuposed to be run on r/w mounted 
filesystems in that way, I guess we can agree there's no room for a 
discussion like that, OK? I mean, you don't use the hammer for screws, 
do you?

- Oliver