JFS in Ubuntu

[Rashkae]

James Gray wrote:

> Actually, XFS is fairly pervasive on my systems ;)  It performs well and
> is robust.  JFS will improve with time and the jury is still out on ext4
> (again, time will tell).  For today though, I'd say XFS is a good
> alternative to ext3 and although you can't shrink XFS (it can grow
> though), it has a couple of stability issues on LVM volumes, and it's
> metadata modification when creating and deleting directory entries isn't
> as fast as some (but can be improved
> http://everything2.com/index.pl?node_id=1479435)...I still like it.
> 
> HTH,
> 
> James
> 


XFS is, all around, the best performing filesystem.. however, it has
*big* caveats that make it a poor recommendation to throw around at
random people.

XFS delays flushing data to disk for a long time and doesn't write
meta-data/data in ordered fashion.  What does this mean?  It means in
the case of an unclean shut-down, however it comes about, files that
were being written but not flushed to disk will have be padded with null
characters.

This can be problematic in /home because some applications don't write
their configuration files in a sane manner (ie, never overwrite an
existing file until the data is flushed to disk) and will potentially
nuke your settings/preferences in the case of an unclean shutdown.  It's
also very likely going to corrupt any data mirror (ftp mirror for
example), since those usually rely on filesize and datestamp to compare
sets of data.  In the case of XFS, with an unclean shutdown, they only
way to tell which files might or might not be complete is to do an md5
check on all of them.

EXT3, while not the fastest or shiniest filesystem, is the default
filesystem in use by *all* distros for a reason.  It's reliable and
uncomplicated, and unless you are concerned with how long it takes to
delete files, the performance is not really bad.  (You might have to add
the dir-index option if you have directories with large number of files,
but that's another topic)