Ext3 users - Oct 2001 - Recreate journal after switch between ext2/ext3 ?

Hi,

After mounting -t ext2 an ext3 partition, working with, 
do I have to recreate .journal when I remount the
partition as ext3 ? Thanks !

Liu

On Oct 24, 2001  00:20 +0200, Qing Liu wrote:
> After mounting -t ext2 an ext3 partition, working with, 
> do I have to recreate .journal when I remount the
> partition as ext3 ? Thanks !
No.  You can safely mount an ext3 filesystem as ext2 as much as you want,
as long as the ext3 filesystem was cleanly unmounted (empty journal).  If
it is not cleanly unmounted, it will refuse to mount as ext2 until e2fsck
is run on it.

In all cases, the ext3 journal will exist until "tune2fs
-O^has_journal"
and e2fsck is run (or if your journal is corrupted and e2fsck removes it).

Cheers, Andreas
--
Andreas Dilger  \ "If a man ate a pound of pasta and a pound of antipasto,
                 \  would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/               -- Dogbert

Hi,

On Wed, Oct 24, 2001 at 12:20:15AM +0200, Qing Liu wrote:
 
> After mounting -t ext2 an ext3 partition, working with, 
> do I have to recreate .journal when I remount the
> partition as ext3 ? Thanks !
No.  ext2 will just ignore it: it will still be intact next time ext3
wants to use it.

Cheers,
 Stephen

Andreas Dilger wrote:
> 
> On Oct 24, 2001  00:20 +0200, Qing Liu wrote:
> > After mounting -t ext2 an ext3 partition, working with,
> > do I have to recreate .journal when I remount the
> > partition as ext3 ? Thanks !
> 
> No.  You can safely mount an ext3 filesystem as ext2 as much as you want,
> as long as the ext3 filesystem was cleanly unmounted (empty journal).  If
> it is not cleanly unmounted, it will refuse to mount as ext2 until e2fsck
> is run on it.
OK, thank you both for the responses. Another newbie question:
what .journal contains ? 
If I understand well, it is supposed not to be modified 
after it is created. I did (somedays ago): 

/var/tmp# cp /.journal /var/tmp/journal-orig-hda4
/var/tmp# ls -l /.journal journal-orig-hda4
-rw-------    1 root     root      8388608 Oct 13 00:17 /.journal
-rw-------    1 root     root      8388608 Oct 20 08:20 journal-orig-hda4

and today,

/var/tmp# cmp journal-orig-hda4 /.journal 
journal-orig-hda4 /.journal differ: char 27, line 1

So I am a little confused. /.journal was created under linux-2.4.10-ac11
with e2fsprog-1.25. 



Liu