What is /.journal?

[Kostas Sfakiotakis]

Greetings Rick ,

Rick Stevens wrote:
> On Tue, 2005-12-27 at 20:04 +0300, A.Fadyushin at it-centre.ru wrote:
> 
>>The /.journal file is created when the _existing_ EXT2 filesystem is
>>converted to EXT3 filesystem. 

I  never had ext2 filesystems . Anaconda created  ext3 ones from scratch .

That file contains the filesystem journal
>>used by EXT3. The file is only created during the conversion EXT2->EXT3
>>because it is impossible to create separate region on the existing EXT2
>>filesystem for the journal - therefore, the journal is placed in the
>>file /.journal (which is similar to regular files but is unremovable
>>under EXT3). When the EXT3 filesystem is created anew, the journal is
>>placed on disk separately from the space used for files' data, so there
>>is no need to reserve that space via special file entry.
> 
> 
> Perfect answer, Alexey.  That is correct.  If you convert an ext2 to
> an ext3 filesystem, the system must put the journal somewhere, so it
> creates a ".journal" file in the root of the filesystem and puts the
> journal there.  A freshly created ext3 filesystem reserves space OUTSIDE
> the namespace for the journal, hence it doesn't show up in a directory
> listing.
> 
> It is important that you NOT delete the ".journal" file (permissions are
> set so it's difficult to do anyway), because if you do, you will cease
> to have an ext3 filesystem and you may even have issues mounting it
> since the ext3 module wants a journal and won't be able to find it.


So i guess you mean that after the ext3 filesystem is created , this
file get's deleted , so it ceases to exist . Well i mean all my filesystems
are ext3 ones but a /.journal file is nowhere to be found