[NTLUG:Discuss] Starting over.

[Dan Carlson]

----- Original Message -----
From: "Scott Denlinger" <sbd at dakotacom.net>
To: <discuss at ntlug.org>
Sent: Thursday, August 29, 2002 12:26 PM
Subject: [NTLUG:Discuss] Starting over.


> . . .
> How much advantage does a journalling file system have over the
> traditional ext2 file system? I was using ext3 on my last system (Reiser
> before that, but that was problematic). If I do decide to use a
> journalling file system, should I use it on my /var partition as well?
> Or is there only an advantage to using it for boot/root partitions? My
> /home partition is on a separate hard drive, so that will stay ext3.
> . . .

The main value of a journaling filesystem is to avoid long fsck times.
Indeed, as near as I can tell, this is why they were invented.  If you have
small file systems then fsck times may not be a problem.  On large and very
file systems fsck times can become excessive, with hours not being
uncommon, which can be a major drag on system availability.

If your system partitions are small then you may not gain much by
journaling them.  If you can stand to give up a little performance then
there is no harm done by doing so.  It certainly makes sense to journal
large data partitions.

Although journaling file systems have overhead that affects performance
that non-journal file systems do not have, there may be other design
decisions and tradeoffs that affect performance even more.  For example,
Reiserfs has excellent performance for small files, and slower performance
for large files.  XFS is the opposite, fast for large files and slow for
small files.

Space efficiency varies among the file systems as well.  For example,
Reiserfs is more space-efficient than ext2/ext3 if you need to store a
large number of small files.

Dan Carlson