D&C GLug - Home Page

[ Date Index ] [ Thread Index ] [ <= Previous by date / thread ] [ Next by date / thread => ]

Re: [LUG] EXT2 filesystem: defragmenting

 

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Jeremy Pearson wrote:
|
| Coming from a Windows environment I'm used to performing regular
| defragmentation on FAT32 and NTFS partitions.

Very bad design, why did they not just run the defragmentation process
as a low priority task like say Veritas filesystems and hide the details
from the end user or admin?

| Do I need to defragment EXT2
| partitions in the same way? And if so, which tools do people use?

First why are you using EXT2? For most general purpose systems a
journalled filesystem gives better performance with quicker fsck if the
machine is ever shutdown uncleanly, try ReiserFS or ext3 next time it asks.

You can convert ext2 to ext3 but I think that more hassle than the
beginner will care for to save a few minutes next time there is a powercut.

The standard answer (search engines are your friend) is that no, the
filesystem allocation strategy used by this family of file systems is
smart enough that degradation is insignificant.

There maybe unusual disk activity patterns that makes an ext2 filesystem
less than optimal but it is not common to encounter this, in such cases
backup, newfs and restore is the standard procedure, in 15 years of Unix
admin work I've never encountered performance issues from filesystem
fragmentation (except on MS Windows).

A lot of that work was on systems with proprietary filesystems that were
prone to fragmentation (it can be better for performance to leave just a
little mess if you know someone will clean it up after you) but they had
a built in defragmentation task running continually.

The ext2 allocation strategy depends on having a lot of free disk space,
which is why most some filesystems reserve 10% of disk space for "root
only". Since disk drives are now much larger (relative to average, and
even maximum file size (often 2GB), 10% may be very wasteful - see "man
tune2fs" - "reserve block count").

Obligatory tunefs joke: you can tune a filesystem but you can't tune-a-fish
-----BEGIN PGP SIGNATURE-----
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFCXU0SGFXfHI9FVgYRAhknAJ9ZH48qvH/FvJm3bFOHXwWTpxNf+QCeJUla
fMlCfFs68KQKzK5MEB2TOIQ=
=MDbI
-----END PGP SIGNATURE-----

--
The Mailing List for the Devon & Cornwall LUG
Mail majordomo@xxxxxxxxxxxxx with "unsubscribe list" in the
message body to unsubscribe. FAQ: www.dcglug.org.uk/linux_adm/list-faq.html