What's the /dev/shm?
 

[root@AntZ mnt]# df
Filesystem 1k-blocks Used Available Use% Mounted on
/dev/hda8 5399916 5026540 99068 99% /
none 95604 0 95604 0% /dev/shm
/dev/hda1 2557324 1996380 560944 79% /mnt/c
/dev/hda5 3783900 2799976 983924 74% /mnt/d
/dev/hda6 2557324 1145132 1412192 45% /mnt/e

A little searching goes a long way...

http://groups.google.com/groups?hl=e...TF-8%26hl%3Den

Here are two articles from Daniel Robbins, the Pres of Gentoo, on /dev/shm. It is used as devfs.

http://www-106.ibm.com/developerwork...ary/l-fs4.html
http://www-106.ibm.com/developerwork...l?dwzone=linux

They are part of a great series he did on advanced file systems. If you are interested in devfs, reiserfs, jfs and xfs, I'd recommend these. Go to:

http://www-105.ibm.com/developerwork...ment&Count=500

and scroll down to: Common threads: Advanced filesystem implementor's guide. You'll find 13 well written, easy to understand articles on them.