> Applications that are /dev/shm-aware usually take care of it 
> automagically,
> there's nothing to configure.  However, you can get better 
> performance out
> of some applications by also mounting /tmp as a tmpfs filesystem.

However, MailScanner, which appears to be shm-aware, wasn't so as a default.
I had to mount it to shm:

[root@ns1 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/md1              6.0G  1.1G  4.6G  20% /
/dev/md6               99M   12M   83M  12% /boot
none                  1.5G     0  1.5G   0% /dev/shm
/dev/md4              135G  2.5G  126G   2% /home
/dev/md2             1012M   40M  921M   5% /tmp
/dev/md3              4.0G  302M  3.5G   8% /var
none                  1.5G   32K  1.5G   1% /var/spool/MailScanner/incoming
[root@ns1 ~]# cat /etc/fstab
# This file is edited by fstab-sync - see 'man fstab-sync' for details
/dev/md1                /                       ext3    defaults        1 1
/dev/md6                /boot                   ext3    defaults        1 2
none                    /dev/pts                devpts  gid=5,mode=620  0 0
none                    /dev/shm                tmpfs   noexec,nosuid,rw
0 0
/dev/md4                /home                   ext3
defaults,usrquota,grpquota        1 2
none                    /proc                   proc    defaults        0 0
none                    /sys                    sysfs   defaults        0 0
/dev/md2                /tmp                    ext3    defaults        1 2
/dev/md3                /var                    ext3    defaults        1 2
/dev/md5                swap                    swap    defaults        0 0
# this is from MAQ:
none /var/spool/MailScanner/incoming tmpfs defaults 0 0
/dev/hdb                /media/cdrom            auto
pamconsole,exec,noauto,managed 0 0

BTW, it appears I was hasty to say I have /tmp mounted as tmpfs.
Now, I recall someone told me off, arguing it will break things, such as yum
How serious is it?
I'd really like to make as much apps work from tmpfs as possible, for
obvious performance advantage


Arthur Sherman