Amazing! I'm still a little thick-headed about exactly what tmpfs does, but it seems to be working! Here's what I did:
1. I'm now using Xandros, because it's easy to install and configure, and
runs KDE so I can use the KDE Kiosk Admin tool. I created an "all" account
and configured its profile with the Kiosk Admin tool (from the root
account) so that patrons can't bring up context menus, etc. from the "all"
2. I added the tmpfs fstab entry. Here's my /etc/fstab file:
# /etc/fstab -- static file system information
# auto generation: on
# generated by: /sbin/etcdev2fstab
# NOTE: to make this file readable, it has been formatted for 132 columns
#<device> <mountpoint> <fstype> <options> <dbg> <pass>
/dev/hda2 / reiserfs rw 0 0
/dev/shm /home/all tmpfs defaults 0 0
/dev/cdroms/hdc /media/cdrom0 iso9660 ro,nosuid,nodev,exec,user,noauto,async,unhide 0 0
/dev/floppy/0 /media/floppy0 auto rw,nosuid,nodev,exec,nouser,noauto,async 0 0
proc /proc proc rw 0 0
usbfs /proc/bus/usb usbfs rw,devmode=0666 0 0
/dev/hda1 none swap sw 0 0
3. I rebooted the machine and played around to see how it works.
If I login as all and make changes (delete a Desktop shortcut, for
example), then reboot, the changes do not remain. If I only log out and
log in, the changes remain until I reboot. If I make changes with the KDE
Kiosk Admin tool as root and then reboot, changes remain (this is how I
want it anyway, yay).
As root, looking at my filesystems I see / and /home/all. The second is
obviously my tmpfs mount, which wasn't there before I added the fstab
entry. If I make changes in the /home/all mount as root and then reboot, changes do not remain.
What is confusing to me is that if I make changes as root to /home/all
under the normal / filesystem, the changes still do not remain when I
reboot. Shouldn't they remain, since they are "under" or "before" the
tmpfs mount? I assume the all profile is actually looking at the /home/all
tmpfs mount, rather than /home/all under the / filesystem, and that is why
changes don't stick when made from the all account. But why don't changes stick when made as root to the /home/all folder under the / filesystem?
I am getting one error message when I login as all since I added the fstab
First Run Wizard
Creation of date time page failed.
File: ../../../src/desktop_wizard/desktopwizard.cpp Line: 331
Please report this to Xandros as a bug
This is probably a Xandros issue, not a Linux issue. I searched and didn't find any desktopwizard.cpp file in my filesystem.