Ubuntu-ltsp is not a mess! [ but needs some polish :) ]
Pierre Yann Baco
pbaco at carlit.net
Thu Sep 11 13:07:23 BST 2008
My name is Pierre Baco. For the last 3 years I've installed LTSP based
solutions in approx 30 elementary schools for a total of +/- 700 thin
clients (mainly recycled old fat pcs + PXE network boards).
First sites used woody+LTSP4.2. Last june, the local education
department required all schools to be updated to Ubuntu Hardy + LTSP5.
I've done so (inc. adding an extra 64Mb in some (too) thin clients) in
august. Globally, the new solution runs fine. LTSP5 is easy to
setup-configure, it supports a large set of hardware, local USB-sound
works like a charm.
However, there is still a "mini" list of problems for which I've not
found a complete and clean solution. I do known some of these problems
are not directly linked to LTSP code/setup, but their effects have a
deeper impact in a LTSP based site (and in schools where Msoft is a
hard-to-break monopoly). Here is the list:
- Not localized. This is a real issue in french (and I guess others)
elementary schools. "Username" and "Password" are simple english words
(and we french need to improve our english), but there should not be the
first two words displayed by a computer in a french school.
- NumLock off: Can't force NumLock ON prior to enter username and
password. 8 years old kids (and their teachers...) always forget to
press NumLock prior to enter their (often birtdhay date based) password,
and login fails until they realize it (sometimes they don't!)
- persistence of ldm screen after server shutdown or network failure:
When the server is down (or the link between it and a thin client), ldm
continues to ask gently for username/password "as usual". There's no way
for a user to know something is wrong "on the other side". You can't
imagine the number of support calls I get from users entering 20 times
in a row their login/passwords (as they can't check the server status
located elsewhere). With LTSP4.2, thin client gdm screens were
locked-greyed out when the network or the server was down.
- Can't use GNOME administration utilities (users-admin etc.) on a
thin client. (same happens within NX remote sessions). Works only on
server console. It's also a real issue when the server is in a locked
room. I've found a couple of threads about this, but could not find a
real solution for it. I've tried almost all polkit-gnome-authorization
configurations: still no success. And don't even think to ask a teacher
to run useradd/userdel from command line to add 30 login names every
3°) Process cleanup:
- This list has received many posts about this (persistence of
processes after thin client logouts). There are workarounds, but no real
fix yet (or workaround included in a .deb update). My quick and dirty
workaround: crontab based reboot every night.
- same (gnome) problem with the ~/.gvfs still mounted after user
logout. This generates a problem with userdel and/or other user
administration utilities (can't delete user homedir).
4°) Sound compatibility with some educational programs:
- ChildsPlay and tuxpaint are not very happy with remote sound (no way
to quit the application except big red switch, (leaving CPU eating
processes). There's a workaround (manually disable esound in the launch
script), but it would be nice to have an add-on deb package (like
"tuxpaint-ltsp.deb") to integrate the workaround in the general
Having this list fixed would eliminate 90% of problems encountered in
the schools where I've installed Ubuntu+LTSP5.
No need to say I'm ready to help and contribute (more details,
additional testing, translation, etc.)
And "Chapeau Bas" to those working hard to make Ubuntu+Ltsp the great
solution it is today despite grumpy users like me.
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