Help! 10.04 LTSP configuration using only one nic

[Jim Christiansen]

Hello,

I've just had an aging server fail to start up and need to get to the bottom
of another problem on another new server running Ubuntu 10.04 LTSP before
attempting to do another install.  We lost one server in the Library late
last June- rgreat timing and another one just today that served my classroom
has failed to start up-  Both are 5 years or older.

My old Centos LTSP server for our Library died near the end of June.  My
students had been playing with a new 10.04 64 setup and had it serving 32
bit fat clients, but really slowly.  One of the students altered something
in iptables to make it function and I wonder if this could be the problem.
 Grepping my history for iptables shows:

 49  sudo iptables --table nat --append POSTROUTING --jump MASQUERADE
--source 192.168.1.0/24
 50  sudo sh -c 'iptables-save > /etc/ltsp/nat'

This was done, apparently, to allow the system to function with one nic.

The system is sitting on a 100 megabit network with 26 clients.  Only 1/3 to
2/3 of the clients will boot right off.  The others will linger with 4 four
little streaming dots in the middle of the screen for minutes until the log
in screen appears or they fail with errors:

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
INFO: task modprobe:436 blocked for more than 120 seconds.
"echo 0 >... same as 1st line
INFO: task udev-configure-:936 blocked for more than 120 seconds.
"echo 0 > ...same as 1st line
INO: taskhdparm:1020 blocked for more than 120 seconds.
"echo 0 > ...same as 1st line
INFO: task S32ltsp-client-:1027 blocked for more than 120 seconds.

It doesn't seem any better it I boot fewer clients or more... They just
don't all start up reliably.

The clients run awesomely once students get logged on.

Does anyone know what the problem could be?  I'm wondering if the natting is
the problem or if I have other issues.

Thanks everyone,

Jim
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