Help! 10.04 LTSP becomes very slow to load and operate.

[john]

Hi David,

Can you describe how older clients (or possibly just compaq clients)
make things worse? Do you know why this might be. I have a number of
older clients on the network and would be very interested to know if
they are actually degrading the LTSP experience for more modern
clients in some way.

One thing I've noticed on any client you care to name is that it will
often become "diconnected" from nbd somehow, and although it will
continue to run, it will chatter frantically over the network to the
server.

Thanks!

John

On Tue, Oct 26, 2010 at 11:12 AM, David Hopkins <dahopkins429 at gmail.com> wrote:
> Jim,
>
> Sounds very familiar to what I was experiencing ... check via top if
> dbus is using 100% of cpu in which case this could be the issue I saw
> with nofile defaulting 1024. (ps -u messagebus for the PID, then cat
> /proc/PID/limits to see what the current limits are)  .. the load
> averages were low but the system was almost non-responsive.
>
> Also, if you are nfs mounting home directories, check the settings for
> wsize and rsize.  I've found that 8192 works well with Ubuntu but my
> prior setting of 32768 caused all kinds of random issues due to slow
> file access.
>
> I also found that with older hardware (specifically older Compaq
> systems and systems with less than 128Mb memory) I could get one
> misbehaving client which would slow everything down tremendously.
>
> There was also an issue with flash and needed to set a couple of flags
> for plugin-container:
> http://kb.mozillazine.org/Plugin-container_and_out-of-process_plugins
> ... I just made the changes directly in firefox.js as that was most
> expedient.
>
> And ... I found that I also needed to delete a lot of the old config
> files for users when I migrated from K12LTSP based on RHEL4 to Ubuntu.
>
> Just my guesses ...
>
> Sincerely,
> Dave Hopkins
>
>
> On Tue, Oct 26, 2010 at 1:53 PM, Jim Christiansen
> <jim.c.christiansen at gmail.com> wrote:
>> I've been fighting a huge slow-down of our current 10.04  ltsp 34 client
>> system.  I'm not running local apps, the server has 8 gigs of ram and a 6
>> core processor.  The cpu load is rarely over 30 or 40 % and swap is never
>> used.  One nic on the server attached to a 100 megabit unmanaged switch.
>> The slowness comes unexpectedly and a restart may not improve the situation.
>> The wierd part is if I fire up our old K12LTSP server things work normally
>> as ever...
>> Does anyone know how to diagnose this problem?  I don't know if our network
>> is saturated/maxed out, if the wiring has gone downhill and become
>> problematic again, or if I have an internal server setup mistake.  I'm on an
>> internal 192.168.1 subnet and think I've edited the system files properly.
>> Thanks,  Jim
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