very slow login times

[Robert Arkiletian]

On 11/6/08, rmcdaniel at indata.us <rmcdaniel at indata.us> wrote:
> Here's the scoop this morning.  I have run all updates on the server and
> rebuilt the client /opt/ltsp/i386 to make sure that I had all current
> updates applied.  I am still seeing excessive bandwidth used on the
> switch with just 1 thin client attached and booting off of the server.
> To eliminate any network suspicion, I have a regular pc with XP running
> off of the same switch in the lab.  When I access a youtube video with
> the thin client, I max my switch port at 100% utilization with 100%
> unicast packets.  When I access the same youtube video with the pc, the
> switch utilization is very low 2%.  It seems like some great
> inefficiencies in the networking protocols on the thin clients.  I can

Ron this is normal. Youtube is not a good test to see if your setup is
over utilizing network bandwidth. Youtube will saturate a 100Mbps
connection. I have tried running a youtube video as a local app and
the network usage drops dramatically. Here's why.

Flash is a highly compressed video format. The SERVER decompresses it
and THEN pushes the decompressed stream to the X server on the client.
This is inefficient for 2 reasons.

1) the server is taking the cpu load to do the decompression
2) your lan is being saturated with decompressed video image data

Try running firefox as a local app and watch the network utilization
on gnome-system-monitor

This is a big reason why local apps is so important.

-- 
Robert Arkiletian
Eric Hamber Secondary, Vancouver, Canada
Fl_TeacherTool http://www3.telus.net/public/robark/Fl_TeacherTool/
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