[ILUG] Slow client performance

[Niall O Broin]

On 27 Aug 2004, at 12:19, Kevin Philp wrote:

> We have a small network with a server providing NIS, DNS, NFS and proxy
> services. Both run on Mandrake, the clients are Mandrake 10 and the 
> server
> Mandrake 9.1. One user has noticed that her machine sometimes gets 
> very, very
> slow. A quick look at top doesn't show anything gobbling up huge 
> amounts of
> RAM or CPU time but it can take 30-40s to open OpenOffice, which is 
> installed
> as a local application, so I don't see it has a network issue. However 
> it
> takes 2s to open OpenOffice on the server which is the same hardware 
> but with
> 512mb RAM instead of 256mb on the clients. When the client slows down 
> the
> server continues to zoom along as usual unaffected. The users are 
> using KDE
> as their desktop and if rebooted the machine appears to work fine for 
> a while
> and then grind to a halt again....any ideas?

RAM, RAM, ramity RAM. The box in question doesn't have a load of  RAM 
(in terms of running KDE and OOo), and as time goes by in KDE more and 
more memory is used, and hence more and more swap (reboot the machine, 
and watch the swap usage (top works nicely, but there may be a KDE 
graphical thingy too) as the machine is used for a while).

This is an issue with the 2.4 kernel, which will use swap rather than 
reclaiming pages from applications, although this often leads to poor 
application performance. With 2.6, you can adjust some kernel 
parameters which control the kernel's 'swappiness'  and can improve 
perceived performance in such situations.

The solution is to buy some more RAM for the client, or use 2.6 and 
play around with the 'swappiness' parameters.


Niall