Performance problem (high Load average) in Mail Server (fwd)

[Saurabh Bathe]

Mahesh Shinde wrote:
> 
> Dear Matthew,
> 
> We are using Trend micro's IMSS antivirus software and its processes 
> consumes normally around 1 GB of RAM. But this software is running from 
> last 6 months and we are facing problem of high load average from last 
> one month.
> 
> What I observed recently in "top" is 2 or 3 httpd processes are using 
> more that 25% of CPU resources and then load average goes on increasing 
> in the range of 10 to 20. After restarting "httpd" service load average 
> comes to normal.
> 
> What is causing "httpd" to suddenly consuming high CPU resources and how 
> to find out where is going wrong?
> 

This could be due to very large IMAP mail boxes.
Check that when the load goes very high, which mailboxes are being 
accessed through web. mailboxes > 600-700 M and web clients like 
squirrelmail, could be a problem.

To check if this is problem, try accessing the same same mailbox with a 
mail client like Mozilla Mail/Thunderbird and see if the server load 
increases again.

This way we can see if this is a web clinet's problem or that of the 
mail server.

//Saurabh