joomla 1.5 + strange problem with virtual memory usage

[bejbi]

I have on server:

CloudLinux 2.6.32-379.5.1.lve1.1.9.6.1.el6.x86_64 on cPanel WHM 11.34.0 (build 7)

Server it is quad-Xeon, 8GB RAM, sas-disks 3ware raid

I have onlu about 30 account

LVE settings are default:
25%
1GB RAM

On two customers account (both have joomla 1.5 + virtuemarkt) there is a problem with very often Error 500 caused by Max Virtual Memory usage.

When I raise up memory to 2GB - after couple of days problem appears again.

When there is a problem with Max Virtual Memory usage - joomla-site has about 100 unique users online.

My php configuration is php 5.3 working as suPHP.

1. What can I do (how) to diagnose the resource consumption of customer's script ?

2. Is it possible that the problem is caused by suPHP ? (maybe change php to fastCGI will resolve the problem) ?

 

[iseletsk]

if you are using virtual memory limits -- then 1GB is not such a big number, and you might just increase it. Look at VIRT column in top to see how much each process takes up. Virtual memory doesn't map one to one to physical memory. So even with 2GB, if each PHP process takes up 200MB of virtual memory -- it is easy to overload.

If it is physical memory (RES in top output) -- then 1GB should be enough for most customers.

Of course you need to also monitor the server memory, and see if it being abused/if you have enough to handle the increase.