libvirt users - Oct 2012 - LXC guest memory recycling under RHEL6

Hello, I'm running a LXC guest using libvirtd under RHEL6. The guest
has this particular memory behavior that I'm unable to explain.

I've the following memory settings for this guest's memory. Inside the
guest I'm running a Apache webserver serving PHP scripts and static
content.

  <memory unit='GB'>2</memory>
  <currentMemory unit='GB'>2</currentMemory>
  <memtune>
    <hard_limit unit='GB'>2</hard_limit>
  </memtune>

Now, when querying using virsh dominfo I see the amount of used RAM
increases every second and it gets to the point where it reaches the
limit causing the guest to be unresponsive. The current solution is
destroying the guest process (virsh destroy) and starting again, but
the behavior repeats again.

As I understand what is happening is that the amount of memory used by
Apache's processes (4 mpm forks) is never released so every request
causes more memory comsumption reaching that point. If I'm correct on
this what can I do to handle it?

thanks!

-- 
Rudy Godoy
http://stone-head.org