Python memory management <-> virtualized server environments

[gravityzoo-dmo]

Hello everyone,

I was wondering if anyone here has had any experience in running
Python in a virtualized server environment?
The reason I'm asking is the recent thing I noticed when running my
server application (written in Python + Twisted);
The memory of the server application seems to only grow, and not give
back memory space to the OS. I realize that this won't be a problem on
a single physical server, but I'm curious of the effect this behaviour
has on a virtualized environment.
Could anyone provide me with a little more insight please?
Thanks in advance!

Dirk