Vmware and the Virtualization Gotcha's

There is this lab that has 4 different Win2k servers, each running a different application.
Server A - Mailserver
Server B - Intranet application with MS SQL db
Server C - Vpn server and backup
Server D - Test server

Along the way, the admin decides to put all these dated servers into a VM and slot it in to a high end Server from Dell. The whole porting process took around 2 weeks and when it was over,
everyone was happy with the new setup. No more additional switching cables and multiple monitors lyring around and the perceived energy savings cost was a bonus.

However one day, the mailserver began to feel very slow, Procexp (sysinternals) itself was myteriously taking up 45% cpu and more and even with the mailserver service stopped the pc still feels awkwardly slow. Rebooting didnt that mail server VM doesn't help either.

When i came in to help out in this scenario, the first thing i went thru was the list of VMs running in the server. One particular VM is taking up 26% of the CPU of the main server, however that should not be the reason why it would affect the mail server VM. Upon closer inspection however, i notice some native apps running on the test machine VM (26%) that is using up the VM's tcp/ip port very quickly.
It then became logically clear that this was the problem, pausing that VM immediately restored the other server's performance and that was like a 100% improvement.

I suspect the problem is because the main server is still just an OS with the normal limitation of the 65535 ports on a single ip and single network card. Since all the VMs runs on this machine , that test application was just blasting away the network resource, this turns the allocation of the real main server NDIS packets resources into an ugly situation where each of the VMs are queueing up to get its allocation.

Another case solve. Another Hamster Huey and the GooiKablooi award for virtualization.