I have a head-scratcher of an issue here I hope someone can help with.
We have a bunch of .NET websites hosted on VMWare Server guest systems using VMWare 1.0.8 and VMWare 2.0.1. The back-end of these website are three Microsoft SQL (2000 and 2008) servers also running in Virtual Machines.
My hosts are all Windows Server 2003. The Guests are mostly Windows Server 2003, but I have a few Windows 2008 VM's and a handful of CentOS linux VM's as well. The hosts are all Dell servers running dual-Quad core procs and 8GB of RAM each. I have 10 hosts and around 30 VM's running on those hosts.
For a while now we've been having some performance issues with our sites. The sites have been losing sessions, temporarily losing access to the SQL server and website performance has intermittently been terrible. I have monitored the VM and the host using Task Manager during the times when performance is bad and the CPU is usually consistently around 25% or so and the memory usage is normal and the networking usage is usually under .2%.
To make matters worse, the results have not been constant. I can have one session that runs so slow it's almost unusable, but open another session from a different workstation or browser and have the site perform fine from there.
We have recently installed IPSwitch WhatsUp Gold to monitor the systems inside the network. It is currently only running a simple PING test and it is returning some interesting results.
I can now see that I get alerts saying that my VM's are frequently down. They are often not down for very long, but the flow of alerts is constant. Furthermore, it is only the VM's that are throwing the alerts. The hosts seem to have no problems.
Does anyone know if the VMWare Server products utilize a "Virtual Switch" like the ESX version do?
If I communicate between VM's on the same server, does that traffic hit the physical network, or is it just handled within the VMWare networking components?
Most importantly, I need to know how to optimize my VMWare networked environment and need to stabilize my site.
Also, has anyone had experience upgrading from VMWare Server to ESX? How much of a performance improvement did you pick up?
Thanks!
