Hello,
Everything Rodos said should be done or looked into. There is many ways to spec out what your Vmware systems are needed. One way is to base line your systems and find out what there low, average, and highend needs are on a daily basis, then you will be able to better spec out the resources on your resource pools / shares better. Also it is important to only use reservations on systems that really need to have that resouce garenteed at any time, and to use resource pool reservations / shares like mentioned earlyer.
One tool that may help you spec out your current system before the flip is the Vmware Capacity Planne. Wha this tool does is installs a thing agent on selected servers and then it monitors them for an extended period of time. Essentially the agent is like a perfmon in windows with a TON of conters tracking everything and dumping it into reports. So typically what people will do is install it and let it collect data for 1-2 weeks which will give you plenty of data / reports that show you your low, average, and highend requirements on your servers. Its very important to know this information as you could have a VM that really only needs 1GB of memory most of the day except it may need 3GB for just 1 hour a day durning a high load time. Knowing this will give you the ability to setup your shares better.
Another thing to take into consideration is your Virutal Switching and Port Groups. A good article on this topic is here:
8 nics - http://www.networkworld.com/community/node/36691
6 nics - http://www.networkworld.com/community/node/36359
4 nics - http://www.networkworld.com/community/node/35854
3 nics - http://www.networkworld.com/community/node/35640
2 nics - http://www.networkworld.com/community/node/35388
Also if you have those psyhical network card modules that have 2 or 4 nics on 1 psyhical pci card or module make sure to pair up opposite psyhical nics incase of a nic / module failure. For instace say you have 4 nics on your server.
pNic0 - Onboard nic
pNic1 - Onboard nic
pNic2 - Expansion module card
pNic3 - Expansion module card
In this expample your Expansion module card has 2 nics on the same module which is very common. In your virutal switching you would want to put pNic0 and pNic2 together in vSwitch0. Then put pNic1 and pNic3 together in vSwitch1, that way if your expansion module card dies your virutal switching will still function, where if you put all your vm's on the 2 nics that where on the module card you would be dead in the water.
Hope this helps, if you have any questions feel free to ask.
