Just looking advice from someone who has maybe gone down the virtualization. Basically we wanted to get a start on virtualization so bought an EMC clarion san & 2 dell poweredge 2950's for the esx hosts and a used an existing server for the virtual control centre. We had consultants set this up for us and create virtual machines etc. I didnt know how easy this was or i would have attempted it myself. I have since used the converter to test a couple of our existing servers and they are running fine now as well. The problem is where to go from here. The consultants say they need to come in and run vmware capacity planner to see what else is suitable to run on the hosts. I know we dont have access to this utility - but do you need to do this. I am basically looking a sensible approach to determine what servers to virtualize. We have over 70 and i know not all of them will be suitable. It is just to know is there a sensible place to start.
The consultants are correct. You should get some form of capacity planning done to determine which Physical systems are the best candidates for virtualization. Actually getting in the hardware before you go down this road may have been putting the cart before the horse, but it is a start. You need to look at the Disk/CPU/Network/Memory Utilization over a period of time for each host and determine if that host can be virtualized or not.
Your limitation on what can be virtualized will be the amount of memory in the Dell machines. You may not have enough to virtualize as many systems as you desire. Take this example: Your Memory Utilization for your servers is 3GBs, if your machines only have 8GBs each, that means you could virtualize up to 2 machines per HOst, or only 4 VMs for the two boxes. Yet if your memory utilization is only 512MBs MAX you could virtualize 15 hosts per system (you need to leave some memory for the vmkernel and SC). But that is just memory, now throw in DIsk IO, Network IO, CPU utilization and you may still not get to where you want. However memory is the biggest hit.
How many NIC Ports/FC-HBA ports on the systems will also make a difference, for full redundancy you want at least 2 FC-HBA, and 6 Physical NIC (pNICs) ports on the machines. If you are running DMZ/Production VMs on the same host (not recommended by the way) you want to have at least 8 pNICs for fully secure, redundancy, and performing systems. Did the consultants do some disk planning on the ESX Servers before installing, or take the default install? If so then you may have too little disk space assigned to the Service Console partitions. Or not enough to do good backups, etc. You need to consider backup requirements with your Virtualization servers as well....
Edward L. Haletky, author of the forthcoming 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', publishing January 2008, Copyright 2008 Pearson Education. Available on Rough Cuts at http://safari.informit.com/9780132302074
We also had consultants run the Capcity Planner and they helped us in recognizing about 170 of our 200 Physical servers which Could be Virtualized.
So i Would say it;s good practice to have it done using specialized tools if possible.
Else You can just try to pick those machine which are less disk intensive as i feel most of the stuff can be virtualized except those application which have high disk I/O.
I have tackled a number of consolidation projects using PlateSpin products, with a little bit of your time you could have PowerRecon running on your DC, this is a powerful tool that you should read up on. VMware's Capacity Planner is a great tool but PlateSpin have been in this space for some time now and it's something you can handle yourself with a little training perhaps.
If you need further impartial info mail me.
this doesn't answer all your questions but it might be a starting point
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