new ESX Servers

[ful56_uk]

Good Morning all,

I am going to be buying 3 new servers with dual quard core processors and 16GB. These servers will be on a SAS san 1.2TB.

I was woundering how many vm's can i put on each host? One VM will be a sim server as well.

Can any one give me some guide lines please.

[tmcd35]

If you work on two VM's per core then you should get 16 VM's running on each without probs. Certainly used very similar set-up and ran around 12VM's without a hitch. Depending on workload of the servers, you may get more, 25-30.

Don't overload the hosts though. Just because you can run 30 VM's on each server doesn't mean you should. To should run the servers at 2/3 capacity so if one goes down the other two can take up the workload. So I'll say no more than 8-12 VM's per server, and if one goes down the other two should cope with an extra 4-6 VM's.

[ful56_uk]

Cheers sounds good, ill get writing down what servers i need on what boxes.

[teejay]

If you are running that many VM's I would possibly increae the memoery a bit more.
I try to run the servers at around the 50% load mark, as if you go above this the power used and the heat generated increse tremendously.

[RobFuller]

RAM RAM RAM, there is no real rule about how many you can run it real depends on the resources each VM needs.

Get as much RAM as you can as that will certainly go way before you use all your processing power.

Virtualize bit my bit and watch carefully your host servers to see how there coping and how much resources you have left. Make sure you have enough left for redundancy if one were to fail.

[tmcd35]

I try to run the servers at around the 50% load mark, as if you go above this the power used and the heat generated increse tremendously.

Just a note - from the VMWare training course - the power/heat/environmental savings involved with Virtualisation come from running less physical servers not from running the servers with a low work load.

It is better, from a virtualisation point of view, to run 2 physical servers at 80-90% workload than 3 servers at 50% workload. Obviously disaster recovery needs to be taken into account, so running a server at 90% may not be ideal for that reason.

I'd say, personal opinion, that your average virtual server should have a workload in the region of 70% (processor/memory usage).