How to calculate utilized vCPUs from my physical CPUs

[majidbaigs]

Hi,

I have 10 ESX host with each server 12 Physical 3.07 Ghz CPUs, and each server is having 96 GB of memory.

Now the question is how many VMs i can create with the configuration of 4 Core and 4 GB memory? Below screenshot from one of our ESX server.

Thanks

Mirza

[Sateesh_vCloud]

Before going to finalize number of VM's - you need to answer list of questions:

1)   What is your fail over policy for ESXi? (How much capacity you want to reserve?)

       Let us say 25% of CPU and 25% Memory

2)   How much growth you are expecting in next 1 year? (some times people ignore)

       Let us say 10% of Total Capacity

3)   What is agreed peak usage in production?

       Let us say 80% at any time

4)    What is the overhead memory in Cluster?

       Let us say 5% of Total

Finally:         Total RAM = 10 x 96 GB    960 GB

                    80% peak usage = Usable memory is 768 GB

                    5% over head =  After over head around 720 GB

                    25% fail over =  After fail over it is 540 GB

                    10% growth = After growth around 496 GB

Total VM's = 496/4 = 124 VM's

NOTE: All these calculations are generic and you need to understand Customer requirements first and CPU is most of the time sufficient

[vfk]

Also, don't forget to size your storage accordingly,  swap space = configured memory - reservation.