VM performance on ESXI 5

[adotan]

Hi,

I have a DELL Server R710 and I would like to install about 18 VM servers. almost all of them are Centos Linux 64 bit and 2 are Win XP and Win7.

I have 48 GB of RAM and 2 CPUs with a total of 12 cores.

I would like to know if that can work?

should I worry more about CPU power (cores) or RAM?

I'm pretty new to VMWare ESXi and I'm not changing any configuration on the ESXI system.

should I?

I guess I'm working in a share mode...

so basically I need to know if I should have the same ratio of VM CPU and memory as I do with Physical CPU and Memoery machines?

Thanks a lot!!

Dotan.

[rickardnobel]

The vCPUs will likely not be a problem at all (if not all of your VM are very CPU intensive). Normally you could easily share many VMs on the same physical core.

As for RAM, how much vRAM do you plan to assign to each VM? Some overcommit is certainly possible, however to the same degree as "CPU overcommit."

[adotan]

Thanks!!

I'm using about 4 GB of RAM for each VM.

Dotan.

[weinstein5]

As Rick indicated CPU should be fine - I would also add that best practice is to allocate a single virtual CPU intially and add additional if needed -

In terms of memory that should be fine -  but like CPU you can start out with a little less say 2 GB and as needed -

[rickardnobel · Accepted solution]

adotan wrote:

I'm using about 4 GB of RAM for each VM.

With 18 VMs this will be 72 GB of RAM and if you only have 48 physical RAM in the host this will be kind of tight. There are many memory reclaiming techniques used by the Vmkernel, but this could be a bit too much.

I agree with Weinstein that you should start out with a lower amount of vRAM for each VM and increase if needed.

[adotan]

Thanks!!

[adotan]

Thanks you all!!

I'm much calmer now

[rickardnobel]

Good luck with your project!

(Discussion moved to the ESXi 5 forum.)