VMware Analysis..

[Rohail2004]

Guys... I am looking for some help.

We have 10 Hosts, 8 CPU, 2.66GHZ with 16GB each memory on it. We are currently running 44 VM's on those 10 Hosts. They are in two different clusters. I am being told to find out how many more physical servers I can add into my existing VMware environment. What is the best way to figure this out? Should I upgrade memory from 16GB to 64GB and that would help a lot to add least 20 more VM's.

any suggestions would be highly appreciated.

[weinstein5 · Accepted solution]

Not knowing the existing VM's configuration or if the CPUs are multicore my gut feeling is you probably can add the 20 new VMs with out issue - to confirm take alook at the existing resource consumption on your ESX servers - then try to estimate how the resources the the new VMs will need - and you can base your decision about memory on those results. If you are running short on resources my experience has shown that this typically due to not enough memory or disk resources -

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[azn2kew]

Typically, if you architect your ESX host capacitity by 4-6 VMs per core. 8 cores x 6 = 48VMs per ESX hosts. This numbers is not fix because each servers is different in terms of memory usage. Most standard server can run fine with 1024MB of RAM and some are 2048MB and so forth depends on your desires.

10 Hosts with 8 cores and 64GB RAM:

10 x 8 cores = 80 cores

64GB x 10 = 640GB RAM - 10GB for service console RAM = 630GB RAM

80 x 4 VMs = 320 VMs total. With basic calculation, you can at least run 320 VMs each with 2048MB RAM. You can of course run more if those only require 1GB RAM. Make sure you have enough bandwidth for your networking and SAN I/O.

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Regards,

Stefan Nguyen

iGeek Systems Inc.

VMware, Citrix, Microsoft Consultant