How to tune Memory allocation in an existing VMWare ESXi 5.1 environment
Posted on 2013-10-22
Firstly, everything is working pretty well. I have 3 Dell R710 servers each with 128Gb of RAM. All together, I have approximately 45 virtual machines. Till now I've been pretty generous with the RAM allocations, but now were starting to hit the ceiling as far as RAM goes.
I'd like to analyze the actual needs of the virtual machines, and adjust RAM allocations accordingly. I've read a bunch from VMWare, various blog posts, EE of course, and in the end I think I have a good approach, but I just want to vet it.
So I have IPMonitor setup to watch each of my VMs, it records the Physical Memory consumption every 5 minutes and I can create a report looking as far back as I want.
So for example if I have a Citrix Web Interface vm with 4Gb of RAM allocated, IP Monitor (And the OS) report over 80% free memory over the course of the previous month. So it is only using 820Mb of RAM and I add the VMWare overhead which is reported at 46Mb, and add 30% for breathing room which comes to 1.1Gb of RAM, am I golden? (Based on some general recommendations that your 'average' memory consumption shouldn't exceed 70%)
Let me know if I'm going about this right.
Thanks a ton