At work I was playing around w/ calculating all the free space and ram configurations on the VMs on the older VMware cluster we are looking to replace. I dug up an old VB/WMI script to pull ram configuration and was testing it.. and I found this interesting and I assume performance degrading find.
It looks like if you assign ram to a VM in # non-divisible by 1024 the VM kernel will emulation MORE ram slots to ‘emulate’ the need to create the exact amount of ram assigned to the VM.
But from the WMI script I pull it has this ram slot configuration..
This VM below has assigned 7800 MB or RAM. If we assigned 8192 MB of ram, which I assume would be emulated as (4) – 2048 G chips. I am unsure of what impact this would have either way.
I assume its non-advantageous to have the kernel emulation more slots when its not really needed.. but it may be splitting hairs. Does this matter at all?
My .vbs scirpt is attached. I am also seeing incositant results where some VM boxes emulate 16 ram slots, but it might be only a 2G VM with 14 empty slots. Then other VMs with 2GB will show just a 2 slot VMs? Why would this be?
*Note - This example is from a VM hardware type=4 on a vSphere4 U1 host on a Dell 2950 running Win2003 Ent SP2.