memory recommendation for guest os

[engyaz]

hi guys,

i need some advice

i have a cluster of vsphere 5 made of 2 servers on each server i will have about 5 VM

1) domain contoller 2008 standard editon + dhcp+ dns

2) exchange 2010

3) file server

4) primavera

my question is what is the recommended memory and cpu configuration for these VM? i am a little bit confused

what if i don't configure any limits and reservation and let everything to default? what is the week point in this configuration? if i let everything to default each VM will not use memory a cpu as she needs?

thanks for you clarification in advance

[weinstein5]

Welcome to the Community -

1) VM Configuration - It will depend on the how large environment are you trying to support - Best practice is to start with a single vcpu and add more if needed. In terms of memory look at what the applications require - but once again this will be again determined by the load

2) As a start do not set limits or reservations - they are useful when you have a VM that will always need a certain amount of CPU or memory -and in that case you will set a reservation

3) Yes if you leave the settings at default the vms will only use memory and cpu cycles as needed

[michaelstump · Accepted solution]

To add the memory advice... Many people allocate memory to VMs that will never be used, and in the end you consume your host's memory much quicker than necessary. Start low when allocating memory to a VM. Adding memory is simple to do later on, after you've collected performance data on the operation of your host. The Performance tab will show you what's going on.

mike