Check out this topic on the VMTN forum by Gabrie. It’s a good read about how many vm’s one would dare to run on an ESX host.
TexiWill:
This really depends. I know companies that are doing no more than a 10:1 or 20:1 compression, but there are other companies with 50+ VMs running on one box (at the time it was a DL760 with 8 CPUs and 64GBs of memory. I do know that the max vCPUs you can put on a system is still 8 * pCores and the larget box I have seen is the DL580G4 with 4 quad cores (16 cores) and 512GBs of memory….. So maximally 128 vCPUs…..
Ken.Cline:
I make this decision based on a couple things:* – How important are the VMs in questions?
* If they’re truly “mission critical”, then I keep the number small – on the order of 10:1
* If they’re “important”, then let’s look at 20:1
* If they’re “who cares if they’re up”, then load ’em up!* – How large is the environment? I like to deploy a minimum of two hosts (three makes me happier)
* 20 systems @ 2 hosts = 10:1, @ 3 hosts = 7:1
* 100 systems @ 2 hosts = I wouldn’t do it, @ 3 hosts = 34:1
* 1,000 systems – now you’re talking! @ 20 hosts = 50:1, @ 30 hosts = 34:1, @ 20 hosts = 50:1, @ 10 hosts = 100:1
* 10,000 systems – you can bet I’m going to have a few hosts with 50 to 60 (or more) VMs and some hosts with 10 (or less) VMs!So, there’s not single “right” answer (other than “it depends”)
As mentioned I think it comes down to a few things.
How powerful is your host as far as resources.
What type of applications?
How many eggs do you want in a basket?
For us we tend to go more on load percentage than a hard number. In our non-production environments we will go higher load percentage. In our production environment we try to keep it fairly low, around 50-60% load. This allows us to have room for resource spikes as well as the ability to lose more hardware.
It all comes down to risk assessment.