Once upon a time… Nah… This is not a fairy tale so lets do it differently.
What is the maximum size of a virtual disk that vSphere 5.1 supports? If you have no idea, then probably you have not passed your VCP (because they ask those silly kind of questions) but you can use Eric Siebert's page VMware configuration maximums from 1.0 to 5.1 if you need a reminder.. 2TB
And how much does Hyper-V support? Much more.. 64TB.
And GCE? Well they have whopping 10TB persistent disk!
How many hosts in a does a single vCenter support? 1,000
And how many hosts per cluster? 32
And Powered on VM's? 10,000
And how many simultaneous vMotions?
But Hyper-V supports 64 nodes in a cluster and 8,000 VM's (if they are powered on or not I do not know..) and so many simultaneous Live Migrations..
(These numbers are valid for current versions, but I am sure that in future releases they will go up higher)
Who …. #@##@ Cares?????? (and therefore the reason for this post…)
It does not matter if you can run 10,000 VM's or 8,000..
It is wonderful that you can store 10TB of data on a single persistent disk on GCE. (Heaven forbid that you actually have to replicate that amount of data somewhere else, back it up or even worse have to restore it!!)
And why not - because in approximately 80% of the deployments in the world (most probably more) - you will never get anywhere close to those numbers. You really won't!
So what is important then? And what should you really look for?
I would say is the solution which is suitable for you. Don't base your decisions on one parameter out of several hundred that most of you will never come across anyway.
Yes there are the certain edge cases that the sheer scale of some environments will exceed one maximum or the other. But I can assure you that when you hit 32 nodes in a single cluster I promise you, the fact that Hyper-V can support 64 is the last reason you should migrate your environment over.
If you are already going over 8,000 VM's in your Hyper-V environment then the fact that vCenter can support 10,000 should not be the reason to switch.
The technology that is suited for you, the technology that will allow your to fulfill your requirements, stand up to your SLA's, the one that suits your needs, the one that fits into your business practices and models, and that will be the most cost effective for you…
That is the solution you should choose.
(I shiver once more having to think about backing up / replicating a 10TB volume… Restoring that - don't even want to go there….)
Comments and thoughts of course are always welcome…