SQL - ESXi v Hyper-V
At the moment I have an ESXi box running 6 VMs.
After looking at our current servers I have identified at least 4 that will need to be upgraded to 2008 R2. My only issue, of course, is the cost of licenses. The LA charge £66 each for a Standard license and £185+ for Enterprise. The way I look at it is that it makes sense for me to purchase the Enterprise license so that I can run 4 VMs using Hyper-V without any additional costs.
Obviously sticking with ESXi I would need to buy four times the licenses which would cost £264 (Standard).
I just wanted your thoughts whether
A) Hyper-V is stable and strong as VMware
B) Would you stick with ESXi because it's something you've been using from the beginning
C) Stick with ESXi for consistency
D) Which would be better at performance for running SQL
The Microsoft Lics for Server 2k8 R2 when running in VMs are fine reguardless of which hypervisior you use (Hyper-V or ESXi)
More here - Microsoft Volume Licensing - Microsoft Licensing for Virtualization
ESXi footprint is lower on resources, so in that sense you'd get more bang for your buck... I don't think Hyper-V is the best route for performance but as it's on the server and ready to go - it's a bit easier, that said vSphere is really very simple to use.
You've also got the option of Citrix XenServer. I use it here and am very happy with it.