Good morning everyone!
I have two questions about what to do with my exchange 2010 storage:
1. should the disks housing the exchange databses be local to the actual exchange VM or mapped out to a LUN on our Netapp?
2. if local disk is way to go, should it be thin or thick provisioning?
The answer for both is: it depends 🙂
If you will use local disk for Exchange VM, this VM will have limited mobility between hosts in your ESXi cluster and availability will be affected too... because of this (thinking in availability and mobility) I will recommend you put your disk in a shared storage.
About thin and thick disk, actually there is no much performance different between this two type of disks... anyway if you choose thin, there is a administrative overhead to manage the disk grow.
I echo the above statement. It entirely depends on how you want to go about it.
Whatever you decide make sure that the underlying data store is adequately spec'd for your businesses technical requirements when it comes to Exchange performance. I think Eager Zero Thick disks are recommended as best practice. Take a look at these articles:
VMware KB: Microsoft Clustering on VMware vSphere: Guidelines for supported configurations