Hi
I've got a customer whos vSphere environment I want to upgrade to version 5.1. The hosts are currently running ESXi 4.1 and have two datastores attached. These are both on VMFS Version 3.31.
Now I have had a similar case where an upgraded 5.0 host wouldn't recognize a datastore with VMFS Version 3.21. Apparently datastores created on ESX 3.0.0 hosts are not supported on ESXi 5.x hosts.
Now my question: What is the lowest VMFS Version that an ESXi 5.x (5.1.0 UP1 in my case) will recognize / support? Im googled a while and haven't found any info directly from VMware. All I found was a blog article where the author mentioned that 3.31 onward is compatible. (Cosonok's IT Blog: Notes on Migrating from Compaq MSA1000 to VMware vSphere 5). Can anybody acknowledge this statement? Is 3.31 the lowest supported VMFS Version a ESXi 5.x host can work with?
Thanks alot 
David