You have probably noticed by now that there is no in-place upgrade path to Windows Server 2012 R2 Essentials. That means fresh build time, which I've just completed in my home lab. As I've been doing since Windows Home Server, it's not all bad, since you can keep most of your data and shares. See also Microsoft's Move settings and data to the Destination Server for Windows Server 2012 R2 Essentials migration.
More good news. If you are stuck with some virtual drives from your pre-ESXi 5.5 VMs that had the 2TB drive size limitation, it's quite straight-forward to resolve this situation, without any down-time. How? Here's the basic steps:
- use vSphere Web Client to edit the properties of the VM and add a new drive, up to 62TB in size
see also Wow, is that a 62TB drive in my home lab?
- in the WS2012R2E VM, use Win+X and choose 'Disk Management' to initialize then format this new drive
- in the WS2012R2E VM's Dashboard, use the STORAGE 'Server Folders' tab and right-click on the data that's on the <2TB drive you wish to evacuate, select 'Move the folder' to the new drive you just formatted
- once it's completed with the move, be sure there's no data on the old <2TB drive, then use vSphere Web Client to edit the properties of the VM and delete that drive
That's it! It may be even clearer if you see the process, and hear me describe it, in the video below.