I have a few observations about CSVs in a Hyper-V 2012 cluster:
1. Online/Offline status in Disk Management.
Take a look at the screenshot below. I was troubled by seeing the CSV offline. I thought there was a problem (not really).
Here is how the cluster works:
The CSV shows up as an online disk only on the cluster node which is managing is (or is the owner of that CSV). If you change the owner of that CSV to another node, the CSV disk will go offline on this node. However both nodes can still access the CSV via C:\ClusterStorage\vol2
2. Cannot map a drive to view CSV contents:
You cannot map a drive to C$ and try to view the contents of C:\ClusterStorage\VolX. There will NOT be any error but the contents of that directory will be blank. You can RDC to the hyper-V machine and view the contents of that directory successfully.
3. No drive letter is assigned to a CSV
The moment you add a disk to cluster storage volume, it will lose its drive letter. This is by design (normal). A CSV is supposed to be accessed via its map point under C:\ClusterStorage\VolX. This is noticeable in the screenshot above.