Hi Nick,
you have a case of a "hidden" snapshot.
Some point in time you had snapshots on that machine, be it after a backup program or a manual snapshot creation.
This happens when snapshots is the process of being deleted, it fails, but the Snapshot manager clear its list.
Both machines have at least 150 GB of snapshots.
The files named -0000001.vmdk are snapshots.
You will need to consolidate the snapshot, and as you are running vSphere 5.0 you can select consolidate from the same drop down menu as the Snapshot Manager is selected.
Other ways to consolidate snapshots:
1. First try creating a snapshot, then deleteing it by selecting "Delete all". Sometimes that works and it removes the "hidden" snapshot as well. Note that you have at least 100 GB of snapshots and it could take a lot of time to delete. If you lose connection to the ESXi host in the prpcess try restarting the MGMT agents (see method below).
2. Try turning off the VM, create a snapshot, and then select Delete all. This will at least make sure that the delta file while you are deleting the snapshot, doesn't get bigger.
3. If this doesn't work you should try to move the VM to a empty datastore and try to remove it again with "Delete all".
4. You can also clone the VM to another datastore. That will always consolidate snapshots.
Here is the kb how to delete snapshots in the ESX console. Please make sure to try the other procedures before using this method.
Heres a way to determine if a VM has snapshot.
And if your ESXi hosts lose the connection to the vCenter it could help to restart the Management agents.
vmice.net
