An error occurred while consolidating disks: msg.fileio.lock.(Can't consolidate VM snapshot)

1.  Tried clicking on consolidate -fail
2.  Tried creating and deleting snapshot -  succeeded, but didn't allow me to consolidate snapshot
3.  Tried creating and snapshot with memory state unticked -- same as above, no-go.
4.  Tried cloning the VM. The clone had consolidated disks, but didn't want the outage of switching VMs, plus the hassle of new mac address on the cloned VM with ghost vNIC issue.

5.  But then tried storage vMotioning the VM.  Bingo!  success!

This originating problem was caused by VADP backup.  Seems vSphere 5.5 handles snapshots differently, or maybe, as I read here.

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UPDATE: 13/11/2014
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overlooked two important facts here:

1) the old snapshots on your old disk are not cleaned up when you sVMotion to a new disk.
2) Trying to delete them from DataStore browser doesn't work.  Are these files still locked?  Shouldn't be as the .vmsd file is empty and the disks referenced as active by the VM is no longer the delta VMDK.  More to come.

I hope this helps someone avoid an outage for their VMs.

KC