Overnight, one of my VMs stopped. vCentre was reporting "No more disc space for virtual disc XXXX.vmdk". The datastore where the VM & VMDKs are stored had over 1TB of free disc space.
Googling only shows answers telling me to free disc space on my datastore which, clearly, isn't needed. All my VMs are thick provisioned.
With the VM powered off, I just moved it to another host (leaving all the files on the same datastore) and it powered up fine.
What is going on here?