Example:
CentOS-VM with 20GB Thin Provisioned Virtual Disk on Nexenta-Hosted NFS-Datastore:
Used Space as seen in vShpere Client: 2,36 GB
Clone of the VM through vCenter Server to another Host+Datastore (direct-attached vmfs-5) -> Used Space: 11,98 GB
(same thing happens with backups being restored)
Cloning back the 11,98 GB VM to the original Host/Datastore -> Used Space: down to the original 2,36 GB
Zeroing free space inside the cloned 11,98 GB VM and running vmkfstools -k (=punchzeros) on the vmdk -> Used Space: down to the original 2,36 GB
Any ideas what's happening here?