How To Convert Thick Virtual Disks to Thin in VMWare ESX / ESXi
To convert a thick format disk to a thin format disk, clone the virtual disk with the destination disk type set to thin.
To clone a disk and convert it to thin format, run this command from the Service Console or from the VMware Command-Line Interface:
vmkfstools -i -d thin
For example:
vmkfstools -i vDiskName.vmdk -d thin vDiskNameThin.vmdk
If you are using VMWare RCLI application use :
vmkfstools.pl --server 192.168.xxx.xxx -i /vmfs/volumes/datastore1/VMSRV0004-VM1/VMSRV0004-VM1.vmdk -d thin /vmfs/volumes/datastore1/VMSRV0004-VM1/VMSRV0004-VM1-thin.vmdk
Note: Dont forget to go back to ESX server and remove the old .vmdk and -flat.vmdk files once you are sure that your VM is operating normally off the thin disk.
