Convert Virtual Disk from Thin to Thick
Here is the way to Convert Virtual Disk from Thin to Thick
If you created a virtual disk in the thin format, you can convert it to thick.
The thin provisioned disk starts small and at first, uses just as much storage space as it needs for its initial operations. After having been converted, the virtual disk grows to its full capacity and occupies the entire datastore space provisioned to it during the disk’s creation.