Thin to thick (easy :-): within the vSphre client open datastore browser and right click on vmdk file you want to convert to think and select Inflate.
Thick to thin (a little bit "pro")
- Connect to host via SSH and use the below syntax:
1. Shutdown the VM so that we can get exlusive access to the virtual disk.
2. Log into your ESX host using SSH and cd into the VM directory that contains your virtual disk.
3. Run vmkfstools –i srcDisk -d thin dstDisk
4. Edit the settings of VM and remove the existing drive srcDisk. Add a new hard drive and choose the existing drive option then browse to your new thin dstDisk
5. Boot the VM and enjoy.
Note: Dont forget to go back to ESXi host remove the old .vmdk
and -flat.vmdk files once you are sure that your VM is operating
normally off the thin disk.
