Howto Shrink a Thin Provisioned Virtual Disk (VMDK)

Shrink VMDK File

1. Power off the Virtual Machine, or disconnect the virtual Disk you want to shrink
2. Connect to the ESXi Host with SSH
3. Navigate to the Virtual Machine Folder
4. Verify disk usage with du
5. Run vmkfstools -K [disk]
6. Verify disk usage with du

root@esx3:/vmfs/volumes/ds1/vma $ du -h vma_1-flat.vmdk
7.9G vma_1-flat.vmdk

root@esx3:/vmfs/volumes/ds1/vma $ vmkfstools -K vma_1.vmdk
vmfsDisk: 1, rdmDisk: 0, blockSize: 1048576
Hole Punching: 25% done.

root@esx3:/vmfs/volumes/ds1/vma $ du -h vma_1-flat.vmdk
1.9G vma_1-flat.vmdk