When you have some VMs with thin provisioned disks, you may have noticed that these will continue to grow, and never shrink, even after cleaning out data from within the VM. Currently, VMware does not have automatic space reclamation, unless you're running a SAN which supports this (and you have the necessary components installed, such as EqualLogic's HIT-kit). Luckily, there are some tools to allow you to reclaim unused space from your virtual thin disks. The only downside is that you have to power off the affected machines.

Reclaiming disk space only works when the blocks on your virtual disk are really empty. Deleting data usually only removes the entries from the file allocati  ...