(1) What's the technical difficulty in shrinking (meaning discarding units in the filesystem filled with zeros) VM's that have a snapshot involved? I'd like to understand, and perhaps even work on a third party app for this, since the VMDK spec is open source, and there's libvmdk.
(2) VirtualBox handles this. Both on snapshots with descendants and leafs. Is it coming in VMware?
(3) How does "VM->Manage->Clean Up Disks" differ from "vmware-vdiskmanager -k"? For Linux guests, the former always tells me "Cleanup is not necessary", where the latter always runs.