VM snapshots usage will be discussed in Chapter 8, Advanced VM and Resource Management, but there are some interesting improvements starting with vSphere 6.0. To perform a snapshot deletion process, the mirror driver (introduced in vSphere 5 to improve storage vMotion) is used, so that the changes to the VM are written to the active VMDK and the base disk during consolidation.

This should not only speed up the consolidation process (in the client this is called a delete snapshot, but formally, is a consolidation), but minimize the infamous stun issue where a VM can temporally freeze. For more information, see http://cormachogan.com/2016/01/06/snapshot-consolidation-changes-in-vsphere-6-0/.

Another improvement on VM snapshot is related to the VVoLs and vSAN use cases (both discussed later), using VVoL snapshots are offloaded to the storage level (usually more efficient in snapshot management), using vSAN a new efficient snapshot model is used.