Introduction
Snapshots are one of the best features in vSphere. Snapshots are the safety net built into the platform that allows you to easily revert to a previous known good state in the event that something happens in a VM. Some environments run regularly scheduled snapshots. Some administrators use them only before changes are made in the environment.
Over a period of time, virtual machine snapshots grow to a point that they can exhaust all of the available disk space on a datastore. Administrators can take multiple snapshots and each snapshot references a parent, which means that there is added overhead for IO since the system has to combine multiple files in order to find the correct data to return. The extra latency is minimal and the benefits of the snapshot far outweigh the time.
Snapshots do, however, introduce a management point, since you should not let snapshots linger for too long for fear of exhausting disk space. PowerCLI is an easy way to script and maintain your snapshots...