6.7

A snapshot preserves the following information:
n
Virtual machine settings. The virtual machine directory, which includes the disks added or changed
after you take the snapshot.
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Power state. The virtual machine can be powered on, powered off, or suspended.
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Disk state. State of all the virtual machine's virtual disks.
n
(Optional) Memory state. The contents of the virtual machine's memory.
The Snapshot Hierarchy
The vSphere Client presents the snapshot hierarchy as a tree with one or more branches. Snapshots in
the hierarchy have parent to child relationships. In linear processes, each snapshot has one parent
snapshot and one child snapshot, except for the last snapshot, which has no child snapshot. Each parent
snapshot can have more than one child. You can revert to the current parent snapshot or restore any
parent or child snapshot in the snapshot tree and create more snapshots from that snapshot. Each time
you restore a snapshot and take another snapshot, a branch (child snapshot) is created.
Parent Snapshots The first virtual machine snapshot that you create is the base parent
snapshot. The parent snapshot is the most recently saved version of the
current state of the virtual machine. Taking a snapshot creates a delta disk
file for each disk attached to the virtual machine and optionally, a memory
file. The delta disk files and memory file are stored with the base .vmdk file.
The parent snapshot is always the snapshot that appears immediately
above the You are here icon in the Snapshot Manager. If you revert or
restore a snapshot, that snapshot becomes the parent of the You are here
current state.
Note The parent snapshot is not always the snapshot that you took most
recently.
Child Snapshots A snapshot of a virtual machine taken after the parent snapshot. Each child
snapshot contains delta files for each attached virtual disk, and optionally a
memory file that points from the present state of the virtual disk (You are
here). Each child snapshot's delta files merge with each previous child
snapshot until reaching the parent disks. A child disk can later be a parent
disk for future child disks.
The relationship of parent and child snapshots can change if you have multiple branches in the snapshot
tree. A parent snapshot can have more than one child. Many snapshots have no children.
Caution Do not manually manipulate individual child disks or any of the snapshot configuration files
because doing so can compromise the snapshot tree and result in data loss. This restriction includes disk
resizing and making modifications to the base parent disk by using vmkfstools.
vSphere Virtual Machine Administration
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