Entire hierarchies of checkpoints can be created, and each checkpoint can be custom
named, making it easy to understand what each checkpoint represents. Checkpoints
can then be applied to a virtual machine. Applying a checkpoint reverts a virtual
machine back to the state that it was in when the checkpoint was created.
CHECKPOINTS WITH FIXED VIRTUAL HARD DISKS
A fixed virtual hard disk preallocates all space at creation time, but if a checkpoint
is created, a differencing virtual hard disk is created for future writes. This means
that a dynamic virtual hard disk is being used for writes and will therefore
consume additional space that may not have been originally planned. There is
also a small performance penalty as the dynamic differencing disk grows.
To create a checkpoint using Hyper-V Manager, select the virtual machine and select
the Checkpoint action. This can be performed on a running virtual machine or on one
that’s shut down. For a running virtual machine, the creation may take a few seconds,
because the contents of the memory and configuration state must be saved. By
default, the checkpoint will be named
6.6, which shows a virtual machine with two checkpoints. They can be renamed
simply by selecting and choosing the Rename action. Renaming the checkpoints is
useful, so you’ll understand at a later time what the state of the virtual machine was at
the point of checkpoint. Renaming can also be performed using PowerShell with the
Rename-VMSnapshot cmdlet and specifying the existing checkpoint name and the new
name via the Name and NewName attributes. For example:
Figure 6.6 A VM with two checkpoints
Rename-VMSnapshot -VMName savdalsr02 -Name "savdalsr02—(5/30/2016—11:16:25 AM)"
-NewName "Pre-Patch 5/30/2016"
Checkpoints can be deleted via the Delete Checkpoint action, and an entire subtree of
multiple parent-child checkpoints can be deleted via the Delete Checkpoint Subtree