Now I mentioned I wanted to spend most of our time together on
this lesson covering Hyper‑V VM checkpoints.
This is a commonly misunderstood concept,
so I want to make sure we get it right.
Checkpoints allow us to save and restore a Hyper‑V VM
state at a particular point in time.
So, for example,
you might want to take a checkpoint before applying Windows
updates or before making a configuration change.
You should note that checkpoints are not a replacement for VM
backups. You absolutely, of course, should be regularly
backing up your VMs, but checkpoints,
although some administrators will use them as VM backups, that's not the intent.
Instead, the intent of checkpoints is to provide,
as I mentioned,
a rollback method to roll back if you have a config
change or an update that's bad.
There's two types of checkpoints available in Hyper‑V. The
standard checkpoint is an application‑consistent snapshot of
the VM and its in‑memory state.
So if you apply a standard checkpoint,
you're going to see the VM state not only in terms of
the file system and applications,
but any open processes. Anything that's in memory will be restored.
The production checkpoint uses the Volume Shadow Copy Service to make
data‑consistent snapshots that don't include the memory state.
So an obvious question is when would you as a hybrid cloud administrator
choose the standard checkpoint versus the production? Well, Microsoft
recommends that you use production as your default.
Now the production is going to ensure that all the data on
the VHD is captured, and any databases, if it's an Active
Directory domain controller,
the state of Active Directory, all of those file states will be backed
up, but, of course, you lose any in‑memory data.
Standard checkpoints are intended for active test and
development purposes where you need to, for instance,
redo a test with a particular memory state with a file open,
with a database open. Production checkpoints kind of sort of
can be used as a backup, but, again, according to Microsoft,
we want to be clear that checkpoints are not intended
as a replacement for VM backups.
Now you can do a number of things with these
checkpoints. I mentioned the term apply.
That's where you restore a VM state using a saved checkpoint. You can
have Hyper‑V automatically create checkpoints whenever you stop a VM.
We can rename and organize checkpoints, of course, we can delete
them, and we can export them.
You might want to build a new virtual machine based on a saved
checkpoint, and in that case, I would want to do a production
checkpoint because I don't want the memory state. I just want a data‑consistent VSS‑based snapshot of the VM's file system.