What is Virtual Machine Snapshots and Its Best Practices

Spread The Knowledge

In this blog we are going to cover about virtual machine snapshot and their best practices to create and delete the snapshot in VMware vSphere environment.

Virtual machine snapshot is a point-in-time image/copy of the VM. It preserve the state and data of the VM. You can revert snapshot copy to get the virtual machine back in original state when you have taken the snapshot. Generally we take snapshot before patching or doing any critical activity which may affect the VM.

It contains data such as virtual machine state(power on/off), disks files along with configuration files.

Guide On How To Take Snapshot

VMware vSphere provides a nice snapshot manager option from where you can create, manage, and delete the snapshots. Before taking snapshot, make sure that you have enough free space to store the files in your datastore.

Now login to the vSphere web client and search for the virtual machine.

  1. You can either right click on VM or Click on Action button.
Virtual Machine Snapshot
Virtual Machine Snapshot

2. Select Snapshots option from the menu

3. Click on Take Snapshot

4. You will be ask to give a name for the snapshot or leave it to default.

Snapshot Naming
Snapshot Naming

5. You can check the option ‘snapshot the virtual machines memory’ to get the data which is in memory at the time of snapshot creation.

6. Now you can see the snapshot, you have just created.

Snapshot Manager
Snapshot Manager

7. You can also revert and delete the snapshot from here. Please deleting the snapshot make sure you do not need it anymore for the use.

Delete Snapshot
Delete Snapshot

When snapshot is created, below files are created.

  • .vmdk and delta.vmdk – These are child disks created from the original disks file.
  • .vmsd – This is a database of the virtual machine snapshot information. This is the main source of information for the snapshot manager.
  • Snapshot.vmsn – This file includes the current configuration and optionally the active state of the virtual machine. Capturing the memory state of the virtual machine lets you revert to a turned on virtual machine state.

Best practices for using snapshots

You should follow the best practices for using the snapshot in the vSphere environment.

  • You should not use snapshots as a backup. Try to use proper backup tool like Commvault or others.
  • You can take maximum 32 snapshots in a chain but use only 1 or 2 for best practices.
  • You should not use a single snapshot for more than 72 hours. Delete it if not required.
  • When using a third-party backup software such as Commvault, ensure that snapshots are deleted after a successful backup.
  • Snapshots for RDM VMs would not work.

You may also like:

Solution For VMware Virtual Machine Disks Consolidation Is Needed

How To Configure Virtual Machines To Automatically Upgrade VMware Tools

Spread The Knowledge

Leave a Comment