VMware best practices for virtual machine snapshots
I will start this post off with the standard snapshot warning. Just a reminder that Snapshots are not backups, they are only a change log of the original virtual disk. You should not count on them as a backup. There are a number of different reasons that you might use a snapshot for. One of my most used reasons would be for a software upgrade I would use the snapshot to allow for an easy rollback to the machine state prior to the upgrade. If you have some other reasons leave a comment to share with others.
- The maximum supported amount in a chain is 32. However, VMware recommends that you use only 2-3 snapshots in a chain.
- Use no single snapshot for more than 24-72 hours.
- This prevents snapshots from growing so large as to cause issues when deleting/committing them to the original virtual machine disks. Take the snapshot, make the changes to the virtual machine, and delete/commit the snapshot as soon as you have verified the proper working state of the virtual machine.
- Be especially diligent with snapshot use on high-transaction virtual machines such as email and database servers. These snapshots can very quickly grow in size, filling datastore space. Commit snapshots on these virtual machines as soon as you have verified the proper working state of the process you are testing.|
- If using a third party product that takes advantage of snapshots (such as virtual machine backup software), regularly monitor systems configured for backups to ensure that no snapshots remain active for extensive periods of time.
- Snapshots should only be present for the duration of the backup process.
- Snapshots taken by third party software (called via API) may not show up in the vCenter Snapshot Manager. Routinely check for snapshots via the command-line.
- An excessive number of snapshots in a chain or snapshots large in size may cause decreased virtual machine and host performance.
You can find some more details from VMware on troubleshooting snapshots here.
About Brian Suhr
Brian is a VCDX5-DCV and a Sr. Tech Marketing Engineer at Nutanix and owner of this website. He is active in the VMware community and helps lead the Chicago VMUG group. Specializing in VDI and Cloud project designs. Awarded VMware vExpert status 6 years for 2016 - 2011. VCP3, VCP5, VCP5-Iaas, VCP-Cloud, VCAP-DTD, VCAP5-DCD, VCAP5-DCA, VCA-DT, VCP5-DT, Cisco UCS Design