I recently wanted to return a list of snapshots which were older than 3 days within my environment, this was primarily to return any snapshots that had been created by third party applications that take advantage of snapshots. This would prevent no single snapshot from growing to be large in size, which may impact on VM performance.
I compiled a powershell script leveraging vSphere PowerCLI to capture the snapshots that were older than a particular number of days, in my case and for the below example I will be using 3 days as mentioned above.
Firstly, I would need to register the PowerCLI snap-ins to the current powershell session and then connect to the vCenter server (in this example, the vCenter server is named SERVER1);
# Adds registered vSphere PowerCLI snap-ins to the current session
Add-PSsnapin VMware.VimAutomation.Core >$null
# Connect to the vCenter Server
Connect-VIServer SERVER1 >$null # Enter the name of your vCenter server
Once I have established a connection to the vCenter server, I will retrieve all virtual machines and then pipe the results to the Get-Snapshot cmdlet. As I do not require to return all snapshots that have been created only those that are older than 3 days, I will be required to filter the results based on the Created attribute of the snapshot. This is achieved by using the subtract method to the DateTime object.
Finally, I wanted to only return a number of attributes such as the VM name (VM), Snapshot Name (Name), Snapshot Created Timestamp (Created) and Snapshot size (SizeMB) so these objects will be selected for the output
# Retrieve VM snapshots older than 3 days
Get-VM | Get-Snapshot | Where {$_.Created -lt (Get-Date).AddDays(-3)} | Select-Object VM, Name, Created, SizeMB
Alternatively, it is possible to create alarms within vCenter to alert when a virtual machine snapshot is a certain size; this following article details these steps:
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