Checking the creation time of an Azure IaaS VM

I recently had a requirement to check the age of VMs deployed in Azure. As I looked it became clear there was no metadata for a VM that shows its creation time. When you think about this it may be logical since if you deprovision a VM (and therefore stop paying for it) then provision it again what is its creation date? When it was first created or when it last was provisioned.

As I dug in there is a log written at VM creation however by default these are only stored for 90 days (unless sent to Log Analytics) BUT if its within 90 days I could find the creation date of any VM. For example:

What if the VM was not created in the last 90 days? If the VM uses a managed disk you can check the creation date of the managed disk. If it is NOT using a managed disk then there is not creation time on a page blob however by default VHDs include the creation data and time as part of the file name. Therefore to try and find the creation data of a VM I use a combination of all 3 by first looking for logs for the VM, then look for a managed disk and finally try a data in unmanaged OS disk.

 

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