View the extension's status

The extension's status can be found by running the PowerShell cmdlet:

Get-AzVM -ResourceGroupName $RGName -Name $vmName -Status

or the CLI command:

az vm extension show -g <RG Name> --vm-name <VM Name>  --name <Extension Name>

or in the Azure portal, by browsing to the VM Blade / Settings / Extensions. You can then click on the extension and check its status and message.