Sometimes someone forgets to unmount the CD drive of a VM. This will interfere with operation tasks like setting a host in maintenance mode or using Update Manager.

I recently had this issue, and the “update manager compliance check” told me that several VM’s where connected to a CD drive, which may interrupt the update process. I quickly found my favorite tool for vcenter management, the powerCLI. The quick and dirty oneliner ended up like this:

get-cluster %clustername% | get-vm | where {(($_ | Get-CDDrive).isopath) -gt ""} | %{$_ | Get-CDDrive | Set-CDDrive -NoMedia -Confirm:$false}

Replace %clustername% with your cluster name, and all your troubles will be over 🙂

I have always loved oneliners. I have spent the part time of my time working in bash terminals, where the history has always been persistent. Luckily Microsoft has also seen the light, and history is now persistent (and searchable) in powershell. Search for a phrase using ctrl+r, search further back by pressing ctrl+r again. I’m sure you will learn to love it, if you don’t already do.