There are four ways to shut down a VM running on Ravello.
The relevant API calls are at:
When initiating the stop API call, the system issues ACPI signals to the VM to stop it gracefully.
The VM is allowed 20 minutes to shut down gracefully, after which it will be forcefully taken down.
When using the Ravello managment UI, or when auto-stopping applications, the Stop API call is currently used behind the scenes.
The system issues continuous ACPI signals to the VM to stop it gracefully, without forcing it to shut down. Make sure the VM has ACPI capabilities when using this call; if it does not, this might result in an endless STOPPING state.
The VM is immediately (and forcefully) powered-off.
4. Shutdown from within the VM
You can always shut down a VM from within the VM. When doing so, Ravello's central management system detects that the VM was shutdown and will change its state to STOPPED.