[SOLVED] Snapshot from command line / shell

Maybe qm snapshot does what you want. Have a look at the manpage:

Code:
       qm snapshot <vmid> <snapname> [OPTIONS]

        Snapshot a VM.

        <vmid>: <integer> (1 - N)
            The (unique) ID of the VM.

        <snapname>: <string>
            The name of the snapshot.

        --description <string>
            A textual description or comment.

        --vmstate <boolean>
            Save the vmstate