This diff explains a little more about the send commands. send pauses the VM and send its memory + the start parameters.
It's not obvious when you don't know vmctl. Index: vmctl.8 =================================================================== RCS file: /cvs/src/usr.sbin/vmctl/vmctl.8,v retrieving revision 1.47 diff -u -p -r1.47 vmctl.8 --- vmctl.8 11 Sep 2018 04:03:16 -0000 1.47 +++ vmctl.8 19 Sep 2018 08:14:11 -0000 @@ -89,7 +89,9 @@ Reset and terminate all VMs. .It Cm send Ar id Send a VM with the specified .Ar id -to standard output and terminate it. +to standard output and terminate it. The VM is paused while sending. +Data sent to standard output contains the VM parameters and its memory, +it does not contain the disk image. .It Cm show Op Ar id An alias for the .Cm status This diff adds an explanation about moving a VM from one host to another. Not sure if it should be in the man page. Index: vmctl.8 =================================================================== RCS file: /cvs/src/usr.sbin/vmctl/vmctl.8,v retrieving revision 1.47 diff -u -p -r1.47 vmctl.8 --- vmctl.8 11 Sep 2018 04:03:16 -0000 1.47 +++ vmctl.8 19 Sep 2018 08:17:16 -0000 @@ -89,7 +89,12 @@ Reset and terminate all VMs. .It Cm send Ar id Send a VM with the specified .Ar id -to standard output and terminate it. +to standard output and terminate it. The VM is paused while sending. +Data sent to standard output contains the VM parameters and its memory, +it does not contain the disk image. +.Pp +In order to move a VM from one host to another, disk files must be +synced between the send and the receive processes and must have the same path. .It Cm show Op Ar id An alias for the .Cm status
