ships a simple heartbeat service. Once the Guest Additions are active, the guest sends frequent heartbeat pings to the host. If the guest stops sending the heartbeat pings without properly terminating the service, the VM process will log this event in the VBox.log file. In the future it might be possible to configure dedicated actions but for now there is only a warning in the log file.

There are two parameters to configure. The heartbeat interval defines the time between two heartbeat pings. The default value is 2 seconds, that is, the heartbeat service of the Guest Additions will send a heartbeat ping every two seconds. The value in nanoseconds can be configured like this:

VBoxManage setextradata VM-name \
VBoxInternal/Devices/VMMDev/0/Config/HeartbeatInterval 2000000000

The heartbeat timeout defines the time the host waits starting from the last heartbeat ping before it defines the guest as unresponsive. The default value is 2 times the heartbeat interval (4 seconds) and can be configured as following, in nanoseconds:

VBoxManage setextradata VM-name \
VBoxInternal/Devices/VMMDev/0/Config/HeartbeatTimeout 4000000000

If the heartbeat timeout expires, there will be a log message like VMMDev: HeartBeatCheckTimer: Guest seems to be unresponsive. Last heartbeat received 5 seconds ago. If another heartbeat ping arrives after this warning, there will be a log message like VMMDev: GuestHeartBeat: Guest is alive.