Hi Craig,

I am working with Sean Bruno to set up some BHyve VM's.

 Great !

If I want to have the VM's start via an rc.d script, and
have the VM be headless, what is the best way to have
the VM console still be accessible?

Has anyone done something like use netcat
to direct the BHyve stdio to a socket?
That way the serial console could be accessed remotely
via telnet or ssh.

Is there a better way to do this?

One way is to use the cloneable null-modem driver, nmdm(4). Others have used tmux for this, but I'll give a quick overview of the former.

kldload nmdm.ko before starting VMs, e.g. at boottime or in rc.conf's kld_list variable.

Use the '-c' option for bhyveload to point it at one end of an nmdm instance, and use it in place of "stdio" in the bhyve commandline.

 bhyveload .... -c /dev/nmdm0A ...
 bhyve  ... -l com1,/dev/nmdm0A ...

You can then attach to the other end (nmdm*B) with any tool of your choice - cu, screen, or socat to relay the device to a network connection. Some experimentation may be required :)


freebsd-virtualization@freebsd.org mailing list
To unsubscribe, send any mail to 

Reply via email to