The user asked how to display all "unmounted" disk devices. (
Well, volumes..).
In the end, I think parsing the dmesg output may be the only option... poor FreeBSD users.
EDIT: Strange, browsing the FreeBSD CVS I found that HW_DISKNAMES is defined in
sysctl.h? It's not documented in the man page though... can anyone check and see if the above works?