Well, the machine-id of that Debian VM was ... 38d05397c25548b4f4bda7751b5062 ... and ... $ FOO=`cat /dev/urandom | tr -dc a-z0-9 | head -c${1:-30}`

Well, the machine-id of that Debian VM was ... 38d05397c25548b4f4bda7751b5062 ... and ... $ FOO=`cat /dev/urandom | tr -dc a-z0-9 | head -c${1:-30}` $ echo $FOO 6we4gvnmx00w208ffty6i11m82rw6d But I have no clue whether systemd would be happy with that. Maybe later I can test more. Edit: Oops. Make that ... $ FOO=`cat /dev/urandom | tr -dc abcdef0-9 | head -c${1:-30}` $ echo $FOO b486935dbb9e9fe603328a19e2b5b4