--- etc/rc.d/mdconfig	(revision 229307)
+++ etc/rc.d/mdconfig	(working copy)
@@ -174,10 +174,11 @@ 
 }
 
 _mdconfig_cmd="$1"
+eval _mdconfig_list=\$mdconfig_units
 if [ $# -gt 0 ]; then
         shift
 fi
-[ -n "$*" ] && _mdconfig_list="$*"
+[ -z "$_mdconfig_list" -a -n "$*" ] && _mdconfig_list="$*"
 
 load_rc_config $name
 
--- etc/rc.d/mdconfig2	(revision 229307)
+++ etc/rc.d/mdconfig2	(working copy)
@@ -204,10 +204,11 @@ 
 }
 
 _mdconfig2_cmd="$1"
+eval _mdconfig2_list=\$mdconfig_units
 if [ $# -gt 0 ]; then
         shift
 fi
-[ -n "$*" ] && _mdconfig2_list="$*"
+[ -z "$_mdconfig2_list" -a -n "$*" ] && _mdconfig2_list="$*"
 
 load_rc_config $name
 
--- share/man/man5/rc.conf.5	(revision 229307)
+++ share/man/man5/rc.conf.5	(working copy)
@@ -4203,6 +4203,23 @@ 
 which causes log files flagged with a
 .Cm C
 to be created.
+.It Va mdconfig_units
+.Pq Vt str
+A list of one or more
+.Xr md 4
+units to configure with
+.Xr mdconfig 8
+and
+.Xr newfs 8
+in time to be mounted with
+.Xr fstab 5 .
+If unspecified, the
+.Va mdconfig_md Ns Aq Ar X
+variables are evaluated in consecutive order from md0, until one variable is
+unset or null.
+See the
+.Va mdconfig_md Ns Aq Ar X
+variable descriptions below for more details.
 .It Va mdconfig_md Ns Aq Ar X
 .Pq Vt str
 Arguments to
@@ -4221,10 +4238,12 @@ 
 .Fl f Ar file
 for vnode backed
 .Xr md 4
-devices.
-Note that
+devices. Each
 .Va mdconfig_md Ns Aq Ar X
-variables are evaluated until one variable is unset or null.
+entry listed in
+.Va mdconfig_units
+must be defined in
+.Xr fstab 5 .
 .It Va mdconfig_md Ns Ao Ar X Ac Ns Va _newfs
 .Pq Vt str
 Optional arguments passed to