diff --git a/etc/mtree/BSD.include.dist b/etc/mtree/BSD.include.dist
index df44c229f80a..f2f8556f5785 100644
--- a/etc/mtree/BSD.include.dist
+++ b/etc/mtree/BSD.include.dist
@@ -88,6 +88,8 @@
         ..
         label
         ..
+        mirror
+        ..
         nop
         ..
         stripe
diff --git a/include/Makefile b/include/Makefile
index 4e0470edc9d0..3d34047238e4 100644
--- a/include/Makefile
+++ b/include/Makefile
@@ -36,7 +36,7 @@ LSUBDIRS=	cam/scsi dev/an dev/bktr dev/firewire dev/ic dev/iicbus \
 	dev/ofw dev/ppbus dev/smbus dev/usb dev/wi dev/utopia fs/devfs \
 	fs/fdescfs fs/fifofs fs/msdosfs fs/ntfs fs/nullfs fs/nwfs fs/portalfs \
 	fs/procfs fs/smbfs fs/udf fs/umapfs fs/unionfs \
-	geom/concat geom/gate geom/label geom/nop geom/stripe \
+	geom/concat geom/gate geom/label geom/mirror geom/nop geom/stripe \
 	isofs/cd9660 netatm/ipatm netatm/sigpvc netatm/spans netatm/uni \
 	netgraph/atm security/mac_biba security/mac_bsdextended \
 	security/mac_lomac security/mac_mls security/mac_partition \
diff --git a/sbin/geom/class/Makefile b/sbin/geom/class/Makefile
index 704466159ba1..888233e5f860 100644
--- a/sbin/geom/class/Makefile
+++ b/sbin/geom/class/Makefile
@@ -2,6 +2,7 @@
 
 SUBDIR=	concat
 SUBDIR+=label
+SUBDIR+=mirror
 SUBDIR+=nop
 SUBDIR+=stripe
 
diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index 0f37fccec7ab..40d23b4047eb 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -127,6 +127,7 @@ options 	GEOM_GATE		# Userland services.
 options 	GEOM_GPT		# GPT partitioning
 options 	GEOM_LABEL		# Providers labelization.
 options 	GEOM_MBR		# DOS/MBR partitioning
+options 	GEOM_MIRROR		# Disk mirroring.
 options 	GEOM_NOP		# Test class.
 options 	GEOM_PC98		# NEC PC9800 partitioning
 options 	GEOM_STRIPE		# Disk striping.
diff --git a/sys/conf/files b/sys/conf/files
index 594d4407cbf5..ab5ff567bf76 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -944,6 +944,8 @@ geom/label/g_label.c	optional geom_label
 geom/label/g_label_iso9660.c	optional geom_label
 geom/label/g_label_msdosfs.c	optional geom_label
 geom/label/g_label_ufs.c	optional geom_label
+geom/mirror/g_mirror.c		optional geom_mirror
+geom/mirror/g_mirror_ctl.c	optional geom_mirror
 geom/nop/g_nop.c	optional geom_nop
 geom/stripe/g_stripe.c	optional geom_stripe
 geom/geom_aes.c		optional geom_aes
diff --git a/sys/conf/options b/sys/conf/options
index fdc66b6f70cc..ef150236e613 100644
--- a/sys/conf/options
+++ b/sys/conf/options
@@ -77,6 +77,7 @@ GEOM_GATE	opt_geom.h
 GEOM_GPT	opt_geom.h
 GEOM_LABEL	opt_geom.h
 GEOM_MBR	opt_geom.h
+GEOM_MIRROR	opt_geom.h
 GEOM_NOP	opt_geom.h
 GEOM_PC98	opt_geom.h
 GEOM_STRIPE	opt_geom.h
diff --git a/sys/modules/geom/Makefile b/sys/modules/geom/Makefile
index 880c082902c1..b9757298ab94 100644
--- a/sys/modules/geom/Makefile
+++ b/sys/modules/geom/Makefile
@@ -10,6 +10,7 @@ SUBDIR=	geom_apple \
 	geom_gpt \
 	geom_label \
 	geom_mbr \
+	geom_mirror \
 	geom_nop \
 	geom_pc98 \
 	geom_stripe \