Index: libexec/rc/rc.d/dumpon
===================================================================
--- libexec/rc/rc.d/dumpon
+++ libexec/rc/rc.d/dumpon
@@ -13,6 +13,9 @@
 desc="Dump kernel corefiles from swap to disk"
 start_cmd="dumpon_start"
 stop_cmd="dumpon_stop"
+extra_commands="startzvol stopzvol"
+startzvol_cmd="dumpon_startzvol"
+stopzvol_cmd="dumpon_stopzvol"
 
 dumpon_try()
 {
@@ -39,7 +42,7 @@
 	# early so a crash early in the boot process can be caught.
 	#
 	case ${dumpdev} in
-	[Nn][Oo] | '')
+	[Nn][Oo] | '' | /dev/zvol/*)
 		;;
 	[Aa][Uu][Tt][Oo])
 		dev=$(/bin/kenv -q dumpdev)
@@ -61,10 +64,34 @@
 	esac
 }
 
+dumpon_startzvol()
+{
+	# Enable dumpdev on zvol
+	case ${dumpdev} in
+	/dev/zvol/*)
+		dumpon_try "${dumpdev}"
+		;;
+	*)
+		;;
+	esac
+}
+
+dumpon_stopzvol()
+{
+	case ${dumpdev} in
+	/dev/zvol/*)
+		rm -f /dev/dumpdev
+		/sbin/dumpon -v off
+		;;
+	*)
+		;;
+	esac
+}
+
 dumpon_stop()
 {
 	case ${dumpdev} in
-	[Nn][Oo] | '')
+	[Nn][Oo] | '' | /dev/zvol/*)
 		;;
 	*)
 		rm -f /dev/dumpdev
Index: libexec/rc/rc.d/zpool
===================================================================
--- libexec/rc/rc.d/zpool
+++ libexec/rc/rc.d/zpool
@@ -4,7 +4,7 @@
 #
 
 # PROVIDE: zpool
-# REQUIRE: hostid
+# REQUIRE: hostid disks
 # BEFORE: zvol mountcritlocal
 # KEYWORD: nojail
 
Index: libexec/rc/rc.d/zvol
===================================================================
--- libexec/rc/rc.d/zvol
+++ libexec/rc/rc.d/zvol
@@ -5,7 +5,6 @@
 
 # PROVIDE: zvol
 # REQUIRE: zpool
-# BEFORE: dumpon
 # KEYWORD: nojail
 
 . /etc/rc.subr
@@ -19,6 +18,9 @@
 
 zvol_start()
 {
+	if [ -x /etc/rc.d/dumpon ] ; then
+		/etc/rc.d/dumpon startzvol
+	fi
 	# Enable swap on ZVOLs with property org.freebsd:swap=on.
 	zfs list -H -o org.freebsd:swap,name -t volume |
 	while read state name; do
@@ -41,6 +43,9 @@
 			;;
 		esac
 	done
+	if [ -x /etc/rc.d/dumpon ] ; then
+		/etc/rc.d/dumpon stopzvol
+	fi
 }
 
 load_rc_config $name