diff --git a/sbin/mdconfig/mdconfig.8 b/sbin/mdconfig/mdconfig.8
index 6ed7e8afd41b..9226fbef1992 100644
--- a/sbin/mdconfig/mdconfig.8
+++ b/sbin/mdconfig/mdconfig.8
@@ -129,6 +129,11 @@ Enable clustering on this disk.
 .Xc
 Enable/Disable compression features to reduce memory usage.
 .It Xo
+.Oo Cm no Oc Ns Cm force
+.Xc
+Disable/Enable extra sanity checks to prevent the user from doing something
+that might adversely affect the system.
+.It Xo
 .Oo Cm no Oc Ns Cm readonly
 .Xc
 Enable/Disable readonly mode.
diff --git a/sbin/mdconfig/mdconfig.c b/sbin/mdconfig/mdconfig.c
index 53d04807936e..3b2d642e7fe7 100644
--- a/sbin/mdconfig/mdconfig.c
+++ b/sbin/mdconfig/mdconfig.c
@@ -120,6 +120,10 @@ main(int argc, char **argv)
 				mdio.md_options |= MD_COMPRESS;
 			else if (!strcmp(optarg, "nocompress"))
 				mdio.md_options &= ~MD_COMPRESS;
+			else if (!strcmp(optarg, "force"))
+				mdio.md_options |= MD_FORCE;
+			else if (!strcmp(optarg, "noforce"))
+				mdio.md_options &= ~MD_FORCE;
 			else if (!strcmp(optarg, "reserve"))
 				mdio.md_options |= MD_RESERVE;
 			else if (!strcmp(optarg, "noreserve"))
diff --git a/sys/dev/md/md.c b/sys/dev/md/md.c
index ec82b330c1b2..dbec37a315fa 100644
--- a/sys/dev/md/md.c
+++ b/sys/dev/md/md.c
@@ -553,6 +553,7 @@ mdcreate_preload(struct md_ioctl *mdio)
 	sc->type = MD_PRELOAD;
 	sc->secsize = DEV_BSIZE;
 	sc->nsect = mdio->md_size;
+	sc->flags = mdio->md_options & MD_FORCE;
 	/* Cast to pointer size, then to pointer to avoid warning */
 	sc->pl_ptr = (u_char *)(uintptr_t)mdio->md_base;	
 	sc->pl_len = (mdio->md_size << DEV_BSHIFT);
@@ -587,7 +588,7 @@ mdcreate_malloc(struct md_ioctl *mdio)
 	sc->type = MD_MALLOC;
 	sc->secsize = DEV_BSIZE;
 	sc->nsect = mdio->md_size;
-	sc->flags = mdio->md_options & MD_COMPRESS;
+	sc->flags = mdio->md_options & (MD_COMPRESS | MD_FORCE);
 	MALLOC(sc->secp, u_char **, sc->nsect * sizeof(u_char *), M_MD, M_WAITOK | M_ZERO);
 	if (mdio->md_options & MD_RESERVE) {
 		for (u = 0; u < sc->nsect; u++)
@@ -658,6 +659,7 @@ mdcreate_vnode(struct md_ioctl *mdio, struct proc *p)
 		return (EBUSY);
 
 	sc->type = MD_VNODE;
+	sc->flags = mdio->md_options & MD_FORCE;
 
 	flags = FREAD|FWRITE;
 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, mdio->md_file, p);
@@ -776,6 +778,7 @@ mdcreate_swap(struct md_ioctl *mdio, struct proc *p)
 	sc->secsize = PAGE_SIZE;
 	sc->nsect = mdio->md_size / (PAGE_SIZE / DEV_BSIZE);
 	sc->object = vm_pager_allocate(OBJT_SWAP, NULL, sc->secsize * (vm_offset_t)sc->nsect, VM_PROT_DEFAULT, 0);
+	sc->flags = mdio->md_options & MD_FORCE;
 	if (mdio->md_options & MD_RESERVE) {
 		if (swap_pager_reserve(sc->object, 0, sc->nsect) < 0) {
 			vm_pager_deallocate(sc->object);
@@ -827,7 +830,7 @@ mdctlioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct proc *p)
 		sc = mdfind(mdio->md_unit);
 		if (sc == NULL)
 			return (ENOENT);
-		if (sc->opencount != 0)
+		if (sc->opencount != 0 && !(sc->flags & MD_FORCE))
 			return (EBUSY);
 		switch(sc->type) {
 		case MD_VNODE:
diff --git a/sys/sys/mdioctl.h b/sys/sys/mdioctl.h
index 6ebda6b8dfaf..6b16fde61f14 100644
--- a/sys/sys/mdioctl.h
+++ b/sys/sys/mdioctl.h
@@ -84,5 +84,6 @@ struct md_ioctl {
 #define MD_AUTOUNIT	0x04	/* Assign next free unit */
 #define MD_READONLY	0x08	/* Readonly mode */
 #define MD_COMPRESS	0x10	/* Compression mode */
+#define MD_FORCE	0x20	/* Don't try to prevent foot-shooting */
 
 #endif	/* _SYS_MDIOCTL_H_*/