diff --git a/sys/cam/ctl/ctl.c b/sys/cam/ctl/ctl.c
index cd0111416b9a..7772910e2d5e 100644
--- a/sys/cam/ctl/ctl.c
+++ b/sys/cam/ctl/ctl.c
@@ -357,7 +357,6 @@ static struct ctl_logical_block_provisioning_page lbp_page_changeable = {{
 static int rcv_sync_msg;
 static int persis_offset;
 static uint8_t ctl_pause_rtr;
-static int     ctl_is_single = 1;
 
 SYSCTL_NODE(_kern_cam, OID_AUTO, ctl, CTLFLAG_RD, 0, "CAM Target Layer");
 static int worker_threads = -1;
@@ -969,13 +968,43 @@ ctl_copy_sense_data(union ctl_ha_msg *src, union ctl_io *dest)
 	dest->io_hdr.status = src->hdr.status;
 }
 
+static int
+ctl_ha_state_sysctl(SYSCTL_HANDLER_ARGS)
+{
+	struct ctl_softc *softc = (struct ctl_softc *)arg1;
+	struct ctl_lun *lun;
+	int error, value, i;
+
+	if (softc->flags & CTL_FLAG_ACTIVE_SHELF)
+		value = 0;
+	else
+		value = 1;
+
+	error = sysctl_handle_int(oidp, &value, 0, req);
+	if ((error != 0) || (req->newptr == NULL))
+		return (error);
+
+	mtx_lock(&softc->ctl_lock);
+	if (value == 0)
+		softc->flags |= CTL_FLAG_ACTIVE_SHELF;
+	else
+		softc->flags &= ~CTL_FLAG_ACTIVE_SHELF;
+	STAILQ_FOREACH(lun, &softc->lun_list, links) {
+		mtx_lock(&lun->lun_lock);
+		for (i = 0; i < CTL_MAX_INITIATORS; i++)
+			lun->pending_ua[i] |= CTL_UA_ASYM_ACC_CHANGE;
+		mtx_unlock(&lun->lun_lock);
+	}
+	mtx_unlock(&softc->ctl_lock);
+	return (0);
+}
+
 static int
 ctl_init(void)
 {
 	struct ctl_softc *softc;
 	struct ctl_io_pool *internal_pool, *emergency_pool, *other_pool;
 	struct ctl_port *port;
-        uint8_t sc_id =0;
 	int i, error, retval;
 	//int isc_retval;
 
@@ -1033,16 +1062,17 @@ ctl_init(void)
 	 * In Copan's HA scheme, the "master" and "slave" roles are
 	 * figured out through the slot the controller is in.  Although it
 	 * is an active/active system, someone has to be in charge.
- 	 */
-#ifdef NEEDTOPORT
-        scmicro_rw(SCMICRO_GET_SHELF_ID, &sc_id);
-#endif
-
-        if (sc_id == 0) {
-		softc->flags |= CTL_FLAG_MASTER_SHELF;
-		persis_offset = 0;
+	 */
+	SYSCTL_ADD_INT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
+	    OID_AUTO, "ha_id", CTLFLAG_RDTUN, &softc->ha_id, 0,
+	    "HA head ID (0 - no HA)");
+	if (softc->ha_id == 0) {
+		softc->flags |= CTL_FLAG_ACTIVE_SHELF;
+		softc->is_single = 1;
+		softc->port_offset = 0;
 	} else
-		persis_offset = CTL_MAX_INITIATORS;
+		softc->port_offset = (softc->ha_id - 1) * CTL_MAX_PORTS;
+	persis_offset = softc->port_offset * CTL_MAX_INIT_PER_PORT;
 
 	/*
 	 * XXX KDM need to figure out where we want to get our target ID
@@ -1155,12 +1185,15 @@ ctl_init(void)
 	port->max_targets = 15;
 	port->max_target_id = 15;
 
-	if (ctl_port_register(&softc->ioctl_info.port,
-	                  (softc->flags & CTL_FLAG_MASTER_SHELF)) != 0) {
+	if (ctl_port_register(&softc->ioctl_info.port) != 0) {
 		printf("ctl: ioctl front end registration failed, will "
 		       "continue anyway\n");
 	}
 
+	SYSCTL_ADD_PROC(&softc->sysctl_ctx,SYSCTL_CHILDREN(softc->sysctl_tree),
+	    OID_AUTO, "ha_state", CTLTYPE_INT | CTLFLAG_RWTUN,
+	    softc, 0, ctl_ha_state_sysctl, "I", "HA state for this head");
+
 #ifdef CTL_IO_DELAY
 	if (sizeof(struct callout) > CTL_TIMER_BYTES) {
 		printf("sizeof(struct callout) %zd > CTL_TIMER_BYTES %zd\n",
@@ -1262,10 +1295,10 @@ ctl_close(struct cdev *dev, int flags, int fmt, struct thread *td)
 int
 ctl_port_enable(ctl_port_type port_type)
 {
-	struct ctl_softc *softc;
+	struct ctl_softc *softc = control_softc;
 	struct ctl_port *port;
 
-	if (ctl_is_single == 0) {
+	if (softc->is_single == 0) {
 		union ctl_ha_msg msg_info;
 		int isc_retval;
 
@@ -1290,8 +1323,6 @@ ctl_port_enable(ctl_port_type port_type)
 #endif
 	}
 
-	softc = control_softc;
-
 	STAILQ_FOREACH(port, &softc->port_list, links) {
 		if (port_type & port->port_type)
 		{
@@ -7440,8 +7471,8 @@ ctl_report_tagret_port_groups(struct ctl_scsiio *ctsio)
 {
 	struct scsi_maintenance_in *cdb;
 	int retval;
-	int alloc_len, ext, total_len = 0, g, p, pc, pg;
-	int num_target_port_groups, num_target_ports, single;
+	int alloc_len, ext, total_len = 0, g, p, pc, pg, gs, os;
+	int num_target_port_groups, num_target_ports;
 	struct ctl_lun *lun;
 	struct ctl_softc *softc;
 	struct ctl_port *port;
@@ -7475,8 +7506,7 @@ ctl_report_tagret_port_groups(struct ctl_scsiio *ctsio)
 		return(retval);
 	}
 
-	single = ctl_is_single;
-	if (single)
+	if (softc->is_single)
 		num_target_port_groups = 1;
 	else
 		num_target_port_groups = NUM_TARGET_PORT_GROUPS;
@@ -7532,18 +7562,26 @@ ctl_report_tagret_port_groups(struct ctl_scsiio *ctsio)
 		tpg_desc = &rtg_ptr->groups[0];
 	}
 
-	pg = ctsio->io_hdr.nexus.targ_port / CTL_MAX_PORTS;
 	mtx_lock(&softc->ctl_lock);
+	pg = softc->port_offset / CTL_MAX_PORTS;
+	if (softc->flags & CTL_FLAG_ACTIVE_SHELF) {
+		if (softc->ha_mode == CTL_HA_MODE_ACT_STBY) {
+			gs = TPG_ASYMMETRIC_ACCESS_OPTIMIZED;
+			os = TPG_ASYMMETRIC_ACCESS_STANDBY;
+		} else if (lun->flags & CTL_LUN_PRIMARY_SC) {
+			gs = TPG_ASYMMETRIC_ACCESS_OPTIMIZED;
+			os = TPG_ASYMMETRIC_ACCESS_NONOPTIMIZED;
+		} else {
+			gs = TPG_ASYMMETRIC_ACCESS_NONOPTIMIZED;
+			os = TPG_ASYMMETRIC_ACCESS_OPTIMIZED;
+		}
+	} else {
+		gs = TPG_ASYMMETRIC_ACCESS_STANDBY;
+		os = TPG_ASYMMETRIC_ACCESS_OPTIMIZED;
+	}
 	for (g = 0; g < num_target_port_groups; g++) {
-		if (g == pg)
-			tpg_desc->pref_state = TPG_PRIMARY |
-			    TPG_ASYMMETRIC_ACCESS_OPTIMIZED;
-		else
-			tpg_desc->pref_state =
-			    TPG_ASYMMETRIC_ACCESS_NONOPTIMIZED;
-		tpg_desc->support = TPG_AO_SUP;
-		if (!single)
-			tpg_desc->support |= TPG_AN_SUP;
+		tpg_desc->pref_state = (g == pg) ? gs : os;
+		tpg_desc->support = TPG_AO_SUP | TPG_AN_SUP | TPG_S_SUP;
 		scsi_ulto2b(g + 1, tpg_desc->target_port_group);
 		tpg_desc->status = TPG_IMPLICIT;
 		pc = 0;
@@ -10192,12 +10230,11 @@ ctl_inquiry_evpd_scsi_ports(struct ctl_scsiio *ctsio, int alloc_len)
 	struct ctl_lun *lun;
 	struct ctl_port *port;
 	int data_len, num_target_ports, iid_len, id_len, g, pg, p;
-	int num_target_port_groups, single;
+	int num_target_port_groups;
 
 	lun = (struct ctl_lun *)ctsio->io_hdr.ctl_private[CTL_PRIV_LUN].ptr;
 
-	single = ctl_is_single;
-	if (single)
+	if (softc->is_single)
 		num_target_port_groups = 1;
 	else
 		num_target_port_groups = NUM_TARGET_PORT_GROUPS;
@@ -10257,10 +10294,7 @@ ctl_inquiry_evpd_scsi_ports(struct ctl_scsiio *ctsio, int alloc_len)
 	pd = &sp->design[0];
 
 	mtx_lock(&softc->ctl_lock);
-	if (softc->flags & CTL_FLAG_MASTER_SHELF)
-		pg = 0;
-	else
-		pg = 1;
+	pg = softc->port_offset / CTL_MAX_PORTS;
 	for (g = 0; g < num_target_port_groups; g++) {
 		STAILQ_FOREACH(port, &softc->port_list, links) {
 			if ((port->status & CTL_PORT_STATUS_ONLINE) == 0)
@@ -11342,15 +11376,12 @@ ctl_scsiio_lun_check(struct ctl_softc *ctl_softc, struct ctl_lun *lun,
 	 * If this shelf is a secondary shelf controller, we have to reject
 	 * any media access commands.
 	 */
-#if 0
-	/* No longer needed for HA */
-	if (((ctl_softc->flags & CTL_FLAG_MASTER_SHELF) == 0)
-	 && ((entry->flags & CTL_CMD_FLAG_OK_ON_SECONDARY) == 0)) {
+	if ((ctl_softc->flags & CTL_FLAG_ACTIVE_SHELF) == 0 &&
+	    (entry->flags & CTL_CMD_FLAG_OK_ON_SECONDARY) == 0) {
 		ctl_set_lun_standby(ctsio);
 		retval = 1;
 		goto bailout;
 	}
-#endif
 
 	if (entry->pattern & CTL_LUN_PAT_WRITE) {
 		if (lun->flags & CTL_LUN_READONLY) {
@@ -14405,7 +14436,7 @@ ctl_isc_start(struct ctl_ha_component *c, ctl_ha_state state)
 
 	// UNKNOWN->HA or UNKNOWN->SINGLE (bootstrap)
 	if (c->state == CTL_HA_STATE_UNKNOWN ) {
-		ctl_is_single = 0;
+		control_softc->is_single = 0;
 		if (ctl_ha_msg_create(CTL_HA_CHAN_CTL, ctl_isc_event_handler)
 		    != CTL_HA_STATUS_SUCCESS) {
 			printf("ctl_isc_start: ctl_ha_msg_create failed.\n");
@@ -14415,14 +14446,14 @@ ctl_isc_start(struct ctl_ha_component *c, ctl_ha_state state)
 		&& CTL_HA_STATE_IS_SINGLE(state)){
 		// HA->SINGLE transition
 	        ctl_failover();
-		ctl_is_single = 1;
+		control_softc->is_single = 1;
 	} else {
 		printf("ctl_isc_start:Invalid state transition %X->%X\n",
 		       c->state, state);
 		ret = CTL_HA_COMP_STATUS_ERROR;
 	}
 	if (CTL_HA_STATE_IS_SINGLE(state))
-		ctl_is_single = 1;
+		control_softc->is_single = 1;
 
 	c->state = state;
 	c->status = ret;
diff --git a/sys/cam/ctl/ctl_cmd_table.c b/sys/cam/ctl/ctl_cmd_table.c
index fedc11001e96..5ae50575e674 100644
--- a/sys/cam/ctl/ctl_cmd_table.c
+++ b/sys/cam/ctl/ctl_cmd_table.c
@@ -800,12 +800,18 @@ const struct ctl_cmd_entry ctl_cmd_table[256] =
 
 /* 3B WRITE BUFFER */
 {ctl_write_buffer, CTL_SERIDX_MD_SEL, CTL_CMD_FLAG_OK_ON_BOTH |
+				      CTL_CMD_FLAG_OK_ON_STOPPED |
+				      CTL_CMD_FLAG_OK_ON_INOPERABLE |
+				      CTL_CMD_FLAG_OK_ON_OFFLINE |
 				      CTL_FLAG_DATA_OUT,
  CTL_LUN_PAT_NONE,
  10, {0x1f, 0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x07}},
 
 /* 3C READ BUFFER */
 {ctl_read_buffer, CTL_SERIDX_MD_SNS, CTL_CMD_FLAG_OK_ON_BOTH |
+				     CTL_CMD_FLAG_OK_ON_STOPPED |
+				     CTL_CMD_FLAG_OK_ON_INOPERABLE |
+				     CTL_CMD_FLAG_OK_ON_OFFLINE |
 				     CTL_FLAG_DATA_IN |
 				     CTL_CMD_FLAG_ALLOW_ON_PR_WRESV,
  CTL_LUN_PAT_NONE,
diff --git a/sys/cam/ctl/ctl_frontend.c b/sys/cam/ctl/ctl_frontend.c
index 8a992cc0ba74..70470933bd52 100644
--- a/sys/cam/ctl/ctl_frontend.c
+++ b/sys/cam/ctl/ctl_frontend.c
@@ -136,7 +136,7 @@ ctl_frontend_find(char *frontend_name)
 }
 
 int
-ctl_port_register(struct ctl_port *port, int master_shelf)
+ctl_port_register(struct ctl_port *port)
 {
 	struct ctl_io_pool *pool;
 	int port_num;
@@ -193,7 +193,7 @@ ctl_port_register(struct ctl_port *port, int master_shelf)
 		STAILQ_INIT(&port->options);
 
 	mtx_lock(&control_softc->ctl_lock);
-	port->targ_port = port_num + (master_shelf != 0 ? 0 : CTL_MAX_PORTS);
+	port->targ_port = port_num + control_softc->port_offset;
 	STAILQ_INSERT_TAIL(&port->frontend->port_list, port, fe_links);
 	STAILQ_INSERT_TAIL(&control_softc->port_list, port, links);
 	control_softc->ctl_ports[port_num] = port;
diff --git a/sys/cam/ctl/ctl_frontend.h b/sys/cam/ctl/ctl_frontend.h
index 825ff50a0bca..06ae5a14330c 100644
--- a/sys/cam/ctl/ctl_frontend.h
+++ b/sys/cam/ctl/ctl_frontend.h
@@ -278,7 +278,7 @@ struct ctl_frontend * ctl_frontend_find(char *frontend_name);
  * This may block until resources are allocated.  Called at FETD module load
  * time. Returns 0 for success, non-zero for failure.
  */
-int ctl_port_register(struct ctl_port *port, int master_SC);
+int ctl_port_register(struct ctl_port *port);
 
 /*
  * Called at FETD module unload time.
diff --git a/sys/cam/ctl/ctl_frontend_cam_sim.c b/sys/cam/ctl/ctl_frontend_cam_sim.c
index 7cdd5b7972c2..93c12f48e417 100644
--- a/sys/cam/ctl/ctl_frontend_cam_sim.c
+++ b/sys/cam/ctl/ctl_frontend_cam_sim.c
@@ -164,7 +164,7 @@ cfcs_init(void)
 	port->max_targets = 1;
 	port->max_target_id = 15;
 
-	retval = ctl_port_register(port, /*master_SC*/ 1);
+	retval = ctl_port_register(port);
 	if (retval != 0) {
 		printf("%s: ctl_port_register() failed with error %d!\n",
 		       __func__, retval);
diff --git a/sys/cam/ctl/ctl_frontend_internal.c b/sys/cam/ctl/ctl_frontend_internal.c
index ac972f306420..1d74737f3ef0 100644
--- a/sys/cam/ctl/ctl_frontend_internal.c
+++ b/sys/cam/ctl/ctl_frontend_internal.c
@@ -244,8 +244,6 @@ cfi_init(void)
 	memset(softc, 0, sizeof(*softc));
 
 	mtx_init(&softc->lock, "CTL frontend mutex", NULL, MTX_DEF);
-	softc->flags |= CTL_FLAG_MASTER_SHELF;
-
 	STAILQ_INIT(&softc->lun_list);
 	STAILQ_INIT(&softc->metatask_list);
 	sprintf(softc->fe_name, "kernel");
@@ -264,7 +262,7 @@ cfi_init(void)
 	port->max_targets = 15;
 	port->max_target_id = 15;
 
-	if (ctl_port_register(port, (softc->flags & CTL_FLAG_MASTER_SHELF)) != 0) 
+	if (ctl_port_register(port) != 0)
 	{
 		printf("%s: internal frontend registration failed\n", __func__);
 		return (0);
diff --git a/sys/cam/ctl/ctl_frontend_iscsi.c b/sys/cam/ctl/ctl_frontend_iscsi.c
index 408b86a21fc7..b434a6b932f2 100644
--- a/sys/cam/ctl/ctl_frontend_iscsi.c
+++ b/sys/cam/ctl/ctl_frontend_iscsi.c
@@ -2046,7 +2046,7 @@ cfiscsi_ioctl_port_create(struct ctl_req *req)
 	desc->length = idlen;
 	strlcpy(desc->identifier, target, idlen);
 
-	retval = ctl_port_register(port, /*master_SC*/ 1);
+	retval = ctl_port_register(port);
 	if (retval != 0) {
 		ctl_free_opts(&port->options);
 		cfiscsi_target_release(ct);
diff --git a/sys/cam/ctl/ctl_ha.h b/sys/cam/ctl/ctl_ha.h
index 6293c7ce1701..0c004b3c498b 100644
--- a/sys/cam/ctl/ctl_ha.h
+++ b/sys/cam/ctl/ctl_ha.h
@@ -38,6 +38,8 @@
 /*
  * CTL High Availability Modes:
  *
+ * CTL_HA_MODE_ACT_STBY:  One side is in Active state and processing commands,
+ *			  the other side is in Standby state, returning errors.
  * CTL_HA_MODE_SER_ONLY:  Commands are serialized to the other side.  Write
  *			  mirroring and read re-direction are assumed to
  * 			  happen in the back end.
@@ -46,6 +48,7 @@
  */
 
 typedef enum {
+	CTL_HA_MODE_ACT_STBY,
 	CTL_HA_MODE_SER_ONLY,
 	CTL_HA_MODE_XFER
 } ctl_ha_mode;
diff --git a/sys/cam/ctl/ctl_private.h b/sys/cam/ctl/ctl_private.h
index 7b66c7f8a974..e3ebe7a8258a 100644
--- a/sys/cam/ctl/ctl_private.h
+++ b/sys/cam/ctl/ctl_private.h
@@ -442,7 +442,7 @@ struct ctl_lun {
 
 typedef enum {
 	CTL_FLAG_REAL_SYNC	= 0x02,
-	CTL_FLAG_MASTER_SHELF	= 0x04
+	CTL_FLAG_ACTIVE_SHELF	= 0x04
 } ctl_gen_flags;
 
 #define CTL_MAX_THREADS		16
@@ -467,6 +467,10 @@ struct ctl_softc {
 	int num_luns;
 	ctl_gen_flags flags;
 	ctl_ha_mode ha_mode;
+	int ha_id;
+	int ha_state;
+	int is_single;
+	int port_offset;
 	int inquiry_pq_no_lun;
 	struct sysctl_ctx_list sysctl_ctx;
 	struct sysctl_oid *sysctl_tree;
diff --git a/sys/cam/ctl/ctl_tpc_local.c b/sys/cam/ctl/ctl_tpc_local.c
index 8fb797865ad2..97a5f984e267 100644
--- a/sys/cam/ctl/ctl_tpc_local.c
+++ b/sys/cam/ctl/ctl_tpc_local.c
@@ -87,7 +87,6 @@ CTL_FRONTEND_DECLARE(ctltpc, tpcl_frontend);
 static int
 tpcl_init(void)
 {
-	struct ctl_softc *softc = control_softc;
 	struct tpcl_softc *tsoftc = &tpcl_softc;
 	struct ctl_port *port;
 	struct scsi_transportid_spi *tid;
@@ -112,7 +111,7 @@ tpcl_init(void)
 	port->max_target_id = 0;
 	port->max_initiators = 1;
 
-	if (ctl_port_register(port, (softc->flags & CTL_FLAG_MASTER_SHELF)) != 0) 
+	if (ctl_port_register(port) != 0)
 	{
 		printf("%s: tpc frontend registration failed\n", __func__);
 		return (0);
diff --git a/sys/cam/ctl/scsi_ctl.c b/sys/cam/ctl/scsi_ctl.c
index ff80f3e6f02b..cbdf36ccab18 100644
--- a/sys/cam/ctl/scsi_ctl.c
+++ b/sys/cam/ctl/scsi_ctl.c
@@ -425,7 +425,7 @@ ctlfeasync(void *callback_arg, uint32_t code, struct cam_path *path, void *arg)
 		printf("%s: calling ctl_port_register() for %s%d\n",
 		       __func__, cpi->dev_name, cpi->unit_number);
 #endif
-		retval = ctl_port_register(port, /*master_SC*/ 1);
+		retval = ctl_port_register(port);
 		if (retval != 0) {
 			printf("%s: ctl_port_register() failed with "
 			       "error %d!\n", __func__, retval);