diff --git a/scst/src/scst_copy_mgr.c b/scst/src/scst_copy_mgr.c
index c59233ba8..049ac0529 100644
--- a/scst/src/scst_copy_mgr.c
+++ b/scst/src/scst_copy_mgr.c
@@ -2550,7 +2550,7 @@ static int scst_cm_dev_register(struct scst_device *dev)
 	};
 
 	res = scst_acg_add_lun(scst_cm_tgt->default_acg,
-		scst_cm_tgt->tgt_luns_kobj, dev, lun, false, false, &acg_dev);
+		scst_cm_tgt->tgt_luns_kobj, dev, lun, 0, &acg_dev);
 	if (res != 0)
 		goto out_err;
 
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 9d15d4c8e..c73c54ba8 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -4407,8 +4407,8 @@ out:
 
 /* The activity supposed to be suspended and scst_mutex held */
 int scst_acg_add_lun(struct scst_acg *acg, struct kobject *parent,
-	struct scst_device *dev, uint64_t lun, int read_only,
-	bool gen_scst_report_luns_changed, struct scst_acg_dev **out_acg_dev)
+	struct scst_device *dev, uint64_t lun, unsigned int flags,
+	struct scst_acg_dev **out_acg_dev)
 {
 	int res;
 	struct scst_acg_dev *acg_dev;
@@ -4429,7 +4429,7 @@ int scst_acg_add_lun(struct scst_acg *acg, struct kobject *parent,
 		res = -ENOMEM;
 		goto out;
 	}
-	acg_dev->acg_dev_rd_only = read_only;
+	acg_dev->acg_dev_rd_only = ((flags & SCST_ADD_LUN_READ_ONLY) != 0);
 	if (dev->dev_dif_mode & SCST_DIF_MODE_DEV_STORE) {
 		/* Devices are allowed to store only CRCs */
 		acg_dev->acg_dev_dif_guard_format = SCST_DIF_GUARD_FORMAT_CRC;
@@ -4459,12 +4459,12 @@ int scst_acg_add_lun(struct scst_acg *acg, struct kobject *parent,
 	if (res != 0)
 		goto out_free;
 
-	if (gen_scst_report_luns_changed)
+	if (flags & SCST_ADD_LUN_GEN_UA)
 		scst_report_luns_changed(acg);
 
 	PRINT_INFO("Added device %s to group %s (LUN %lld, "
-		"rd_only %d) to target %s", dev->virt_name, acg->acg_name,
-		lun, read_only, acg->tgt ? acg->tgt->tgt_name : "?");
+		"flags 0x%x) to target %s", dev->virt_name, acg->acg_name,
+		lun, flags, acg->tgt ? acg->tgt->tgt_name : "?");
 
 	if (out_acg_dev != NULL)
 		*out_acg_dev = acg_dev;
@@ -4585,7 +4585,7 @@ out:
 
 int scst_acg_repl_lun(struct scst_acg *acg, struct kobject *parent,
 		      struct scst_device *dev, uint64_t lun,
-		      bool read_only, bool gen_ua)
+		      unsigned int flags)
 {
 	struct scst_acg_dev *acg_dev;
 	struct scst_tgt_dev *tgt_dev, *tt;
@@ -4598,12 +4598,11 @@ int scst_acg_repl_lun(struct scst_acg *acg, struct kobject *parent,
 
 	acg_dev = __scst_acg_del_lun(acg, lun, &tgt_dev_list);
 
-	res = scst_acg_add_lun(acg, parent, dev, lun, read_only, !acg_dev,
-			       NULL);
+	res = scst_acg_add_lun(acg, parent, dev, lun, flags, NULL);
 	if (res != 0)
 		goto out;
 
-	if (acg_dev && gen_ua) {
+	if (acg_dev && (flags & SCST_REPL_LUN_GEN_UA)) {
 		list_for_each_entry(tgt_dev, &dev->dev_tgt_dev_list,
 				    dev_tgt_dev_list_entry) {
 			if (tgt_dev->acg_dev->acg == acg &&
diff --git a/scst/src/scst_priv.h b/scst/src/scst_priv.h
index 010914212..0181356fc 100644
--- a/scst/src/scst_priv.h
+++ b/scst/src/scst_priv.h
@@ -364,14 +364,19 @@ void scst_sess_free_tgt_devs(struct scst_session *sess);
 struct scst_tgt_dev *scst_lookup_tgt_dev(struct scst_session *sess, u64 lun);
 void scst_nexus_loss(struct scst_tgt_dev *tgt_dev, bool queue_UA);
 
+#define SCST_ADD_LUN_READ_ONLY	1
+#define SCST_ADD_LUN_GEN_UA	2
+#define SCST_ADD_LUN_CM		4
+#define SCST_REPL_LUN_GEN_UA	8
+
 int scst_acg_add_lun(struct scst_acg *acg, struct kobject *parent,
-	struct scst_device *dev, uint64_t lun, int read_only,
-	bool gen_scst_report_luns_changed, struct scst_acg_dev **out_acg_dev);
+	struct scst_device *dev, uint64_t lun, unsigned int flags,
+	struct scst_acg_dev **out_acg_dev);
 int scst_acg_del_lun(struct scst_acg *acg, uint64_t lun,
-	bool gen_scst_report_luns_changed);
+	bool gen_report_luns_changed);
 int scst_acg_repl_lun(struct scst_acg *acg, struct kobject *parent,
-		      struct scst_device *dev, uint64_t lun, bool read_only,
-		      bool gen_ua);
+		      struct scst_device *dev, uint64_t lun,
+		      unsigned int flags);
 
 int scst_acg_add_acn(struct scst_acg *acg, const char *name);
 #ifdef CONFIG_SCST_PROC
diff --git a/scst/src/scst_sysfs.c b/scst/src/scst_sysfs.c
index d6ffb482d..eb1ab9274 100644
--- a/scst/src/scst_sysfs.c
+++ b/scst/src/scst_sysfs.c
@@ -1405,10 +1405,14 @@ static int __scst_process_luns_mgmt_store(char *buffer,
 
 	switch (action) {
 	case SCST_LUN_ACTION_ADD:
+	{
+		unsigned int flags = SCST_ADD_LUN_GEN_UA;
+
 		res = scst_parse_add_repl_param(acg, dev, pp, &virt_lun,
 						&read_only);
 		if (res != 0)
 			goto out_unlock;
+
 		acg_dev = NULL;
 		list_for_each_entry(acg_dev_tmp, &acg->acg_dev_list,
 				    acg_dev_list_entry) {
@@ -1417,31 +1421,40 @@ static int __scst_process_luns_mgmt_store(char *buffer,
 				break;
 			}
 		}
-		if (acg_dev) {
-			PRINT_ERROR("virt lun %ld already exists in "
-				    "group %s", virt_lun, acg->acg_name);
+
+		if (acg_dev != NULL) {
+			PRINT_ERROR("virt lun %ld already exists in group %s",
+				    virt_lun, acg->acg_name);
 			res = -EEXIST;
 			goto out_unlock;
 		}
 
+		if (read_only)
+			flags |= SCST_ADD_LUN_READ_ONLY;
 		res = scst_acg_add_lun(acg,
 			tgt_kobj ? tgt->tgt_luns_kobj : acg->luns_kobj,
-			dev, virt_lun, read_only, true, NULL);
+			dev, virt_lun, flags, NULL);
 		if (res != 0)
 			goto out_unlock;
-
 		break;
+	}
 	case SCST_LUN_ACTION_REPLACE:
+	{
+		unsigned int flags = (read_only ? SCST_ADD_LUN_READ_ONLY : 0) |
+				  (replace_gen_ua ? SCST_REPL_LUN_GEN_UA : 0);
+
 		res = scst_parse_add_repl_param(acg, dev, pp, &virt_lun,
 						&read_only);
 		if (res != 0)
 			goto out_unlock;
-		res = scst_acg_repl_lun(acg,
-			tgt_kobj ? tgt->tgt_luns_kobj : acg->luns_kobj,
-			dev, virt_lun, read_only, replace_gen_ua);
+
+		res = scst_acg_repl_lun(acg, tgt_kobj ? tgt->tgt_luns_kobj :
+					acg->luns_kobj, dev, virt_lun,
+					flags);
 		if (res != 0)
 			goto out_unlock;
 		break;
+	}
 	case SCST_LUN_ACTION_DEL:
 		p = scst_get_next_lexem(&pp);
 		res = kstrtoul(p, 0, &virt_lun);