diff --git a/WHATS_NEW b/WHATS_NEW
index 448f3064e..dc62d77d5 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.98 -
 =================================
+  Fix inability to create, extend or convert to a large (> 1TiB) RAID LV.
   Add (p)artial attribute to lvs.
   Don't try to issue discards to a missing PV to avoid segfault.
   Prevent lvremove from removing LVs that have any part missing.
diff --git a/lib/metadata/lv_manip.c b/lib/metadata/lv_manip.c
index 6c62bb39e..f2d99b8ff 100644
--- a/lib/metadata/lv_manip.c
+++ b/lib/metadata/lv_manip.c
@@ -2660,7 +2660,17 @@ static int _lv_extend_layered_lv(struct alloc_handle *ah,
 	seg->area_len += extents;
 	seg->len += extents;
 	lv->le_count += extents;
-	lv->size += (uint64_t) extents *lv->vg->extent_size;
+	lv->size += (uint64_t) extents * lv->vg->extent_size;
+
+	/*
+	 * The MD bitmap is limited to being able to track 2^21 regions.
+	 * The region_size must be adjusted to meet that criteria.
+	 */
+	while (seg_is_raid(seg) && (seg->region_size < (lv->size / (1 << 21)))) {
+		seg->region_size *= 2;
+		log_very_verbose("Forced to adjust RAID region_size to %uS",
+				 seg->region_size);
+	}
 
 	return 1;
 }
diff --git a/lib/metadata/raid_manip.c b/lib/metadata/raid_manip.c
index 0266013df..98a7db3e1 100644
--- a/lib/metadata/raid_manip.c
+++ b/lib/metadata/raid_manip.c
@@ -731,6 +731,12 @@ static int _raid_add_images(struct logical_volume *lv,
 		seg = first_seg(lv);
 		seg_lv(seg, 0)->status |= RAID_IMAGE | LVM_READ | LVM_WRITE;
 		seg->region_size = RAID_REGION_SIZE;
+		/* MD's bitmap is limited to tracking 2^21 regions */
+		while (seg->region_size < (lv->size / (1 << 21))) {
+			seg->region_size *= 2;
+			log_very_verbose("Setting RAID1 region_size to %uS",
+					 seg->region_size);
+		}
 		seg->segtype = get_segtype_from_string(lv->vg->cmd, "raid1");
 		if (!seg->segtype)
 			return_0;
diff --git a/test/shell/lvcreate-large.sh b/test/shell/lvcreate-large.sh
index b61cccaeb..127b43454 100644
--- a/test/shell/lvcreate-large.sh
+++ b/test/shell/lvcreate-large.sh
@@ -13,28 +13,75 @@
 
 . lib/test
 
-aux prepare_vg 4
+aux prepare_vg 5
 
-lvcreate -s -l 100%FREE -n $lv $vg --virtualsize 1024T
+lvcreate -s -l 20%FREE -n $lv1 $vg --virtualsize 256T
+lvcreate -s -l 20%FREE -n $lv2 $vg --virtualsize 256T
+lvcreate -s -l 20%FREE -n $lv3 $vg --virtualsize 256T
+lvcreate -s -l 20%FREE -n $lv4 $vg --virtualsize 256T
+lvcreate -s -l 20%FREE -n $lv5 $vg --virtualsize 256T
 
 #FIXME this should be 1024T
 #check lv_field $vg/$lv size "128.00m"
 
 aux lvmconf 'devices/filter = [ "a/dev\/mapper\/.*$/", "a/dev\/LVMTEST/", "r/.*/" ]'
 
-pvcreate $DM_DEV_DIR/$vg/$lv
-vgcreate -c n $vg1 $DM_DEV_DIR/$vg/$lv
+pvcreate $DM_DEV_DIR/$vg/$lv[12345]
+vgcreate -c n $vg1 $DM_DEV_DIR/$vg/$lv[12345]
 
 lvcreate -l 100%FREE -n $lv1 $vg1
-check lv_field $vg1/$lv1 size "1024.00t"
+check lv_field $vg1/$lv1 size "1.25p"
 lvresize -f -l 72%VG $vg1/$lv1
-check lv_field $vg1/$lv1 size "737.28t"
+check lv_field $vg1/$lv1 size "921.60t"
 lvremove -ff $vg1/$lv1
 
 lvcreate -l 100%VG -n $lv1 $vg1
-check lv_field $vg1/$lv1 size "1024.00t"
+check lv_field $vg1/$lv1 size "1.25p"
 lvresize -f -l 72%VG $vg1/$lv1
-check lv_field $vg1/$lv1 size "737.28t"
+check lv_field $vg1/$lv1 size "921.60t"
 lvremove -ff $vg1/$lv1
 
-lvremove -ff $vg/$lv
+if aux target_at_least dm-raid 1 1 0; then
+	# bz837927 START
+
+	#
+	# Create large RAID LVs
+	#
+	# We need '--nosync' or our virtual devices won't work
+	lvcreate --type raid1 -m 1 -L 200T -n $lv1 $vg1 --nosync
+	check lv_field $vg1/$lv1 size "200.00t"
+	lvremove -ff $vg1
+
+	lvcreate --type raid10 -m 1 -i 2 -L 200T -n $lv1 $vg1 --nosync
+	check lv_field $vg1/$lv1 size "200.00t"
+	lvremove -ff $vg1
+
+	for segtype in raid4 raid5 raid6; do
+		lvcreate --type $segtype -i 3 -L 750T -n $lv1 $vg1 --nosync
+		check lv_field $vg1/$lv1 size "750.00t"
+		lvremove -ff $vg1
+	done
+
+	#
+	# Convert large linear to RAID1 (belong in different test script?)
+	#
+	lvcreate -L 200T -n $lv1 $vg1
+	# Need to deactivate or the up-convert will start sync'ing
+	lvchange -an $vg1/$lv1
+	lvconvert --type raid1 -m 1 $vg1/$lv1
+	check lv_field $vg1/$lv1 size "200.00t"
+	lvremove -ff $vg1
+
+	#
+	# Extending large RAID LV (belong in different script?)
+	#
+	lvcreate --type raid1 -m 1 -L 200T -n $lv1 $vg1 --nosync
+	check lv_field $vg1/$lv1 size "200.00t"
+	lvextend -L +200T $vg1/$lv1
+	check lv_field $vg1/$lv1 size "400.00t"
+	lvremove -ff $vg1
+
+	# bz837927 END
+fi
+
+lvremove -ff $vg