This is still very primitive support of drbd in lvm2.
Can we use some /sys information for this ?
Index: LVM2.2.02.58/lib/cache/lvmcache.c
================================================================================
--- LVM2.2.02.58/lib/cache/lvmcache.c
+++ LVM2.2.02.58/lib/cache/lvmcache.c
@@ -1222,6 +1222,14 @@
 						 dev_subsystem_name(existing->dev),
 						 dev_name(existing->dev));
 				return NULL;
+			} else if (MAJOR(existing->dev->dev) == drbd_major() &&
+					MAJOR(dev->dev) != drbd_major()) {
+				log_very_verbose("Ignoring duplicate PV %s on "
+						"%s - using drbd %s",
+						pvid, dev_name(dev),
+						dev_name(existing->dev));
+				return NULL;
+
 			} else if (dm_is_dm_major(MAJOR(existing->dev->dev)) &&
 				   !dm_is_dm_major(MAJOR(dev->dev))) {
 				log_very_verbose("Ignoring duplicate PV %s on "
@@ -1242,6 +1250,12 @@
 						 "using dm %s", pvid,
 						 dev_name(existing->dev),
 						 dev_name(dev));
+			else if (MAJOR(existing->dev->dev) != drbd_major() &&
+					MAJOR(dev->dev) == drbd_major())
+				log_very_verbose("Duplicate PV %s on %s - "
+						"using drbd %s", pvid,
+						dev_name(existing->dev),
+						dev_name(dev));
 			/* FIXME If both dm, check dependencies */
 			//else if (dm_is_dm_major(MAJOR(existing->dev->dev)) &&
 				 //dm_is_dm_major(MAJOR(dev->dev)))
--- LVM2.2.02.58/lib/filters/filter.c
+++ LVM2.2.02.58/lib/filters/filter.c
@@ -54,6 +54,13 @@
 	return _md_major;
 }
 
+/* FIXME: Should we consider filter out non-primary
+   drbd resource ?? */
+int drbd_major(void)
+{
+       return _drbd_major;
+}
+
 int blkext_major(void)
 {
 	return _blkext_major;