--- genkernel-3.4.10.906.orig/defaults/linuxrc
+++ genkernel-3.4.10.906/defaults/linuxrc
@@ -229,6 +229,9 @@
 # Start device manager
 start_dev_mgr
 
+# start BTRFS volume detection
+[ -x /sbin/btrfsctl ] && /sbin/btrfsctl -a
+
 # Setup md device nodes if they dont exist
 setup_md_device