Bug#612402: UUID may be needed for btrfs RAID (patch)

[Daniel Pocock]

I discovered another issue related to this

Basically, for btrfs RAID, where the RAID is formed from logical
volumes, scripts/local-top/lvm2 only calls

   lvchange -ay something

for the first LV in the RAID.

E.g. if I have root=/dev/mapper/vg00-lv0 then my other LV,
/dev/mapper/vg00-lv1 is never activated.

This means that `btrfs dev scan' fails to find the array.

One way to solve this issue would be listing the btrfs filesystem's UUID as

     root=UUID=xxxxxx

Here is a patch that solves the original issue and provides a way to
boot btrfs RAID1, I tested this on a fresh installed of wheezy from
beta1 DVD:




--- scripts/local-top/lvm2.orig	2012-08-29 14:37:04.672826476 +0200
+++ scripts/local-top/lvm2	2012-08-29 14:38:04.118536514 +0200
@@ -35,6 +35,10 @@
 		lvm vgchange -aly --ignorelockingfailure
 		exit 0
 		;;
+	/dev/disk/by-uuid/*)
+		lvm vgchange -aly --ignorelockingfailure
+		exit 0
+		;;
 	esac

 	# Make sure that we have a d-m path