Hello, I think I found a btrfs 0.19 problem when used in an lvm2 volume; btrfs is returning a st_dev stat from the mounted filesystem / that is different from the lvm2 blockdevice st_rdev stat in /dev/mapper/vg0-os0.
This btrfs behavior is different from ext4, where the st_dev and st_rdev stats match (http://pastebin.com/m64e90a8e or a summary below). Because of that, in grub2, 'grub-probe -t device / ' fails with ' grub-probe: error: cannot find a device for /. ' , and so update-grub2 fails causing cascading problems all around. Can anyone repeat this? Any ideas why this could be happening? Is this expected? Thanks, Marcus -- # uname -a Linux frog 2.6.31-9-generic #29-Ubuntu SMP Sun Aug 30 17:39:23 UTC 2009 i686 GNU/Linux # btrfs-show Label: none uuid: c5bffbe1-6968-4eee-a800-8346df56459a Total devices 1 FS bytes used 2.15GB devid 1 size 10.00GB used 10.00GB path /dev/mapper/vg0-os0 Btrfs Btrfs v0.19 # mount /dev/mapper/vg0-os0 on / type btrfs (rw,errors=remount-ro) /dev/mapper/vg0-os0 on /tmp/os0 type btrfs (rw) /dev/mapper/vg0-os1 on /tmp/os1 type ext4 (rw) stat.st_rdev for /dev/mapper/vg0-os0:64512 stat.st_rdev for /dev/mapper/vg0-os1:64513 stat.st_dev for /:16 stat.st_dev for /tmp/os0:16 stat.st_dev for /tmp/os1:64513 -- PS: Btw, in case someone else comes across this problem, a quick workaround for grub2 is to modify /usr/sbin/grub-mkconfig so that GRUB_DEVICE points directly to your btrfs lvm2 block device: # diff grub-mkconfig.orig grub-mkconfig 1122c122 < GRUB_DEVICE="`${grub_probe} --target=device /`" --- > GRUB_DEVICE="/dev/mapper/vg0-os0" -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
