lvm-restore.bash

root@freetunes:/tmp# vgcfgrestore --file /etc/lvm/backup/lvm-raid lvm-raid
  Restored volume group lvm-raid
root@freetunes:/tmp# vgchange -ay
  1 logical volume(s) in volume group "lvm-raid" now active
root@freetunes:/tmp# lvs
  LV   VG       Attr   LSize Origin Snap%  Move Log Copy%  Convert
  lvm0 lvm-raid -wi-a- 5.46t 
root@freetunes:/tmp# e2fsck /dev/lvm-raid/lvm0 
e2fsck 1.41.11 (14-Mar-2010)
e2fsck: Superblock invalid, trying backup blocks...
e2fsck: Bad magic number in super-block while trying to open /dev/lvm-raid/lvm0

The superblock could not be read or does not describe a correct ext2
filesystem.  If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>
root@freetunes:/tmp# mdadm --fail /dev/md2 /dev/sda
mdadm: set /dev/sda faulty in /dev/md2
root@freetunes:/tmp# mount -a
root@freetunes:/mnt/tank# lvdisplay 
  --- Logical volume ---
  LV Name                /dev/lvm-raid/lvm0
  VG Name                lvm-raid
  LV UUID                D7Wj1A-wiJk-NxlM-IDdH-0uM4-aF1r-Fbpjjr
  LV Write Access        read/write
  LV Status              available
  # open                 1 # <<< YEY! VOLUME GOT MOUNTED!
  LV Size                5.46 TiB
  Current LE             22356
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     1536
  Block device           251:0

The reason why this wasn't working is because one of the disks has developed bad blocks. I ran badblocks with e2fsck and that fixed the problem, re-adding the disk back into the RAID6 array worked. LVM on the other hand wouldn't mount the logical volume due to those badblocks. I've temporarily removed the bad disk from the raid array and the lv mounted fine.

So how do I make LVM aware of he bad blocks?