LVM on /dev/md127 fixes on CentOS5

lvm-fixes-on-centos5.md

LVM on /dev/md127 fixes on CentOS5

+---------------------------+
|        LVM Volumes        |
+---------------------------+
|     /dev/md1 (raid1)      |
+-------------+-------------+
|  /dev/sda2  |  /dev/sdb2  |
+-------------+-------------+

1. Boot into rescue mode (without mounting anything)
2. Scan raid devices and activate them.

  sh-3.2# mdadm --examine --scan >> /dev/mdadm.conf
  sh-3.2# mdadm --assemble --scan /dev/md0
  mdadm: /dev/md0 has been started with 2 drives.
  sh-3.2# mdadm --assemble --scan /dev/md1
  mdadm: /dev/md1 has been started with 2 drives.

3. Scan and activate LVM volumes

  sh-3.2# lvm vgscan -v
  sh-3.2# lvm vgchange -ay

4. Mount the volumes

  sh-3.2# mount /dev/VolGroup00/root /mnt/sysimage
  sh-3.2# mount /dev/VolGroup00/var /mnt/sysimage/var
  sh-3.2# mount /dev/md0 /mnt/sysimage/boot
  sh-3.2# mount --bind /dev /mnt/sysimage/dev
  sh-3.2# mount --bind /proc /mnt/sysimage/proc
  sh-3.2# mount --bind /sys /mnt/sysimage/sys

5. Correct GRUB

  sh-3.2# chroot /mnt/sysimage
  sh-3.2# grub-install /dev/sda

6. Exit and reboot

  sh-3.2# exit
  sh-3.2# exit