How to repair super blocks

1. The following commands are useful for checking raid status

pvdisplay; vgdisplay, lvdisplay; lvs, lvscan, mdadm

2. superblock information is backed up in many places, so don't worry it's corrupted. Check the article:

http://www.cnblogs.com/nathaninchina/articles/2748678.html

Basically:

(1) using the following command to find the error

sudo fsck.ext4 -v /dev/xxx

(2) using hte following command to find superblock backup

       mke2fs -n /dev/xxx

(3) using the following command to get backup:

       e2fsck -b block_number /dev/xxx