When I did the RAID 10 test, I didn’t add the “UUID” information into /etc/mdadm.conf file initially. After I reboot the system, it was unable to boot.
I inputted the password and entered the maintenance mode. I tried to delete the line I had added from the /etc/fstab file, but the file is in real-only mode and I could not to modify it. After searched the solution in the internet, I did the following four steps. The problem had been solved.
1. Check the filesystems.
(Repair filesystem) 1 # fsck –a
fsck.ext4: No such file or directory while trying to open /dev/datavg/datalv
2. Remount the root file system and make it writable.
(Repair filesystem) 2 # mount –o remount,rw /
EXT4 FS on dm-0, internal journal on dm-0:8
3. Edit the /etc/fstab file, delete the line I had added, save and quit.
(Repair filesystem) 3 # vi /etc/fstab
4. Reboot the system.
(Repair filesystem) 4 # reboot