I managed to fix it. Here are the steps:
1. Boot into Ubuntu – Rescue mode
2. Do not mount the root file system
3. lvm vgscan
4. Deactivate the volume group
- a. vgchange –a n VOLUME-GROUP-NAME
b. lvm lvscan
5. Rename the volume group
- a. lvm vgrename OLD-NAME NEW-NAME
b. lvm lvscan
c. It will be activated automatically, if not type vgchange –a y NEW-VOLUME-GROUP-NAME
6. Exit and choose different file system
- a. select ROOT file system
7. Backup /etc/fstab file
- a. cp –p /etc/fstab /etc/fstab.old
8. Edit /etc/fstab and replace OLD-NAME
- a. vi /etc/fstab
b. :%s/OLD--NAME/NEW-NAME/g
9. If /boot is empty, then mount /dev/sda1
10. Install grub and update it.
- a. grub-install /dev/sda
b. update-grub
11. Exit and reboot the server.
12. Boot from hard disk.