failed to restore root filesystem from dump backup

I'm currently testing a backup/restore of RHEL 6.4 OS via the "dump" and "restore" on testing environment, and I do know that RHEL 6.4 seemed too outdated in nowadays. Butsome enterprises are still using such version of RHEL to load their services. **Here's the scenario**: to backup the system and critical programs in case of host crash/failure event. * The test RHEL 6.4 host for backup utilizes windows Hyper-V VM as infrastrucure and the OS root is installed on LVM logical volume. * In order to backup the system, I placed system into single user mode and used command to backup the root filesystem

-shell
    dump -0uf //mybackup.dump /

* The dump showed "DUMP IS DONE" on screen and the dump file was created with size about 2.2GB therefore I believed that the backup was successful. In order to simulate host crash event, I reinstalled the RHEL 6.4 system utilizing LVM logical volume and boot the system into single user mode before restoration. However, after restoring root filesystem using

-shell
restore -rf //mybackup.dump

The screen showed kernel panic and some other errors, and hung eventually. I retried several times but always failed. Can anyone give me some hints why the restoration can't be completed?