Linux 07 Failure Recovery

1. Simulate the repair of MBR sector after being destroyed.

MBR Failure Recovery:

1. Backup

Add a hard drive

To start the operating system:

To add a hard drive:

To format a partition:

Mount:

Do backup:

Destroying MBR

Restart the system:

Shutting down a virtual machine

Set up disc boot

Rescue mode:

Mount the hard drive to the/mnt/sysimage

Start recovery:

Start successfully!

2. Grub Boot Failure

simulates the repair of a master boot in MBR after Grub is destroyed. (one is to boot by command, and the other is to restore the backup file through rescue mode)

2.1 Modifying Grub.conf

Comment Line

Boot system

Restart normal entry system.

2.2 Missing conditions

Make a backup first:

Then delete:

After reboot, go directly to:

Through rescue mode:

Restart:

After rebooting, it can start normally.

Very slow start-up time because the Getenforce is in the open state

3. Set a scheduled task, restart the system every minute, and see how to cancel the scheduled task

It's restarted in 1 minutes.

Start Rescue mode:

Task canceled after reboot