Boot disks are often used for system recovery in case of failure. Common use cases include:
System Rescue: Booting from a Live CD/USB allows you to access a minimal environment to fix problems on the system’s disk (e.g., corrupted filesystems, broken bootloaders).
Example:
Use a rescue mode from a Linux bootable USB.
Repair a corrupted filesystem using fsck
:
sudo fsck /dev/sda1
Reinstalling the Bootloader: If the bootloader (GRUB) is corrupted, you can boot from a Live USB, then reinstall GRUB:
sudo mount /dev/sda1 /mnt
sudo mount --bind /dev /mnt/dev
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys
sudo chroot /mnt
grub-install /dev/sda
update-grub
exit
sudo umount /mnt
Backing Up Data: Before attempting repairs, you can boot from a Live USB and use tools like rsync
to back up data from the mounted partitions to an external drive.