Restore the OS bootloader | Selectel Documentation

Restore the Linux bootloader in Rescue

The main boot loader for Linux operating systems is GRUB. In case of problems, you can restore the boot loader using LiveCD — boot into Rescue mode.

In the Live system, you must mount all partitions in a pre-created folder, e.g. /mntThe same way they were mounted in the main system.

To restore the bootloader:

Start the system from the LiveCD.
Open the CLI.
Print information about the partitions on the available disks:
```
fdisk -l
```
Locate the root partition where the system is installed. In the disk information you obtained in step 2, find the partition with type Linux filesystem. The root partition is located in /dev/sda*if the partitions are on a software RAID array — /dev/md* (the mount is performed to the appropriate array).
Suppose the primary system has a root partition /located in /dev/sda2and a section /bootlocated in /dev/sda1. Mount the partitions in /mnt:
```
mount /dev/sda2 /mnt/
mount /dev/sda1 /mnt/boot
```
If you are using a UEFI bootloader, mount the EFI partition:
```
mount /dev/sda3 /mnt/boot/efi
```
Specify /dev/sda3 — EFI partition.

With the command cat /mnt/etc/fstab you can see the mount point in the host OS, as well as the UUID of the disk and map it to the UUID of the disk in the Live image.

Mount the directories /sys, /proc, /dev:

mount --bind /sys /mnt/sys
mount --bind /proc /mnt/proc
mount --bind /dev /mnt/dev