Linux GRUB Error Unknown Filesystem

Overview

Linux GRUB "error: unknown filesystem" means the bootloader cannot read the filesystem containing the kernel and boot files.

Key Details

• GRUB drops to rescue> or grub> prompt
• Cannot find /boot partition or its contents
• Common after resizing partitions or dual-boot changes
• System will not boot until GRUB is repaired

Common Causes

• Partition UUIDs changed after resize or move
• GRUB configuration references wrong partition
• Boot partition filesystem corrupted
• Partition table modified by another OS

Steps

1. 1From grub rescue>: ls to list partitions, then ls (hdX,Y)/ to find boot
2. 2Set root: set root=(hdX,Y) and load: insmod normal, then normal
3. 3Boot from live USB and reinstall GRUB: grub-install /dev/sdX
4. 4Update GRUB config: update-grub

Tags

More in Boot

Frequently Asked Questions