Linux GRUB Rescue — Unknown Filesystem Fix
Criticallinux boot
Overview
Fix "GRUB rescue>" prompt. GRUB cannot find its configuration files or the boot partition.
Key Details
- Error: error: unknown filesystem / GRUB rescue>
- Category: Linux Boot Error
- GRUB bootloader is broken
- System cannot boot into Linux
Common Causes
- Partition table changed (Windows update, resize)
- GRUB files deleted or corrupted
- Dual-boot Windows update overwrote bootloader
- Drive order changed in BIOS
Steps
- 1Find correct partition: ls (hd0,gpt1)/
- 2Set root: set root=(hd0,gpt2)
- 3Load normal mode: insmod normal → normal
- 4After booting: sudo grub-install /dev/sda && sudo update-grub
- 5Use a Live USB to chroot and repair GRUB
Tags
linuxlinux-bootlinux grub rescueubuntuterminal
More in Linux Boot
Frequently Asked Questions
Often yes — Windows updates can overwrite the EFI boot entry.