grub-probe

probe device and filesystem information for GRUB

TLDR

Get GRUB filesystem module for a path

$ sudo grub-probe -t fs /boot/grub

Get the system device containing a path

$ sudo grub-probe -t device /boot/grub

Get the underlying disk for a system device

$ sudo grub-probe -t disk /dev/sdX -d

Get filesystem UUID

$ sudo grub-probe -t fs_uuid /boot/grub

Get filesystem label

$ sudo grub-probe -t fs_label /boot/grub

Get MBR partition type code

$ sudo grub-probe -t msdos_parttype /dev/sdX

Get the partition map type

$ sudo grub-probe -t partmap /boot/grub

Probe using a custom device map

$ sudo grub-probe -t fs /boot/grub -m [path/to/custom_device.map]

SYNOPSIS

grub-probe [options] -t target path|device

grub-probe extracts device and filesystem information in GRUB's naming format. It is primarily used internally by GRUB tools but is useful for debugging boot configuration.Target types include fs (filesystem module), device (system device path), disk (system disk path), drive (GRUB drive name like hd0), fs_uuid (filesystem UUID), fs_label (filesystem label), partmap (partition map type), partuuid (partition UUID), abstraction (abstraction module like lvm), cryptodisk_uuid, msdos_parttype, gpt_parttype, and various boot hint targets.This tool bridges Linux device names to GRUB's naming conventions, which is essential for generating correct boot configurations.

PARAMETERS

-t, --target TARGET

Information to probe: fs, fsuuid, fslabel, device, disk, drive, partmap, partuuid, abstraction, cryptodiskuuid, msdosparttype, gptparttype, hintsstring, zero_check (default: fs)

-d, --device

Treat argument as a system device, not a path

-m, --device-map FILE

Use custom device map file (default: /boot/grub/device.map)

-0

Separate items in output using ASCII NUL characters

-v, --verbose

Enable verbose output (pass twice for debug printing)

INSTALL

sudo apt install grub-common

sudo pacman -S grub

sudo apk add grub

CAVEATS

Requires root privileges for most operations. Device mapping can change between boots, especially with removable media. GRUB drive naming may differ from Linux device names.

HISTORY

grub-probe is part of GRUB 2's toolset, providing the device detection logic used by grub-install and grub-mkconfig. It replaced simpler detection methods used in GRUB Legacy.