How to check boot path (partition) in Linux

How do I identify the boot device or boot path in Linux operating system?

You can find the boot device or boot path in Linux using any one of the following command:

How to use lsblk to display boot partition

Simply type the following command:
$ lsblk
OR
$ lsblk -l
OR
$ lsblk /dev/sda
Sample outputs:

Fig.01: Linux lsblk command show boot device name

The following line (/boot or BOOT) indicates the information about my boot device on Linux:

|-sda1   8:1    1   243M  0 part /boot

How to use fdisk command to display boot partition

Type the following command:
# fdisk -l # fdisk -l /dev/sda
Sample outputs:

Fig.02: Linux fdisk command show boot device name

You will find this information at the line starting with Device Boot and marked with *. In this example output, my /dev/sda1 is boot device or partition on Linux.

How to use sfdisk command to display boot partition

Type the following command:
# sfdisk -l # sfdisk -l /dev/sda
Sample outputs:

Fig.03: Linux use sfdisk command show boot device name

A note about multiple devices (HDD/RAID)

If you’ve multiple hard drives or Linux software raid, it is going to be hard to find out this information. Consider the following:
# fdisk -l | grep '^Disk /dev'
Sample outputs:

Disk /dev/sdd: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Disk /dev/sdc: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Disk /dev/sde: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors
Disk /dev/md2: 1.5 TiB, 1610636328960 bytes, 3145774080 sectors
Disk /dev/md1: 1.5 GiB, 1602748416 bytes, 3130368 sectors
Disk /dev/md0: 120 GiB, 128877330432 bytes, 251713536 sectors
Disk /dev/md3: 600 GiB, 644257677312 bytes, 1258315776 sectors
Disk /dev/sdf: 492 MiB, 515899392 bytes, 1007616 sectors
Disk /dev/mapper/securebackup: 600 GiB, 644256104448 bytes, 1258312704 sectors
Disk /dev/mapper/cryptvg-mybackup: 600 GiB, 644253483008 bytes, 1258307584 sectors

I’ve multiple disk installed and Linux software RAID devices too. Here is a quick way to find out boot path or partition:

fdisk -l | grep '^/dev/[a-z]*[0-9]' | awk '$2 == "*"'
## OR ##
fdisk -l | grep '^/dev/[a-z]*[0-9]' | awk '$2 == "*" { print $0}'

Sample outputs:

/dev/sdf1  *       62 1006879 1006818 491.6M 83 Linux

/dev/sdf1 is my boot path and to verify the same:
# fdisk -l /dev/sdf
Sample outputs:

 
Disk /dev/sdf: 492 MiB, 515899392 bytes, 1007616 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x000e31b0
 
Device     Boot Start     End Sectors   Size Id Type
/dev/sdf1  *       62 1006879 1006818 491.6M 83 Linux

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

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6 comment

my test on debian, that lsblk -l doesn’t show any boot information, there is no mount point at /boot

John Donovan says:
January 8, 2016 at 2:56 pm
You don’t provide how you ran the command, but I think you ran it as your regular user account; use sudo.

nyu@ What about fdisk command?

If you don’t have a “/boot” mount point, then you haven’t set up a separate boot partition. You will have booted directly off the root file system, “/”, then.

you can use “fdisk -l | awk ‘/^\/dev\/[a-z]*[0-9]/ && $2 ~ /\*/'” but from what I know, Linux can boots with boot flags on boot partition.

In my system the command
sudo fdisk -l
produces the output

Disk /dev/nvme0n1: 477 GiB, 512110190592 bytes, 1000215216 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: A5F89FA8-01CC-48F0-890F-5B4033C8EAC6

Device             Start        End   Sectors   Size Type
/dev/nvme0n1p1      2048    1026047   1024000   500M EFI System
/dev/nvme0n1p2   1026048    1288191    262144   128M Microsoft reserved
/dev/nvme0n1p3   1288192  200968191 199680000  95.2G Microsoft basic data
/dev/nvme0n1p4 979740672  980662271    921600   450M Windows recovery environment
/dev/nvme0n1p5 980662272 1000214527  19552256   9.3G Windows recovery environment
/dev/nvme0n1p6 200968192  471980031 271011840 129.2G Linux filesystem

Partition table entries are not in disk order.


Disk /dev/sda: 119.2 GiB, 128035676160 bytes, 250069680 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 33553920 bytes
Disklabel type: dos
Disk identifier: 0x1fc4ae9b

Device     Boot Start       End   Sectors   Size Id Type
/dev/sda1  *     2048 250066943 250064896 119.2G 83 Linux

It falsely reports /dev/sda1 as boot; it is an external not bootable hard disk (formatted as ext4).

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