kpartx

Add partition mappings and print created mappings

$ kpartx -av [whole_disk.img]

$ kpartx -d [whole_disk.img]

$ kpartx -l [whole_disk.img]

kpartx [options] [device|file]

-a, --add
    Add partition mappings to /dev/mapper/

-d, --delete
    Delete partition mappings

-l, --list
    List partition table entries without mapping

-u, --update
    Update existing partition mappings

-p, --part-postfix prefix
    Set partition name postfix (default: p)

-g, --gpt
    Detect only GPT partition tables

-r, --dos
    Detect only DOS/MBR tables (default)

-v, --verbose
    Enable verbose output

kpartx is a Linux utility for managing device-mapper mappings of partitions from block devices or disk image files. It reads partition tables (DOS/MBR or GPT) and creates corresponding device nodes in /dev/mapper/, such as /dev/mapper/loop0p1 for the first partition on /dev/loop0.

This is essential for accessing individual partitions in whole-disk images without manual loop device setup. Common workflows involve pairing with losetup: set up a loop device for an image, run kpartx -a to map partitions, mount them, then kpartx -d to clean up.

Key features include listing partitions without mapping (-l), updating existing maps (-u), and custom naming prefixes (-p). It supports verbose output for troubleshooting. Primarily used in forensics, virtualization, live CDs, and multipath storage environments where direct partition access is needed.

kpartx relies on the device-mapper kernel module and does not handle LVM, RAID, or encrypted volumes directly—use specialized tools like cryptsetup or mdadm for those. Operations are safe for read-only images but require caution with live devices to avoid data corruption.

Requires root privileges and device-mapper kernel module. Does not unmount filesystems or handle LVM/RAID/encryption. Risk of naming conflicts on live devices; always umount before -d.

losetup -f image.img (e.g., /dev/loop0)
kpartx -a /dev/loop0 (maps partitions)
mount /dev/mapper/loop0p1 /mnt
kpartx -d /dev/loop0
losetup -d /dev/loop0

kpartx -l image.img (dry-run list)

Introduced around 2004-2005 in multipath-tools (device-mapper-multipath) for handling partitions on mapped devices; evolved for broad use with loop devices and images in distros like Debian/Ubuntu.

losetup(8), dmsetup(8), partprobe(8), fdisk(8), gdisk(8)