mount disk image files / loop / kpartx

apt-get install kpartx

Show partitions

• fdisk -l myserver.root.img

List device mappings that would be created

• kpartx -l myserver.root.img

Create mappings / create dev for image

• kpartx -av myserver.root.img
  • add map loop0p1 (252:1): 0 310378496 linear 7:0 2048
    add map loop0p2 (252:2): 0 6289408 linear 7:0 310380544
  • the device is
    • /dev/loop0
  • the partions are
    • /dev/mapper/loop0p1
      /dev/mapper/loop0p1

Mount a partition

• mount -o loop /dev/mapper/loop0p1 /mnt/

Find out what image file a loop belongs to

• losetup --list
  • /dev/loop0         0      0         0  0 /path/to/myserver.root.img

• cat /sys/class/block/loop0/loop/backing_file
  
  • /path/to/myserver.root.img

If you want to get the exact loop device for a script you can do

• losetup --list | grep "/path/to/myserver.root.img" | cut -d ' ' -f1
  • /dev/loop0

Remove mapping

• kpartx -d myserver.root.img