user@ChrUbuntu:~/backups$ sudo fdisk -lu sdcard.img
[sudo] password for user:

Disk sdcard.img: 15.9 GB, 15931539456 bytes
255 heads, 63 sectors/track, 1936 cylinders, total 31116288 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
Disk identifier: 0x00017b69

     Device Boot      Start         End      Blocks   Id  System
sdcard.img1            8192      122879       57344    c  W95 FAT32 (LBA)
sdcard.img2          122880    31115263    15496192   83  Linux
user@ChrUbuntu:~/backups$ sudo mount -o loop,offset=$((122880 * 512)) disk.img
mount: can't find disk.img in /etc/fstab or /etc/mtab
user@ChrUbuntu:~/backups$ mkdir mount
user@ChrUbuntu:~/backups$ sudo mount -o loop,offset=$((122880 * 512)) sdcard.img mount/
user@ChrUbuntu:~/backups$ ls mount/
bin  boot  boot.bak  dev  etc  home  lib  lost+found  media  mnt  opt  proc  root  run  sbin  selinux  srv  sys  tmp  usr  var
user@ChrUbuntu:~/backups$