knoppix@Microknoppix:~$ su root root@Microknoppix:/home/knoppix# mkdir /tmp/n900 root@Microknoppix:/home/knoppix# mount -o ro,loop /media/sdc1/SystemBackups/20101109-backup-rootfs.img /tmp/n900 mount: you must specify the filesystem type root@Microknoppix:/home/knoppix#
root@Microknoppix:/home/knoppix# mount -o ro,loop /media/sdc1/SystemBackups/20101109-backup-optfs.img /tmp/n900 mount: wrong fs type, bad option, bad superblock on /dev/loop/0, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so