Aqui está um script que eu uso para montar partições de arquivos de imagem. Veja os comentários no início do script para informações de uso.
#!/bin/bash
# mount_image, a program that mounts a specific partition from a RAW
# disk image file, such as a full-disk dd copy or a file used by QEMU.
# Note that compressed and other space-saving formats (qcaw2, etc.)
# will NOT work!
# Use:
# mount_image image_file partition_number mount_point
#
# For instance,
#
# mount_image image.raw 2 /mnt/shared
#
# mounts partition 2 from image.raw at /mnt/shared.
# This program relies on my GPT fdisk (gdisk) program to help identify
# partitions. I could have used regular fdisk, but this would have
# limited the program to working with MBR-formatted disks. With gdisk,
# both MBR- and GPT-formatted disks will work.
gdisk -l $1 > /tmp/mount_image.tmp
let StartSector='egrep "^ $2|^ $2" /tmp/mount_image.tmp | fmt -u -s | sed -e 's/^[ \t]*//' | head -1 | cut -d " " -f 2'
let StartByte=($StartSector*512)
echo "Mounting partition $2, which begins at sector $StartSector"
mount -o loop,offset=$StartByte $1 $3
rm /tmp/mount_image.tmp