Sample menu:

Question: Why is the partition table I see for the disk image different from that stated in the handout?

Answer: The partition table listed in the handout does not include an entry for the second extended partition contained in the disk image. An extended partition looks like a linked list. In each extended boot record (EBR), its first entry describes an information about a current partition and the second entry describes a way to find the next extended partition if available.

Complete partition table for disk image provided

Partition # Type Start Length
1 0x83 (ext2) 63 48132
2 0x0 (unused) 0 0
3 0x83 (ext2) 48195 48195
4 0x5 (extended) 96390 64260
5 0x82 (swap) 96453 16002
- 0x5 (extended) 112455 48195
6 0x83 (ext2) 112518 48132


Question: How to assign a partition number?

Answer: To make sure the assignment consistent with our grader tool, all primary partitions in the master boot record are numbered 1-4 whether it is empty or extended. Then, all logical partitions are numbered starting from 5 and all non-primary extended partitions are excluded.


Question: Where can I find more information about MBR, EBR, EXT2?

Answer: I recommend you to take a look at the following pages:,,


Question: How to mount disk image as a normal partition under Linux?


If you want to use disk image for debugging, you can do the following steps:

1. extract target partition from the disk image: Take the disk image we provided as an example. In part1, you can find out the starting sector of partition 2 and number of sectors it has. Then extract this partition using the following command:

dd if=disk of=hda.img bs=512 skip=[starting sector] count=[#sectors]

2. Mount the extracted image in a directory (e.g. /mnt/test/)

mount -o loop hda.img /mnt/test/

Then you can access /mnt/test as a normal partition in Linux.