Digital Forensic Certification Practice Exam

What part of the MBR structure is required by BIOS during booting and holds only 2 bytes of data?

1. Disk signature

2. Bootloader

3. Partition table

4. MBR checksum

The correct answer is: Disk signature

The part of the Master Boot Record (MBR) structure that is required by the BIOS during the booting process and holds only 2 bytes of data is the disk signature. The disk signature is a unique identifier assigned to a disk drive, which allows the BIOS to recognize and differentiate between multiple disks connected to the system. This signature is essential during the boot process because it helps the BIOS locate the correct drive to boot from and also assists in identifying partitions on that disk. In contrast, the bootloader, which is responsible for loading the operating system, encompasses far more than just 2 bytes of data and contains the necessary code to initiate the OS. The partition table, while also integral to the operation of the MBR, contains entries that describe the partitions on the disk, which takes up more space than just 2 bytes. Lastly, the MBR checksum serves to verify the integrity of the MBR structure itself, but it is not the component that the BIOS directly requires for the boot process in the same manner as the disk signature. Hence, the disk signature is the critical 2-byte data segment that fulfills this specific role during booting.