nerdexam
CompTIA

XK0-004 · Question #314

An administrator receives a USB drive and wants to make an exact copy of the disk before starting to work on it. One of the partitions on the USB drive was mounted as /dev/sdc1. Which of the…

The correct answer is A. dd if=/dev/sdc of=~/usb_copy.img bs=512. To create a complete forensic image of a USB drive, dd must reference the entire block device (/dev/sdc) rather than a single partition (/dev/sdc1), so the partition table and all partitions are captured.

System Management

Question

An administrator receives a USB drive and wants to make an exact copy of the disk before starting to work on it. One of the partitions on the USB drive was mounted as /dev/sdc1. Which of the following commands should the administrator use?

Options

  • Add if=/dev/sdc of=~/usb_copy.img bs=512
  • Bdd if=/dev/sdc1 of=~/usb_copy.img count=1024
  • Cdd if=/dev/sdc1 of=~/usb_copy.img bs=1024
  • Ddd of=/dev/sdc if=~/usb_copy.img bs=1M

How the community answered

(49 responses)
  • A
    76% (37)
  • B
    14% (7)
  • C
    6% (3)
  • D
    4% (2)

Why each option

To create a complete forensic image of a USB drive, dd must reference the entire block device (/dev/sdc) rather than a single partition (/dev/sdc1), so the partition table and all partitions are captured.

Add if=/dev/sdc of=~/usb_copy.img bs=512Correct

Using if=/dev/sdc targets the whole disk device including the MBR and partition table, producing a full sector-by-sector image of every partition on the drive. Setting bs=512 matches the standard disk sector size, ensuring accurate low-level copying without truncation or alignment issues.

Bdd if=/dev/sdc1 of=~/usb_copy.img count=1024

This copies only the single partition /dev/sdc1 and the count=1024 parameter artificially caps the copy at 1024 blocks, almost certainly missing data beyond that offset.

Cdd if=/dev/sdc1 of=~/usb_copy.img bs=1024

This also targets only the /dev/sdc1 partition rather than the full disk device, omitting the MBR, partition table, and any other partitions present on the drive.

Ddd of=/dev/sdc if=~/usb_copy.img bs=1M

This command has if and of reversed - it would write the local image file onto the USB drive, destroying the original data instead of preserving it.

Concept tested: Full disk imaging with dd using whole device path

Source: https://man7.org/linux/man-pages/man1/dd.1.html

Topics

#dd command#disk imaging#block copy#forensic copy

Community Discussion

No community discussion yet for this question.

Sign up to join the discussion
Full XK0-004 Practice