- A
The command preserves the partition table of the source disk.
Why wrong: The partition table is preserved because the entire disk is imaged, but the command itself does not specifically ensure that.
- B
The command automatically computes MD5 hash of the output file.
Why wrong: dd does not compute hashes; a separate tool like md5sum must be used.
- C
If a read error occurs, dd will pad the output with zeros and continue.
The conv=noerror,sync option causes dd to fill read errors with zeros and continue imaging.
- D
The block size (bs=4k) is appropriate for imaging a disk to reduce overhead.
A 4k block size is commonly used for efficient disk imaging.
- E
The output file will be compressed to save storage space.
Why wrong: dd does not compress output; compression requires piping through gzip or similar.
CHFI Evidence Acquisition and Duplication Practice Question
This CHFI practice question tests your understanding of evidence acquisition and duplication. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
During acquisition of a live Linux server, the forensic examiner runs the following command: # dd if=/dev/sda of=/mnt/evidence/disk.dd conv=noerror,sync bs=4k. Which TWO statements are true about this acquisition?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
If a read error occurs, dd will pad the output with zeros and continue.
Option C is correct because the `conv=noerror,sync` parameter tells `dd` to continue reading even if a read error occurs, and to pad the output block with zeros to maintain the correct offset and size. This ensures the image remains usable for analysis despite bad sectors on the source disk.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The command preserves the partition table of the source disk.
Why it's wrong here
The partition table is preserved because the entire disk is imaged, but the command itself does not specifically ensure that.
- ✗
The command automatically computes MD5 hash of the output file.
Why it's wrong here
dd does not compute hashes; a separate tool like md5sum must be used.
- ✓
If a read error occurs, dd will pad the output with zeros and continue.
Why this is correct
The conv=noerror,sync option causes dd to fill read errors with zeros and continue imaging.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
The block size (bs=4k) is appropriate for imaging a disk to reduce overhead.
Why this is correct
A 4k block size is commonly used for efficient disk imaging.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The output file will be compressed to save storage space.
Why it's wrong here
dd does not compress output; compression requires piping through gzip or similar.
Common exam traps
Common exam trap: answer the scenario, not the keyword
EC-Council often tests the misconception that `dd` automatically hashes or compresses output, when in fact it is a raw copy tool and those functions require separate commands or piping.
Trap categories for this question
Similar concept trap
dd does not compress output; compression requires piping through gzip or similar.
Command / output trap
The partition table is preserved because the entire disk is imaged, but the command itself does not specifically ensure that.
Detailed technical explanation
How to think about this question
The `conv=noerror,sync` combination is critical for forensic imaging of failing drives: `noerror` allows `dd` to skip bad blocks, while `sync` pads the skipped block with null bytes (zeros) so the total byte count matches the source, preserving the logical layout. The `bs=4k` block size aligns with typical filesystem block sizes (e.g., ext4 default is 4 KiB), reducing the number of I/O operations and overhead compared to smaller block sizes like 512 bytes, which is especially important for large disks.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the CHFI exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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FAQ
Questions learners often ask
What does this CHFI question test?
Evidence Acquisition and Duplication — This question tests Evidence Acquisition and Duplication — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: If a read error occurs, dd will pad the output with zeros and continue. — Option C is correct because the `conv=noerror,sync` parameter tells `dd` to continue reading even if a read error occurs, and to pad the output block with zeros to maintain the correct offset and size. This ensures the image remains usable for analysis despite bad sectors on the source disk.
What should I do if I get this CHFI question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 30, 2026
This CHFI practice question is part of Courseiva's free EC-Council certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CHFI exam.
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