fdisk and lsblk in Linux CLI - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this lsblk command?

You run the command lsblk -o NAME,SIZE,TYPE,MOUNTPOINT on a system with one disk sda of 100G and two partitions sda1 (50G, mounted on /) and sda2 (50G, not mounted). What is the output?

Linux CLI

lsblk -o NAME,SIZE,TYPE,MOUNTPOINT

A

NAME   SIZE TYPE MOUNTPOINT
sda    100G part 
sda1    50G disk /
sda2    50G part 

B

NAME   SIZE TYPE MOUNTPOINT
sda    100G disk /
sda1    50G part 
sda2    50G part 

C

NAME   SIZE TYPE MOUNTPOINT
sda    50G disk 
sda1    50G part /
sda2    50G part 

D

NAME   SIZE TYPE MOUNTPOINT
sda    100G disk 
sda1    50G part /
sda2    50G part 

💡 Hint

Remember that the disk is the whole device and partitions are parts of it. Only partitions can be mounted.

The disk sda is 100G and of type disk. Its partitions sda1 and sda2 are each 50G and of type part. Only sda1 is mounted on /. The disk itself is not mounted.

💻 Command Output

intermediate

What error does this fdisk command produce?

You run fdisk /dev/sdx on a system where /dev/sdx does not exist. What error message appears?

Linux CLI

fdisk /dev/sdx

A fdisk: permission denied

B fdisk: invalid partition table

C fdisk: cannot open /dev/sdx: No such file or directory

D fdisk: device is busy

💡 Hint

Check if the device file exists before running fdisk.

If the device file does not exist, fdisk cannot open it and shows 'No such file or directory'. Other errors occur in different situations.

📝 Syntax

advanced

Which fdisk command sequence creates a new primary partition?

You want to create a new primary partition on /dev/sdb using fdisk interactively. Which sequence of commands inside fdisk is correct?

Linux CLI

fdisk /dev/sdb
# Then enter commands interactively

A p (print), n (new partition), e (extended), 1 (partition number), w (write)

B n (new partition), p (primary), 1 (partition number), default start, default end, w (write)

C d (delete), n (new partition), l (logical), 1 (partition number), w (write)

D n (new partition), l (logical), 1 (partition number), default start, default end, q (quit)

💡 Hint

Primary partitions are created with 'p' after 'n'.

To create a primary partition, use 'n' to create new, then 'p' for primary, specify partition number, accept defaults for start and end, then 'w' to write changes.

🚀 Application

advanced

How to list only disks (not partitions) with lsblk?

You want to list only the disks (not their partitions) on your system using lsblk. Which command achieves this?

A lsblk -d

B lsblk -p

C lsblk -a

D lsblk -l

💡 Hint

The option '-d' shows only disks, no children.

The '-d' option in lsblk lists only the disks without showing partitions or other children.

🧠 Conceptual

expert

What is the effect of running 'fdisk -l' without root privileges?

You run fdisk -l as a normal user without sudo. What happens?

Linux CLI

fdisk -l

A It shows 'Permission denied' error and no output.

B It prompts for root password to continue.

C It lists only partitions on removable devices.

D It lists all partitions and disks without error.

💡 Hint

fdisk needs root to read disk info.

Without root privileges, fdisk cannot access disk info and shows a permission denied error.

Practice

1. What is the primary purpose of the fdisk command in Linux?

easy

A. To display the current directory contents

B. To create and modify disk partitions

C. To list running processes

D. To monitor network connections

Solution

1. Step 1: Understand the role of fdisk

   The fdisk command is used to create, delete, and modify disk partitions on Linux systems.

2. Step 2: Compare with other commands

   Other options like listing directories, processes, or network connections are unrelated to disk partitioning.

3. Final Answer:

   To create and modify disk partitions -> Option B

4. Quick Check:

   fdisk = disk partition tool [OK]

Hint: fdisk = fix disk partitions [OK]

Common Mistakes:

• Confusing fdisk with lsblk
• Thinking fdisk lists files
• Assuming fdisk monitors network

2. Which of the following is the correct syntax to list all block devices using lsblk?

easy

A. lsblk --all

B. lsblk -d

C. lsblk -l

D. lsblk -f

Solution

1. Step 1: Identify the option to list all devices

   The --all option with lsblk lists all devices, including empty ones.

2. Step 2: Check other options

   -d lists only whole disks (no partitions), -l lists in list format, -f shows filesystem info but not all devices.

3. Final Answer:

   lsblk --all -> Option A

4. Quick Check:

   lsblk --all = show all devices [OK]

Hint: --all shows everything in lsblk [OK]

Common Mistakes:

• Using -d instead of --all
• Confusing -l with --all
• Using -f to list devices

3. Given the command output below, what is the size of the partition /dev/sda1?

NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0  100G  0 disk 
sda1     8:1    0   50G  0 part /
sda2     8:2    0   50G  0 part /home

medium

A. 100G

B. 0G

C. 50G

D. 150G

Solution

1. Step 1: Read the lsblk output

   The line for /dev/sda1 shows a size of 50G under the SIZE column.

2. Step 2: Understand partition sizes

   The disk sda is 100G total, split into two partitions of 50G each.

3. Final Answer:

   50G -> Option C

4. Quick Check:

   /dev/sda1 size = 50G [OK]

Hint: Check SIZE column for partition size [OK]

Common Mistakes:

• Confusing disk size with partition size
• Adding partition sizes incorrectly
• Ignoring the SIZE column

4. You run fdisk /dev/sdb but get the error: cannot open /dev/sdb: Permission denied. What is the most likely cause?

medium

A. The disk /dev/sdb is formatted with ext4

B. The disk /dev/sdb is already mounted

C. The lsblk command is not installed

D. You forgot to run the command as root or with sudo

Solution

1. Step 1: Understand permission requirements

   Running fdisk on disks requires root privileges; without sudo or root, device access is denied.

2. Step 2: Check other options

   Disk being mounted or formatted does not cause 'Permission denied' error; missing lsblk is unrelated.

3. Final Answer:

   You forgot to run the command as root or with sudo -> Option D

4. Quick Check:

   fdisk needs root access [OK]

Hint: Use sudo with fdisk to access disks [OK]

Common Mistakes:

• Assuming mounted disk causes 'Permission denied'
• Thinking formatting affects fdisk detection
• Confusing fdisk errors with lsblk issues

5. You want to create a new partition on /dev/sdc using fdisk. After creating the partition, which command should you run to immediately see the updated partition layout in a tree view?

hard

A. lsblk /dev/sdc

B. fdisk -l /dev/sdc

C. mount /dev/sdc1 /mnt

D. df -h /dev/sdc

Solution

1. Step 1: Identify command to show partition tree

   lsblk displays block devices and partitions in a clear tree format, perfect for checking new partitions.

2. Step 2: Compare with other commands

   fdisk -l lists partitions but not in tree view; mount mounts partitions; df -h shows disk usage, not layout.

3. Final Answer:

   lsblk /dev/sdc -> Option A

4. Quick Check:

   lsblk shows partition tree [OK]

Hint: Use lsblk to view partitions visually [OK]

Common Mistakes:

• Using fdisk -l expecting tree view
• Trying to mount before checking partitions
• Using df to see partition layout