Why disk management prevents outages in Linux CLI - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to list all disk partitions on a Linux system.

Linux CLI

lsblk [1]

Drag options to blanks, or click blank then click option'

A-l

B-f

C-m

D-a

Attempts:

3 left

💡 Hint

Common Mistakes

Using options that show tree format instead of list.

Using options that filter output too much.

The lsblk -l command lists all block devices in a list format, showing partitions clearly.

2fill in blank

medium

Complete the command to check disk usage of the root directory.

Linux CLI

df [1] /

Drag options to blanks, or click blank then click option'

A-i

B-a

C-T

D-h

Attempts:

3 left

💡 Hint

Common Mistakes

Using -a which shows all filesystems, not just root.

Using -T which shows filesystem type instead of size.

The df -h / command shows disk usage of the root directory in a human-readable format.

3fill in blank

hard

Fix the error in the command to create a new partition on /dev/sdb using fdisk.

Linux CLI

echo -e 'n\np\n[1]\n\n\nw' | fdisk /dev/sdb

Drag options to blanks, or click blank then click option'

Ap

Bd

C1

Dq

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'p' which prints the partition table instead of creating a new partition.

Using 'd' which deletes a partition.

The n command creates a new partition, and 1 selects partition number 1.

4fill in blank

hard

Fill both blanks to create a mount point and mount the partition /dev/sdb1 to it.

Linux CLI

mkdir [1]
mount [2] /mnt/data

Drag options to blanks, or click blank then click option'

A/mnt/data

B/dev/sdb1

C/mnt/backup

D/dev/sda1

Attempts:

3 left

💡 Hint

Common Mistakes

Mounting the wrong device or to a directory that does not exist.

Creating a directory but mounting a different path.

You create the directory /mnt/data and mount the device /dev/sdb1 there.

5fill in blank

hard

Fill all three blanks to add a new entry to /etc/fstab for automatic mounting of /dev/sdb1 to /mnt/data with ext4 filesystem and default options.

Linux CLI

echo '[1] [2] [3] defaults 0 2' | sudo tee -a /etc/fstab

Drag options to blanks, or click blank then click option'

A/dev/sdb1

B/mnt/data

Cext4

D/mnt/backup

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong device or mount point paths.

Using incorrect filesystem type.

The fstab entry format is: device, mount point, filesystem type, options, dump, pass.

Here, device is /dev/sdb1, mount point is /mnt/data, and filesystem type is ext4.

Practice

1. Why is regular disk management important to prevent system outages?

easy

A. It helps avoid running out of disk space and system crashes.

B. It makes the computer run faster by increasing CPU speed.

C. It changes the screen resolution automatically.

D. It updates the operating system without user permission.

Solution

1. Step 1: Understand disk space impact

   Running out of disk space can cause programs to fail and the system to crash.

2. Step 2: Recognize disk management role

   Disk management monitors and frees space to keep the system stable.

3. Final Answer:

   It helps avoid running out of disk space and system crashes. -> Option A

4. Quick Check:

   Disk space management prevents crashes = B [OK]

Hint: Disk space full? System crashes. Manage disks to prevent that. [OK]

Common Mistakes:

• Confusing disk management with CPU or display settings
• Thinking disk management updates software automatically
• Ignoring disk space as a cause of outages

2. Which Linux command correctly shows disk usage of all mounted filesystems?

easy

A. top

B. ls -l

C. df -h

D. ps aux

Solution

1. Step 1: Identify command purpose

   The df command reports disk space usage; -h makes it human-readable.

2. Step 2: Compare other commands

   ls -l lists files, top shows processes, ps aux lists running processes.

3. Final Answer:

   df -h -> Option C

4. Quick Check:

   Disk usage command = df -h [OK]

Hint: Use df -h to check disk space in human-friendly format. [OK]

Common Mistakes:

• Using ls or ps commands to check disk space
• Forgetting the -h option for readable sizes
• Confusing process commands with disk commands

3. What is the output of the command lsblk on a Linux system?

medium

A. Prints the contents of the current directory.

B. Shows current CPU usage statistics.

C. Displays network interface details.

D. Lists all block devices like disks and partitions.

Solution

1. Step 1: Understand lsblk command

   lsblk lists block devices such as hard drives and their partitions.

2. Step 2: Eliminate unrelated outputs

   CPU stats, network info, and directory contents are shown by other commands like top, ifconfig, and ls.

3. Final Answer:

   Lists all block devices like disks and partitions. -> Option D

4. Quick Check:

   lsblk shows disks and partitions = A [OK]

Hint: lsblk lists disks and partitions clearly. [OK]

Common Mistakes:

• Confusing lsblk with commands showing CPU or network info
• Expecting file listings instead of device info
• Assuming lsblk modifies disks instead of listing

4. You run df -h and see 100% usage on /dev/sda1. What is the best immediate action to prevent outages?

medium

A. Change the screen resolution to reduce load.

B. Delete unnecessary files or move data to free space.

C. Run top to kill CPU-heavy processes.

D. Restart the computer immediately without checking disk.

Solution

1. Step 1: Analyze disk full problem

   100% disk usage means no free space, risking crashes and data loss.

2. Step 2: Choose proper action

   Deleting or moving files frees space immediately; restarting or changing screen resolution won't fix disk space.

3. Final Answer:

   Delete unnecessary files or move data to free space. -> Option B

4. Quick Check:

   Free disk space to prevent outages = D [OK]

Hint: Free disk space first to avoid crashes. [OK]

Common Mistakes:

• Restarting without fixing disk space
• Confusing CPU load with disk space issues
• Trying unrelated fixes like screen changes

5. You want to automate disk checks to prevent outages. Which script snippet correctly checks disk usage and warns if usage exceeds 90% on /dev/sda1?

hard

A. usage=$(df /dev/sda1 | tail -1 | awk '{print $5}' | sed 's/%//'); if [ "$usage" -gt 90 ]; then echo "Warning: Disk usage above 90%"; fi

B. usage=$(top -b | grep sda1); if [ "$usage" -gt 90 ]; then echo "Warning"; fi

C. usage=$(lsblk /dev/sda1); if [ "$usage" -gt 90 ]; then echo "Warning"; fi

D. usage=$(ps aux | grep sda1); if [ "$usage" -gt 90 ]; then echo "Warning"; fi

Solution

1. Step 1: Extract disk usage percentage correctly

   The command df /dev/sda1 shows disk usage; awk '{print $5}' gets the percent; sed 's/%//' removes the percent sign.

2. Step 2: Use conditional to warn if usage > 90%

   The if statement compares usage as a number and prints a warning if above 90.

3. Final Answer:

   usage=$(df /dev/sda1 | tail -1 | awk '{print $5}' | sed 's/%//'); if [ "$usage" -gt 90 ]; then echo "Warning: Disk usage above 90%"; fi -> Option A

4. Quick Check:

   Correct disk usage check and warning = A [OK]

Hint: Use df and awk to get usage, then compare with if. [OK]

Common Mistakes:

• Using unrelated commands like top or ps for disk usage
• Not removing % sign before numeric comparison
• Incorrect syntax in if statement