File system types (ext4, xfs) in Linux CLI - Mini Project: Build & Apply

Check and Compare File System Types

📖 Scenario: You are managing a Linux server and want to check the file system types of different mounted drives. Knowing the file system type helps you understand how data is stored and managed on each drive.

🎯 Goal: Build a simple script that lists mounted drives and shows their file system types, then filters to show only drives with ext4 or xfs file systems.

📋 What You'll Learn

Create a variable with a sample list of mounted drives and their file system types.

Add a variable to specify which file system types to filter (ext4 and xfs).

Use a loop or comprehension to select only drives with the specified file system types.

Print the filtered list showing drive names and their file system types.

💡 Why This Matters

🌍 Real World

System administrators often need to check and manage file system types on servers to ensure compatibility and performance.

💼 Career

Knowing how to script file system checks helps in automating server maintenance and troubleshooting tasks.

1

Create a list of mounted drives with file system types

Create a variable called mounted_drives that is a list of dictionaries. Each dictionary should have keys drive and fs_type. Use these exact entries: {'drive': '/dev/sda1', 'fs_type': 'ext4'}, {'drive': '/dev/sdb1', 'fs_type': 'xfs'}, {'drive': '/dev/sdc1', 'fs_type': 'ntfs'}, {'drive': '/dev/sdd1', 'fs_type': 'ext4'}.

Linux CLI

# Create the list mounted_drives with the exact entries
# Your code here

Hint

Use a list with dictionaries. Each dictionary has keys 'drive' and 'fs_type' with the exact values given.

2

Add a variable for file system types to filter

Create a variable called filter_fs_types that is a list containing the strings 'ext4' and 'xfs'.

Linux CLI

mounted_drives = [
    {'drive': '/dev/sda1', 'fs_type': 'ext4'},
    {'drive': '/dev/sdb1', 'fs_type': 'xfs'},
    {'drive': '/dev/sdc1', 'fs_type': 'ntfs'},
    {'drive': '/dev/sdd1', 'fs_type': 'ext4'}
]
# Create filter_fs_types list with 'ext4' and 'xfs'
# Your code here

Hint

Make a list with the two file system types as strings.

3

Filter drives by file system types

Create a variable called filtered_drives that uses a list comprehension to select only dictionaries from mounted_drives where the fs_type is in filter_fs_types.

Linux CLI

mounted_drives = [
    {'drive': '/dev/sda1', 'fs_type': 'ext4'},
    {'drive': '/dev/sdb1', 'fs_type': 'xfs'},
    {'drive': '/dev/sdc1', 'fs_type': 'ntfs'},
    {'drive': '/dev/sdd1', 'fs_type': 'ext4'}
]
filter_fs_types = ['ext4', 'xfs']
# Use list comprehension to create filtered_drives
# Your code here

Hint

Use a list comprehension with d for d in mounted_drives if d['fs_type'] in filter_fs_types.

4

Print the filtered drives

Use a for loop to print each drive and its file system type from filtered_drives in the format: Drive: [drive], File System: [fs_type].

Linux CLI

mounted_drives = [
    {'drive': '/dev/sda1', 'fs_type': 'ext4'},
    {'drive': '/dev/sdb1', 'fs_type': 'xfs'},
    {'drive': '/dev/sdc1', 'fs_type': 'ntfs'},
    {'drive': '/dev/sdd1', 'fs_type': 'ext4'}
]
filter_fs_types = ['ext4', 'xfs']
filtered_drives = [d for d in mounted_drives if d['fs_type'] in filter_fs_types]
# Print each drive and its file system type
# Your code here

Hint

Use a for loop and an f-string to print each drive and its file system type exactly as shown.

Practice

1. Which command is used to create an ext4 file system on a disk partition?

easy

A. format /dev/sdX1

B. mkfs.xfs /dev/sdX1

C. mkfs.ext4 /dev/sdX1

D. diskformat ext4 /dev/sdX1

Solution

1. Step 1: Understand the command for ext4 file system creation

   The command mkfs.ext4 is specifically designed to create ext4 file systems on a given partition.

2. Step 2: Identify the correct usage with device name

   Using mkfs.ext4 /dev/sdX1 formats the partition /dev/sdX1 as ext4.

3. Final Answer:

   mkfs.ext4 /dev/sdX1 -> Option C

4. Quick Check:

   ext4 creation command = mkfs.ext4 [OK]

Hint: ext4 uses mkfs.ext4 command to format partitions [OK]

Common Mistakes:

• Confusing mkfs.xfs with mkfs.ext4
• Using generic format commands not valid in Linux
• Trying to use unsupported commands like diskformat

2. Which of the following is the correct syntax to create an XFS file system on /dev/sdb1?

easy

A. mkfs.ext4 /dev/sdb1

B. mkfs.xfs /dev/sdb1

C. mkfs.xfs -t xfs /dev/sdb1

D. format xfs /dev/sdb1

Solution

1. Step 1: Identify the command for XFS file system creation

   The command mkfs.xfs is the standard way to create an XFS file system on a partition.

2. Step 2: Confirm the correct device usage

   Using mkfs.xfs /dev/sdb1 formats the partition /dev/sdb1 as XFS.

3. Final Answer:

   mkfs.xfs /dev/sdb1 -> Option B

4. Quick Check:

   XFS creation command = mkfs.xfs [OK]

Hint: Use mkfs.xfs for XFS file system creation [OK]

Common Mistakes:

• Using mkfs.ext4 instead of mkfs.xfs
• Trying mkfs.xfs -t xfs which is invalid syntax
• Using Windows-like format commands

3. What will be the output of the command file -s /dev/sdc1 after formatting /dev/sdc1 with ext4?

medium

A. /dev/sdc1: Linux rev 1.0 ext4 filesystem data

B. /dev/sdc1: XFS filesystem data

C. /dev/sdc1: data

D. /dev/sdc1: DOS/MBR boot sector

Solution

1. Step 1: Understand the file command with -s option

   The file -s command reads the device or file to identify its type.

2. Step 2: Recognize the output for ext4 formatted partition

   After formatting with ext4, the output shows Linux rev 1.0 ext4 filesystem data indicating ext4 file system.

3. Final Answer:

   /dev/sdc1: Linux rev 1.0 ext4 filesystem data -> Option A

4. Quick Check:

   file -s on ext4 = ext4 filesystem data [OK]

Hint: file -s shows filesystem type on device [OK]

Common Mistakes:

• Expecting XFS output after ext4 format
• Confusing raw data output with filesystem info
• Assuming DOS/MBR boot sector output on formatted partition

4. You ran mkfs.ext4 /dev/sdd1 but got an error: "device is mounted". What is the best fix?

medium

A. Unmount the device using umount /dev/sdd1 and retry

B. Use mkfs.xfs instead of ext4

C. Reboot the system and run the command again

D. Format a different device without unmounting

Solution

1. Step 1: Understand the error cause

   The error "device is mounted" means the partition is currently in use and cannot be formatted.

2. Step 2: Unmount the device before formatting

   Using umount /dev/sdd1 frees the device so mkfs.ext4 can run successfully.

3. Final Answer:

   Unmount the device using umount /dev/sdd1 and retry -> Option A

4. Quick Check:

   Unmount device before formatting = umount [OK]

Hint: Unmount device before formatting to avoid errors [OK]

Common Mistakes:

• Trying different filesystem without unmounting
• Rebooting unnecessarily instead of unmounting
• Ignoring the mounted status and forcing format

5. You need a file system for a large data server that requires fast write speed and supports files larger than 16TB. Which file system should you choose?

hard

A. ext4

B. NTFS

C. FAT32

D. XFS

Solution

1. Step 1: Analyze file system limits and performance

   ext4 supports large files but has a practical limit around 16TB; XFS supports very large files and is optimized for high-speed writes.

2. Step 2: Match requirements to file system features

   XFS is designed for large data servers with fast write speeds and supports files larger than 16TB, making it the best choice.

3. Final Answer:

   XFS -> Option D

4. Quick Check:

   Large fast files = XFS [OK]

Hint: Choose XFS for large files and fast writes on servers [OK]

Common Mistakes:

• Choosing ext4 without checking file size limits
• Selecting FAT32 which has small file size limits
• Confusing NTFS as a Linux-native file system