Linux Partition Concept and Disk Management Explained

Introduction

When you install Linux, one of the most important steps is creating partitions.
A partition is simply a way to divide your hard disk into separate sections.
Think of it as dividing a house into different rooms – each room has a purpose.

What is a Partition?

A partition is a logical section of your disk.
Linux needs partitions to store the operating system, user data, and swap memory.

Common Linux Partitions

• / (Root Partition): This is the main partition. It contains system files, programs, and configurations.
• /home: Stores user data like documents, downloads, and settings.
• /boot: Contains boot loader files (needed to start Linux).
• Swap: Works as virtual memory when RAM is full.
• /var: Stores variable files like logs and temporary data.
• /tmp: Temporary files for applications.

What is a File System?

A file system decides how files are stored and organized on a partition.
Without a file system, Linux cannot read or write data.

Common Linux File Systems

• ext4: Most widely used, reliable, and stable.
• xfs: Good for large files, used in servers.
• btrfs: Advanced features like snapshots and self-healing.
• vfat/exFAT: Compatible with Windows systems (used in USB drives).

Disk Partitioning Types

• MBR (Master Boot Record): Old method, supports up to 2TB disks and 4 primary partitions.
• GPT (GUID Partition Table): Modern method, supports large disks and unlimited partitions.

Disk Management in Linux

You can manage partitions and disks using various commands:

Useful Commands

• lsblk – Show all block devices (disks and partitions).
• fdisk -l – Display partition table (MBR disks).
• gdisk -l – Display partition table (GPT disks).
• df -h – Show disk usage of mounted partitions.
• mount – Mount a partition to a directory.
• umount – Unmount a partition.
• mkfs.ext4 /dev/sdb1 – Format a partition with ext4 file system.

Best Practices for Linux Partitions

• Always separate /home from / so user data is safe during OS reinstallation.
• Use /var separately on servers to prevent logs from filling the root partition.
• Allocate enough swap (usually equal to RAM, but max 4GB for desktops, higher for servers).
• Use ext4 for general systems, xfs for large data servers, and btrfs if you need snapshots.
• Regularly monitor disk space with df -h and du -sh.

Interview Tips

If you are preparing for a Linux Administrator interview, remember:

• Be ready to explain the difference between MBR and GPT.
• Know the purpose of /boot, /home, /var, and swap.
• Understand how to check disk usage and extend partitions.
• Be aware of common file systems and where they are used.

Conclusion

Disk partitioning is the foundation of Linux system administration.
By understanding partitions, file systems, and disk management,
you can ensure better performance, stability, and security of your Linux servers.