Linux - File System Types in Linux (ext4, XFS, Btrfs)

A file system controls how data is stored, organized, and retrieved on a disk.
Different file systems offer different features like performance, reliability, snapshots, and scalability.

Linux supports many file systems, but ext4, XFS, and Btrfs are the most commonly used.

1. ext4 (Fourth Extended Filesystem)

Most stable and widely used filesystem in Linux

ext4 is the default filesystem in many Linux distributions (Ubuntu, Debian, etc.).

Key Features

  • Very stable and mature

  • Efficient performance for general workloads

  • Handles large files and directories

  • Journaling for data safety

  • Low chance of corruption

  • Excellent compatibility across Linux systems

Supports

  • Max file size: 16 TB

  • Max filesystem size: 1 EB (exabyte)

Best For

  • Servers

  • Desktops

  • Laptops

  • Production systems where stability matters most

Limitations

  • No built-in snapshot support

  • No built-in compression or deduplication

  • Hard to fix after major corruption compared to Btrfs

2. XFS (High-Performance File System)

Optimized for scalability and high-speed I/O

XFS is known for its excellent performance, especially with large files and multi-threaded workloads.
Default filesystem in RHEL/CentOS.

Key Features

  • High performance for large files

  • Extremely good at parallel read/write operations

  • Journaling (fast crash recovery)

  • Online resizing (grow easily)

  • Very scalable for enterprise workloads

Supports

  • Max file size: 8 exabytes

  • Max filesystem size: 8 exabytes

Best For

  • Databases (MySQL, Postgres)

  • Large media storage

  • High-performance servers

  • Enterprise applications

Limitations

  • Cannot shrink partitions

  • No built-in snapshot/compression features

  • Recovery tools are limited compared to ext4

3. Btrfs (B-Tree File System)

A modern, advanced filesystem with powerful features

Btrfs is designed to be the "next-generation" filesystem with advanced capabilities.

Key Features

  • Snapshots (fast, instant)

  • Subvolumes

  • Native compression (zstd, lzo)

  • RAID (0/1/5/6/10) built-in

  • Self-healing with checksums

  • Copy-on-Write (CoW)

  • Ability to shrink/grow

Supports

  • Max file size: 16 exabytes

  • Max filesystem size: 16 exabytes

Best For

  • Systems needing snapshots (development servers)

  • Containers (Docker, LXC)

  • Workloads benefiting from compression

  • Rolling-release distros (openSUSE, Fedora)

Limitations

  • RAID 5/6 still considered unstable

  • Slightly slower performance for databases

  • Not as battle-tested as ext4 for critical production

Comparison Table

Feature ext4 XFS Btrfs
Stability ⭐⭐⭐⭐⭐ ⭐⭐⭐⭐ ⭐⭐⭐⭐
Performance ⭐⭐⭐⭐ ⭐⭐⭐⭐⭐ ⭐⭐⭐
Snapshots ❌ ❌ ✅
Compression ❌ ❌ ✅
RAID support ❌ ❌ ✅ (built-in)
Good for large files ⭐⭐⭐ ⭐⭐⭐⭐⭐ ⭐⭐⭐⭐
Shrinking FS ❌ ❌ ✅
Default in Ubuntu, Debian RHEL/CentOS openSUSE, Fedora (optional)

Which File System Should You Use?

✔ Choose ext4 if you want stability and reliability

Ideal for: normal servers, desktops, production systems.

✔ Choose XFS for performance with large files or enterprise workloads

Ideal for: databases, high-end servers, virtual machines.

✔ Choose Btrfs if you want advanced features

Ideal for: snapshot-based backups, versioning, containers, home systems.