Skip to content

Btrfs vs. EXT4: An In-Depth Guide to Choosing the Right Filesystem for Your Linux Installation

Hey friend! So you‘re looking to set up a new Linux system and wondering about the age-old question – should you use Btrfs or EXT4 as the filesystem? If so, you‘ve come to the right place. In this comprehensive guide, we‘ll dive deep into the differences between these two popular options to help you pick the best one for your needs.

An Overview of The Main Contenders

When setting up a Linux installation, one of the first key decisions is which filesystem to use. The filesystem manages how data is stored, accessed and manipulated in your operating system. There are several to choose from, but two heavyweights have emerged over time – Btrfs and EXT4.

Btrfs (B-tree filesystem) is the newcomer, introduced in 2007 by Oracle as a next-generation filesystem boasting advanced features like snapshots, compression, and built-in RAID support. However, it is still considered experimental.

EXT4 has decades of history dating back to 1993. As the successor to the EXT filesystem family, it improves performance and storage limits while providing a stable and reliable option for Linux distributions.

So which one is right for you? In this guide, we‘ll compare the key differences between Btrfs and EXT4 to help you make an informed decision based on your needs. Ready? Let‘s do this!

Understanding The Core Differences

Btrfs and EXT4 differ significantly in how they structure and write filesystem data to storage.

Btrfs uses copy-on-write, meaning that whenever data is modified, it first makes a copy of the existing data before applying the changes. This preserves data integrity, acting like having incremental backups of the filesystem state.

EXT4 uses journaling, writing metadata to a journal or log before the main filesystem. This tracks changes so the filesystem can recover more easily in case of crashes or power loss.

These fundamental approaches impact other behaviors:

  • Performance: EXT4 generally has faster read/write speeds. Btrfs can run faster in some workloads with proper configuration.
  • Fragmentation: Btrfs is more prone to fragmentation over long-term usage while EXT4 defragments better.
  • Integrity: For transaction-heavy uses like databases, EXT4‘s journaling excels. For frequently changing files, Btrfs‘ copy-on-write approach protects better.

Now let‘s look at some of the key features supported by each.

Feature Comparison

Feature Btrfs EXT4
Snapshots Yes No
Compression Yes No
Deduplication Yes No
RAID Support Yes No
Checksumming Yes No
Max Partition Size 16 exbibytes 16 tebibytes
Max Files 18 quintillion 4 billion
Max File Size 16 exbibytes 1 exbibyte

Btrfs provides many advanced features that EXT4 lacks like compression, deduplication, integrated RAID and checksums to detect data corruption. Its copy-on-write nature also enables full filesystem snapshots and easy restores.

However, EXT4 has some limits like maximum partition sizes and number of files that are an order of magnitude higher than most real-world use cases. The simplicity of EXT4 also makes it less prone to errors.

So why doesn‘t everyone just use Btrfs then? The answer is stability and maturity, which we‘ll explore next.

Reliability and Maturity

EXT4 has over 25 years of real-world deployment across countless Linux installations. It‘s tried, tested and proven to be stable and reliable. The likelihood of losing data or suffering filesystem corruption issues is extremely low.

Btrfs, while showing promise, still suffers growing pains in stability and fragmentation after prolonged use. Small errors can quickly snowball into bigger problems if you‘re not careful. It‘s generally not recommended for mission-critical systems that need to be online 24/7 just yet.

For this reason, the majority of Linux server distributions like RHEL, CentOS, Ubuntu and SUSE still default to EXT4 – it‘s the safe choice enterprises depend on.

Home users and non-critical systems may want to experiment with Btrfs to take advantage of its features, but do so knowing that you‘re more likely to encounter issues compared to the rock-solid stability of EXT4.

Performance and Scaling Comparison

To get a better sense of how Btrfs and EXT4 differ in real-world performance and scaling, let‘s look at some benchmarks.

First, a simple read/write workload comparing basic I/O operations per second on an SSD drive:

Btrfs EXT4
Sequential Read 550 MB/s 558 MB/s
Sequential Write 515 MB/s 526 MB/s
Random Read 45k IOPS 53k IOPS
Random Write 107k IOPS 114k IOPS

Source

As you can see, EXT4 generally outperforms Btrfs in basic I/O workloads, although not by much on SSD storage. The performance gap is larger on rotational media like HDDs.

For heavy database workloads at scale, EXT4 also maintains a significant advantage in transactions per minute:

Btrfs EXT4
Database TpmC 6,768 7,604

Source

This demonstrates the maturity of EXT4‘s journaling and keen OS integration that gives it better performance for write-intensive applications.

However, Btrfs can be faster for workloads involving lots of file creations and deletions:

Btrfs EXT4
Kernel Compiles 37 sec 46 sec
File creations 161 sec 192 sec

Source

Thanks to copy-on-write, Btrfs handles rapid changes better than the journaling of EXT4. For databases though, EXT4 remains king.

Ideal Use Cases Compared

Now that we‘ve seen the key differences in reliability, performance and features, which use cases are each filesystem best suited for?

EXT4 is the safe choice and works great across the board, which is why it remains the default for most Linux installations. Specific applications where EXT4 excels include:

  • File and application servers
  • Database servers
  • Enterprise production systems
  • Desktop and laptop OS installations
  • Critical data you cannot afford to lose

Btrfs is best for scenarios where advanced features are beneficial or you‘re willing to sacrifice a bit of stability for greater flexibility:

  • Personal and home media servers
  • Network-attached storage (NAS)
  • Virtual machine drives
  • Non-critical data you have backups of
  • Laptops and devices needing snapshots
  • prioritizing compression or deduplication

The risks of using Btrfs are lower for home systems and secondary storage where regular backups are done. Avoid it for mission-critical primary storage still.

What About Other Filesystems?

If your use case falls outside the strengths of Btrfs and EXT4, there are alternatives to consider like XFS, ZFS and ReiserFS:

XFS is optimized for high throughput and large filesystems, making it great for large storage and media servers. It efficiently scales to petabytes without much performance loss. Reliability with crash recovery is also excellent.

ZFS simplifies managing large storage with pooled disks and native software RAID. Its redundancy features make it ideal for mass storage and backups. However, it requires significant RAM.

ReiserFS is more complex but highly customizable using extensions and plugins. It can also be deployed across operating systems, although stability and support lags behind Linux-native options.

Each filesystem has its niche. For most general server and desktop use cases, EXT4 remains the favorite. For exotic needs around big data and scale-out storage, the alternatives are worth investigating.

The Verdict: Should You Use Btrfs or EXT4?

So what‘s the final verdict if you‘re facing the choice between Btrfs and EXT4 today?

For servers and business-critical data, stick with EXT4 as the reliable, stable default. Its decades of proven performance across the Linux ecosystem make it the trusted choice for minimizng disruptions.

For desktops and home use, Btrfs is worth considering if you want better snapshots and ability to recover from accidental deletions or filesystem corruption. Just be diligent with backups!

Over time, Btrfs may mature further to become a more viable EXT4 successor across the board. But for now, understand the tradeoffs in stability vs features and pick the right filesystem for your needs.

I hope this guide has given you a comprehensive overview of the Btrfs vs EXT4 decision now and for years to come! Let me know if you have any other questions.