ext4 vs btrfs (October 2025)

on



If filesystems were cities, ext4 would be the tidy, reliable capital—broad avenues, predictable traffic lights, zero surprises. Btrfs would be the modern smart-city—sensors everywhere, self-healing roads, lanes that appear when you need them, and yes, the occasional construction sign. In 2025, both remain first-class citizens of Linux. Which one should you install, trust, and tune? Let’s dive in—hard numbers where they matter, street-savvy advice everywhere else.

Quick verdict

  • Choose ext4 if you prize absolute stability, minimal surprises, and consistent performance on everything from Raspberry Pi SD cards to enterprise NVMe arrays. It’s the “just works” default in many distros and servers.

  • Choose Btrfs if you want transparent compression, checksummed data+metadata, snapshots, send/receive, and integrated volume management—with a desktop-friendly UX in Fedora and a polished snapshot workflow in openSUSE. Avoid Btrfs RAID5/6. Prefer mirrors (RAID1/1c3/1c4) or single-disk with backups.

What’s new(ish) by late 2025

  • Desktop defaults: Fedora’s Workstation images continue to ship Btrfs as the default for the root filesystem, leaning on compression and subvolumes for space efficiency and easier reinstalls. openSUSE defaults to Btrfs on root with Snapper snapshots and one-click rollbacks from GRUB. Ubuntu LTS still installs ext4 by default unless you opt in to something else.

  • Performance landscape: On bleeding-edge NVMe, recent public test sets show Btrfs trending competitive under heavier write concurrency (especially with compression) while the usual speed kings shuffle by workload (F2FS/XFS can win specific write-heavy tasks). ext4 remains a steady all-rounder. Translation: you won’t bottleneck a typical desktop with either, but Btrfs’s compression can make small/medium IO feel snappier.

  • RAID reality check: In 2025, Btrfs RAID5/6 is still not recommended. Use mirrors (RAID1, 1c3, 1c4) or single-device plus backups.

The big picture: how they think

ext4: journaled classic with modern touches

  • Extent-based allocation, mature journaling, online resize, 64-bit scalability, casefold for case-insensitive dirs (handy for cross-platform dev), fs-verity support for authenticity verification. A conservative design with decades of burn-in.

Btrfs: copy-on-write Swiss Army knife

  • Checksums on data and metadata, snapshots (instant, space-efficient), subvolumes, transparent compression (zstd), send/receive, self-healing on mirrored profiles, and pooled storage across devices. It’s a filesystem and a lightweight volume manager.

Real-world scenarios (pick your lane)

1) Laptops & developer workstations

  • ext4: Fewer moving parts. Predictable on any kernel, any distro. Great for dual-boot simplicity.

  • Btrfs: Turn on zstd compression and enjoy smaller disk footprints, faster reads on many mixed workloads, roll back a bad update in seconds, snapshot before risky package upgrades. Fedora/openSUSE make this almost push-button.

Rule of thumb: If your distro integrates Btrfs tools well (Snapper, snapper-plugins, default subvolumes), Btrfs shines on daily drivers. Otherwise, ext4 is the boring hero you’ll never have to think about.

2) Content creators (photo/video/audio)

  • High throughput loves simple pipelines. ext4 remains a safe default for scratch disks where raw sequential performance and predictability matter.

  • Btrfs with noatime and compression=zstd:3..6 can reduce disk usage substantially for footage libraries and project trees, and snapshots are fantastic before major edits—just avoid RAID5/6.

3) Servers & homelabs

  • For VMs/containers, Btrfs snapshots and send/receive enable quick rollbacks and efficient replication. Mirrored profiles (RAID1/1c3/1c4) plus scrubs give silent-corruption detection and self-healing.

  • If you want set-and-forget plus battle-tested consistency on mixed workloads, ext4 remains compelling—especially when higher-level RAID/LVM/ZFS handles redundancy above it.

4) Distro culture and tooling

  • Fedora Workstation: Btrfs first; subvolumes for root/home, compression, friendly docs.

  • openSUSE: Btrfs root + Snapper with GRUB rollback flow—clean and confidence-boosting.

  • Ubuntu LTS: ext4 default install path; Btrfs is available if you choose it manually.

Performance notes you can actually use

  • Compression = free speed (often): Btrfs with zstd can make many desktop tasks faster by reading less from disk. On cutting-edge NVMe with lots of cores, Btrfs scales better than you might expect as concurrency rises. Don’t expect miracles on already-compressed media (H.264/265, JPEG).

  • Small writes and metadata churn: ext4’s simpler design often looks steadier here. Btrfs’s COW can amplify write-amplification in specific patterns; balance and defrag tools exist—but they’re knobs you’ll actually need to know.

  • Database-y loads: If you’re serious about DB performance, test your workload. ext4 is a safe baseline; XFS/F2FS can win certain write-heavy patterns; Btrfs is no slouch with modern kernels and compression—but benchmarking your exact mix pays off.

Reliability & recovery

  • ext4: Decades of production use, mature fsck, conservative feature set. If your mental model is “I don’t want features, I want certainty,” ext4 is comfort food.

  • Btrfs: Checksums catch silent corruption; scrubs verify data; mirrored profiles can self-heal. Snapshots + bootloader integration (openSUSE) let you roll back system breakage cleanly—even from GRUB. Just mind the RAID5/6 caveat.

Tuning cheat-sheet

  • ext4

    • Mount: noatime,commit=120 for fewer journal commits on laptops, lazytime for metadata write-back.

    • Features: enable casefold selectively for cross-platform dev trees that expect case-insensitive paths (e.g., web projects targeting macOS/Windows).

  • Btrfs

    • Mount: compress=zstd:3 (or :6 if CPU is ample), ssd, noatime, consider autodefrag for many small random writes.

    • Ops: schedule scrub monthly; balance lightly to avoid fragment storms; snapshot before upgrades; avoid RAID5/6; prefer RAID1/1c3/1c4 for bit-rot resilience with multiple devices.

The SEO-friendly bottom line

  • ext4 is the rock—simple, stable, universal. If you never want to think about your filesystem again, pick ext4 and get on with your life.

  • Btrfs is the feature powerhouse—compression, snapshots, checksums, send/receive, subvolumes. In distros that truly integrate it (Fedora, openSUSE), it’s a productivity multiplier for devs and desktop power users—with the explicit exception of RAID5/6.

Recommendation:

  • Desktops/laptops (Fedora/openSUSE) → Btrfs.

  • Servers/minimal images/portable disks → ext4 (or Btrfs only if you need its features and are willing to learn its knobs).

  • RAID at home → Btrfs mirrors or use mdraid/ZFS above ext4; skip Btrfs RAID5/6 in 2025.

FAQ (because you’ll ask anyway)

Is Btrfs finally “ready”?
For single-disk and mirrored setups on mainstream distros: yes. For RAID5/6: no.

Will Btrfs speed up my old laptop?
Often yes, because of compression reducing IO. But if your CPU is very weak, test with zstd:1..3 first.

Why do some distros still default to ext4?
Conservatism and broad hardware coverage. Ubuntu’s LTS path values the extremely low-surprise profile of ext4 by default—Btrfs remains available for those who want it.

Can I roll back a bad update?
On openSUSE, yes—from GRUB—thanks to Btrfs snapshots + Snapper integration. On other distros, it depends on how they wire snapshots into the boot process.

TL;DR



  • ext4: Zero drama, universal, fast enough everywhere.

  • Btrfs: Modern tricks, real safety nets, and a smoother daily ride—when paired with the right distro and sane profiles. Fedora and openSUSE show how it’s done.

Pick your city. Pave your roads. And for heaven’s sake—keep backups.

Comments

Post a Comment