Part of CachyOS Wiki Notes. From the official CachyOS wiki (last updated 2026-06-12).

CachyOS Filesystems

The installer offers five: XFS, BTRFS, EXT4, ZFS, F2FS — each with its utilities preinstalled.

BTRFS is the default and recommended. “Choose it if unsure.”

XFS

Journaling filesystem by SGI (1993; ported to Linux 2001).
Pro: built for speed and extreme scalability; multiple anti-corruption technologies; resistant to fragmentation (extent-based + delayed allocation).
Con: cannot be shrunk.
Package: xfsprogs.
For: simple, fast, reliable, no advanced features.

Copy-on-write filesystem (created 2007, declared stable in the kernel 2013).
Pro: transparent compression — CachyOS ships ZSTD level 3 by default; snapshots (COW, so they take very little space); subvolumes; can grow or shrink; fast development.
Con: sometimes needs defrag/balance; worse on rotational drives due to fragmentation.
Package: btrfs-progs.
Default subvolume layout: @ = /, @home = /home, @root = /root, @srv = /srv, @cache = /var/cache, @tmp = /var/tmp, @log = /var/log.
For: snapshot/backup functionality plus transparent compression.

Most commonly used Linux filesystem (stable in kernel 2008).
Pro: can be as fast or faster than XFS in some cases; huge amount of documentation; proven; can grow or shrink (shrinking is offline only and requires the FS to be unmounted).
Con: lacks many advanced features.
Package: e2fsprogs.
For: the simplest, most common choice.

Advanced FS by Sun (2005). CDDL-licensed, so it cannot live in the Linux kernel and needs a separate module. Do not use a real-time kernel with ZFS (licensing incompatibility).
Pro: pooled storage (zpool), COW snapshots, compression, Raid-Z, ARC cache (very fast reads of frequently accessed files).
Con: complicated; ARC needs a lot of RAM to be effective; out-of-tree OpenZFS module; incompatible with real-time preemption.
Tools: the ZFS-Module (CachyOS precompiles a zfs module per kernel version) and zfs-utils.
For: advanced users who want pooled storage or ARC.

Samsung’s Flash-Friendly File System, built for NAND flash.
Pro: flash-friendly design; transparent compression reduces writes (the space savings are not currently usable by the user); better wear leveling, longer NAND life.
Con: cannot shrink; compression savings unusable; weak fsck; downgrading to a kernel older than the one that created the FS may break things; needs a workaround with GRUB on MBR/BIOS.
Package: f2fs-tools.
For: maximizing NAND lifespan. Limine is the recommended bootloader for F2FS on MBR/BIOS (no workaround needed, unlike GRUB).