Arch Linux Btrfs Guide

Complete beginner-friendly guide to Btrfs on Arch Linux, including installation, subvolumes, snapshots, compression, and Btrfs management.

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Table of Contents

1. Understanding Btrfs
2. Creating Btrfs
3. Subvolumes
4. Snapshots
5. Compression
6. Troubleshooting

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Understanding Btrfs

What is Btrfs?

Btrfs is modern filesystem with advanced features.

Features:

• Snapshots
• Compression
• Copy-on-write
• Subvolumes
• RAID support

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Creating Btrfs

Format Btrfs

Create filesystem:

# Format as Btrfs
sudo mkfs.btrfs /dev/sda1

# With label
sudo mkfs.btrfs -L "MyData" /dev/sda1

Mount Btrfs

Mount:

# Mount
sudo mount /dev/sda1 /mnt/data

# With compression
sudo mount -o compress=zstd /dev/sda1 /mnt/data

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Subvolumes

Create Subvolume

Create subvolume:

# Create subvolume
sudo btrfs subvolume create /mnt/data/subvol1

# List subvolumes
sudo btrfs subvolume list /mnt/data

# Delete subvolume
sudo btrfs subvolume delete /mnt/data/subvol1

Mount Subvolume

Mount subvolume:

# Mount subvolume
sudo mount -o subvol=subvol1 /dev/sda1 /mnt/subvol1

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Snapshots

Create Snapshot

Create snapshot:

# Create snapshot
sudo btrfs subvolume snapshot /mnt/data /mnt/data/snapshot-$(date +%Y%m%d)

# List snapshots
sudo btrfs subvolume list /mnt/data

Restore Snapshot

Restore:

# Delete corrupted subvolume
sudo btrfs subvolume delete /mnt/data/corrupted

# Restore from snapshot
sudo btrfs subvolume snapshot /mnt/data/snapshot-20240115 /mnt/data/restored

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Compression

Enable Compression

Set compression:

# Mount with compression
sudo mount -o compress=zstd /dev/sda1 /mnt/data

# Or in fstab
UUID=xxxx-xxxx /mnt/data btrfs defaults,compress=zstd 0 2

Compression Levels

Compression options:

• zlib: Good compression
• lzo: Fast compression
• zstd: Balanced (recommended)

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Troubleshooting

Btrfs Errors

Check filesystem:

# Check Btrfs
sudo btrfs check /dev/sda1

# Scrub
sudo btrfs scrub start /mnt/data

Balance Filesystem

Balance:

# Balance filesystem
sudo btrfs balance start /mnt/data

# Check usage
sudo btrfs filesystem usage /mnt/data

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Summary

This guide covered Btrfs creation, subvolumes, snapshots, compression, and troubleshooting.

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Next Steps

• Arch Linux Filesystem Management - Filesystems
• Arch Linux Backup and Restore - Backups
• ArchWiki Btrfs: https://wiki.archlinux.org/title/Btrfs

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This guide is based on the ArchWiki. For the most up-to-date information, always refer to the official ArchWiki.