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Traditional Rsync backups work well, but they don't capture point-in-time snapshots, making restoration difficult in case of accidental deletions or corruption.

ZFS and Btrfs are modern file systems that support snapshots, which provide fast, space-efficient backups with Rsync for remote replication.

📌 In this guide, you will learn:
✅ How to create and manage snapshots with ZFS and Btrfs
✅ How to integrate Rsync for remote snapshot backups
✅ How to restore files from snapshots efficiently
✅ How to automate snapshot-based backups

🛑 1. Why Use Snapshots with Rsync?

🔹 Instant Backups – Snapshots take seconds, unlike full Rsync syncs.
🔹 Low Storage Overhead – Only changes are stored (copy-on-write).
🔹 Fast Recovery – Restore individual files or entire datasets.
🔹 Protect Against Rsync Errors – If an Rsync backup goes wrong, snapshots provide a fallback.

✅ Solution: Use ZFS or Btrfs snapshots with Rsync for reliable, space-efficient backups.

⚡ 2. Using Rsync with ZFS Snapshots

🔹 2.1 Setting Up ZFS (If Not Installed)

✅ Install ZFS on Ubuntu/Debian:

sudo apt install zfsutils-linux -y

✅ Install ZFS on CentOS/RHEL:

sudo yum install zfs -y

✅ Verify Installation:

zfs version

🔹 2.2 Creating a ZFS Storage Pool

✅ Create a ZFS pool named backup-pool (Replace sdX with your actual disk):

sudo zpool create backup-pool /dev/sdX

✅ Create a ZFS dataset (sub-volume) for backups:

sudo zfs create backup-pool/data

📌 Now, all backups will be stored under /backup-pool/data.

✅ Set a compression level to save space:

sudo zfs set compression=lz4 backup-pool/data

📌 lz4 compression speeds up backups without CPU overhead.

🔹 2.3 Taking ZFS Snapshots Before Rsync

✅ Create a snapshot before running Rsync:

sudo zfs snapshot backup-pool/data@before-backup

📌 This ensures that Rsync operates on a stable, unchanging dataset.

✅ Verify the snapshot:

zfs list -t snapshot

📌 You should see backup-pool/data@before-backup.

✅ Send the snapshot to a remote backup server using Rsync:

rsync -avz /backup-pool/data/ user@remote:/backup/

📌 Now, your data is safely backed up.

🔹 2.4 Restoring from a ZFS Snapshot

✅ If Rsync corrupted files, restore the snapshot:

sudo zfs rollback backup-pool/data@before-backup

📌 Instantly restores the dataset to its previous state.

✅ If only a specific file needs restoring:

cp /backup-pool/data/.zfs/snapshot/before-backup/important-file /backup-pool/data/

📌 Restores a single file without affecting other data.

📀 3. Using Rsync with Btrfs Snapshots

🔹 3.1 Setting Up Btrfs (If Not Installed)

✅ Install Btrfs on Ubuntu/Debian:

sudo apt install btrfs-progs -y

✅ Install Btrfs on CentOS/RHEL:

sudo yum install btrfs-progs -y

✅ Verify Installation:

btrfs --version

🔹 3.2 Creating a Btrfs Storage Volume

✅ Create a Btrfs filesystem on /dev/sdX:

sudo mkfs.btrfs /dev/sdX

✅ Mount the Btrfs volume:

sudo mkdir /mnt/backup-btrfs
sudo mount /dev/sdX /mnt/backup-btrfs

📌 Now, backups will be stored under /mnt/backup-btrfs/.

✅ Enable compression for storage savings:

sudo btrfs property set /mnt/backup-btrfs compression lzo

📌 lzo compression improves speed and efficiency.

🔹 3.3 Taking Btrfs Snapshots Before Rsync

✅ Create a snapshot before running Rsync:

sudo btrfs subvolume snapshot /mnt/backup-btrfs /mnt/backup-btrfs/snap_before_backup

📌 This creates /mnt/backup-btrfs/snap_before_backup, a read-only snapshot.

✅ Verify the snapshot:

sudo btrfs subvolume list /mnt/backup-btrfs

📌 Shows all available snapshots.

✅ Send the snapshot to a remote server using Rsync:

rsync -avz /mnt/backup-btrfs/snap_before_backup/ user@remote:/backup/

📌 This ensures a clean, consistent backup.

🔹 3.4 Restoring from a Btrfs Snapshot

✅ Rollback the entire backup if Rsync fails:

sudo btrfs subvolume delete /mnt/backup-btrfs
sudo btrfs subvolume snapshot /mnt/backup-btrfs/snap_before_backup /mnt/backup-btrfs

📌 Reverts the dataset to the pre-backup state.

✅ Restore a single file from a snapshot:

cp /mnt/backup-btrfs/snap_before_backup/important-file /mnt/backup-btrfs/

📌 Recovers a single file without affecting the entire backup.

🔄 4. Automating Snapshot-Based Rsync Backups

🔹 4.1 Create a Snapshot & Rsync Backup Script

✅ Save the following script as /usr/local/bin/snapshot-backup.sh:

#!/bin/bash

# Directories
BACKUP_DIR="/mnt/backup-btrfs"
SNAPSHOT_NAME="snap_$(date +%Y%m%d%H%M)"
REMOTE_SERVER="user@remote:/backup/"

# Create a new snapshot
sudo btrfs subvolume snapshot "$BACKUP_DIR" "$BACKUP_DIR/$SNAPSHOT_NAME"

# Rsync the snapshot to a remote server
rsync -avz "$BACKUP_DIR/$SNAPSHOT_NAME/" "$REMOTE_SERVER"

echo "Backup completed successfully!"

✅ Make the script executable:

chmod +x /usr/local/bin/snapshot-backup.sh

✅ Schedule it to run daily:

crontab -e

✅ Add the following line:

0 2 * * * /usr/local/bin/snapshot-backup.sh

📌 Runs the backup every night at 2 AM.

⚠️ 5. Troubleshooting Rsync with Snapshots

✅ Debug snapshot issues:

zfs list -t snapshot
btrfs subvolume list /mnt/backup-btrfs

📌 Shows available snapshots for rollback.

📊 6. Summary

✅ Using Rsync with ZFS or Btrfs snapshots ensures fast, reliable, and space-efficient backups.

💬 Join the Discussion!

Do you prefer ZFS or Btrfs for snapshots?
How do you use Rsync with snapshot-based backups?

💬 Share your experience in the comments below! 🚀

👉 Next Up: Combining Rsync with Rsnapshot for Incremental Backups