Choosing the Right Backup Solution: dd, rsync, borg, and fsarchiver

2025-03-29

Backing up data is essential for system reliability, disaster recovery, and peace of mind. There are various tools available, each suited for different use cases. This post compares four popular backup solutions: dd, rsync, borg, and fsarchiver, highlighting their strengths, weaknesses, and best use cases.

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1. dd: The Raw Disk Cloner

Overview

dd is a low-level tool that copies raw data from one location to another, making it ideal for disk imaging and cloning.

Pros

• Works at the block level, making exact copies of disks or partitions.
• Can be used for full system backups, including boot sectors and partition tables.
• Works with any filesystem or even raw devices.

Cons

• Inefficient for incremental backups (copies everything, even unchanged data).
• Can result in large backup sizes.
• A single corrupted block can affect the entire image.

Best Use Cases

• Creating full disk images for migration or recovery.
• Backing up bootable USBs or system partitions.
• Recovering data from failing drives using ddrescue (a specialized version of dd).

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2. rsync: The File Synchronizer

Overview

rsync efficiently copies and synchronizes files between directories, drives, or remote systems, supporting incremental backups.

Pros

• Efficient: Only transfers modified or new files, reducing backup time and storage use.
• Supports remote backups over SSH.
• Can exclude specific files or directories.
• Preserves file permissions, timestamps, and symbolic links.

Cons

• Does not handle deduplication or compression natively.
• Not ideal for full system backups (misses special system files, boot sectors, etc.).

Best Use Cases

• Syncing home directories or project files to a backup drive or server.
• Automating incremental daily backups.
• Keeping an offsite backup using a remote server.

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3. Borg: The Deduplicating Backup System

Overview

borg is a modern backup tool designed for deduplication, compression, and encryption, making it space-efficient and secure.

Pros

• Deduplication reduces storage by avoiding duplicate data.
• Built-in compression and encryption.
• Supports incremental backups.
• Fast restores due to its repository-based structure.

Cons

• Requires more setup compared to rsync.
• The backup repository format is proprietary to borg (requires borg to restore).

Best Use Cases

• Long-term incremental backups with minimal storage overhead.
• Encrypted backups for sensitive data.
• Ideal for laptops or servers where storage space is a concern.

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4. fsarchiver: The Flexible Filesystem Backup Tool

Overview

fsarchiver saves and restores filesystems efficiently while preserving attributes and supporting compression.

Pros

• Supports multiple filesystems, including ext4, NTFS, XFS, Btrfs, and more.
• Can restore a backup to a smaller partition, unlike dd.
• Handles compression natively.
• Can extract individual files from a backup.

Cons

• Not as widely used as other solutions.
• Does not support deduplication like borg.

Best Use Cases

• Backing up entire filesystems efficiently.
• Migrating data between partitions with different sizes.
• Creating compressed system backups.

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Comparison Table

Feature	dd	rsync	borg	fsarchiver
Incremental Backup	❌	✅	✅	❌
Compression	❌	❌	✅	✅
Deduplication	❌	❌	✅	❌
Filesystem Agnostic	✅	✅	✅	✅
Restores Individual Files	❌	✅	✅	✅
Remote Backup Support	❌	✅	✅	❌

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Which Backup Tool Should You Use?

• Use dd if you need a raw disk image for migration, cloning, or full system recovery.
• Use rsync if you need fast, incremental file backups with remote storage support.
• Use borg if you need efficient, encrypted, and deduplicated backups.
• Use fsarchiver if you want compressed filesystem backups with the flexibility to restore to different partition sizes.

Each tool has its strengths, and the best choice depends on your specific backup needs. A combination of tools may be ideal for comprehensive data protection.

What’s your preferred backup strategy? Let us know in the comments!