When it comes to data protection, choosing the right backup strategy can mean the difference between a smooth recovery and a catastrophic data loss. The two most common approaches—full backups and incremental backups—each offer advantages, but they also come with risks that organizations must consider.
If you have the storage space, should you rely on full backups for simplicity or use incremental backups to save time and resources? More importantly, what are the hidden dangers of incremental backups? Let's explore the pros, cons, and best practices for balancing efficiency and reliability.
What Are Full and Incremental Backups?
Full Backups: The Gold Standard of Data Protection
A full backup captures all data at a specific point in time, creating a complete copy that can be restored independently.
✅ Pros of Full Backups:
- Quick and efficient recovery process – Fast and straightforward recovery
- No reliance on prior backups – minimizing risks of data corruption
- Ideal for compliance – Ideal for compliance, long-term storage, and security
❌ Cons of Full Backups:
- Requires more storage – If you have the space, it's a good opportunity to keep comprehensive backups
- Takes longer to complete a backup – While it's more time-consuming, the process ensures all data is included at once.
- Puts a higher load on systems during backup – This may impact performance temporarily, but it guarantees you have a complete, up-to-date snapshot
An incremental backup only stores changes made since the last backup, whether full or incremental. This minimizes backup time and storage usage but complicates the recovery process.
✅ Pros of Incremental Backups:
- Reduces storage needs and backup time
- Minimizes system impact during backup operations
- Ideal for frequent backups (e.g., hourly or daily snapshots)
❌ Cons of Incremental Backups:
- Slower recovery time – The last full backup plus all incrementals must be restored in sequence.
- Higher risk of data loss – If one incremental backup is lost or corrupted, all backups afterward could be useless.
- Complex management – Long incremental chains require careful monitoring to prevent failures and increases the likelihood of mistakes during the recovery process.
- Harder to meet your RTO requirements – The longer the incremental chain, the more difficult it becomes to restore data quickly and meet recovery time objectives (RTO).
The Risks of Relying on Incremental Backups
While incremental backups offer efficiency, they introduce serious risks that can impact data reliability.
Single Point of Failure in the Backup Chain
Incremental backups depend on a sequence of previous backups. If any backup in the chain is lost or corrupted, it can render the entire dataset unrecoverable. This risk increases as the chain grows longer.
Slow and Complex Recovery
Unlike full backups, which restore in one step, recovering from incremental backups requires restoring the last full backup and every incremental backup taken since. This can take hours—or even days—depending on the number of incrementals.
Higher Risk of Corruption Over Time
Incremental backups accumulate over time, meaning even a minor corruption in one incremental file can affect all subsequent backups. Hardware failures, ransomware, or accidental deletions can make an entire backup chain unusable.
Data Fragmentation and Versioning Issues
Since each incremental backup contains only the changed data, files can become scattered across multiple backup files, leading to inconsistent recovery points and version confusion.
Increased Management Overhead
IT teams must carefully monitor backup chains, conduct integrity checks, and periodically refresh full backups to avoid excessive dependency on old incrementals.
What the Research Says
A recent study published in the Software Quality Journal titled "Periodic and Random Incremental Backup Policies in Reliability Theory" by Xufeng Zhao et al. analyzed the reliability of incremental backup strategies in 24/7 database environments.
- The study found that long incremental backup chains increase failure risks, especially when backup intervals are poorly managed.
- It emphasized the need for regular full backups to break incremental chains and improve reliability.
- It also highlighted the importance of integrity checks to detect corruption before recovery is needed.
For organizations relying heavily on incremental backups, this study reinforces the importance of a structured backup schedule and proactive monitoring.
The Best Approach: Hybrid Backup Strategy
To maximize both efficiency and reliability, a hybrid backup approach is ideal:
✅ Perform full backups weekly and monthly to ensure a clean and independent recovery point.
✅ Use incremental backups daily or hourly to capture frequent changes.
✅ Keep incremental chains short (e.g., limit to a week before another full backup).
✅ Run regular integrity checks to detect corruption early.
✅ Use object storage with deduplication (e.g., Myota) to reduce storage overhead while maintaining frequent full backups.
Backup Schedule – Here's a simple schedule for your backup strategy:
- Day 1 (Sunday): Full Backup
- Day 2–6 (Monday–Friday): Incremental Backups
- Day 7 (Saturday): Incremental Backup – Monthly Full Backup & Archival
Monthly Process
- The first full backup of the month is archived for long-term storage.
- All incremental backups reset after the monthly archival, and the cycle repeats.
Final Verdict: Full or Incremental?
- If fast recovery and reliability are your top priorities (RTO) – Use full backups with limited incrementals.
- If storage and efficiency are your main concerns – Use incremental backups with regular full backups to reset the chain.
- If disaster recovery time is critical – Keep multiple full backups readily available.
Ultimately, a backup is only as good as its ability to restore your data when you need it most. Regularly test your backups, monitor for corruption, and don't rely solely on incrementals.
