Differential Backup
A Differential Backup is a backup strategy that copies all data that has changed since the last full backup, regardless of how many incremental backups have occurred in between. This approach strikes a balance between full and incremental backups in terms of storage requirements and recovery complexity.
Key Characteristics
- Reference Point: Always compares to the last full backup
- Accumulating Changes: Contains all changes since the last full backup
- Simpler Recovery: Requires only the last full backup and the most recent differential backup
- Growing Size: Gets larger over time until the next full backup
Advantages
- Simpler Recovery: Faster and less complex than incremental backup recovery
- Reduced Dependency: Only depends on the last full backup
- Balanced Efficiency: More storage-efficient than full backups
- Faster Restoration: Quicker recovery compared to incremental backup chains
Disadvantages
- Growing Size: Gets progressively larger over time
- Longer Backup Windows: Takes more time than incremental backups
- Increasing Storage: Storage requirements grow until next full backup
- Less Frequent: May not be suitable for very frequent backup schedules
Best Practices
- Schedule differential backups between full backups
- Monitor backup size growth over time
- Combine with full backups at regular intervals
- Plan storage capacity for growing backup sizes
Use Cases
- Environments requiring balance between backup efficiency and recovery simplicity
- Systems with moderate change rates
- Backup strategies that prioritize recovery speed
- Hybrid backup approaches with full and incremental backups