3-4-4 Backup and Recovery Explained

Key Concepts

• Backup Types
• Backup Strategies
• Recovery Procedures
• Data Integrity
• Backup Media

Backup Types

Backup types include:

• Full Backup: Copies all selected data.
• Incremental Backup: Copies only data that has changed since the last backup.
• Differential Backup: Copies all data that has changed since the last full backup.
• Synthetic Full Backup: Combines incremental backups to create a full backup without reading from the original data.

Backup Strategies

Common backup strategies include:

• Full Backup with Incremental: Combines a full backup with incremental backups for efficiency.
• Full Backup with Differential: Combines a full backup with differential backups for quicker recovery.
• Grandfather-Father-Son: Uses a hierarchy of backups to manage retention and recovery.

Recovery Procedures

Recovery procedures involve:

• Restoring from Full Backup: Uses the most recent full backup to restore all data.
• Restoring from Incremental Backup: Requires the most recent full backup and all subsequent incremental backups.
• Restoring from Differential Backup: Requires the most recent full backup and the most recent differential backup.

Data Integrity

Data integrity ensures that backups are accurate and complete. Techniques include:

• Checksum Verification: Uses mathematical checksums to verify data accuracy.
• Data Validation: Tests backups to ensure they can be successfully restored.
• Encryption: Protects data during backup to prevent unauthorized access.

Backup Media

Common backup media include:

• Tape Drives: Cost-effective for large-scale backups.
• External Hard Drives: Portable and easy to use.
• Network Attached Storage (NAS): Provides centralized storage for backups.
• Cloud Storage: Offers scalable and offsite backup solutions.

Examples and Analogies

Think of backup and recovery as creating multiple copies of a book. A full backup is like having a complete copy of the book. An incremental backup is like adding new chapters as they are written. A differential backup is like adding all new chapters since the last full copy. Recovery is like putting all the chapters together to read the complete book.

Another analogy is a treasure chest. Full backup is like having a complete set of treasure. Incremental backup is like adding new treasures as they are found. Differential backup is like adding all new treasures since the last full set. Recovery is like gathering all the treasures to enjoy the full collection.