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📖 What is Differential Backup?

A backup that includes all data that has changed since the last full backup.

🥋 Sensei Says:

"Grows in size until the next full backup, but faster to restore than incrementals (only need Full + 1 Differential)."

📚 Certification: Certified in Cybersecurity (CC)

🔑 What are the Key Concepts of Differential Backup?

▸ Differential backups capture all changes made since the *last full* backup, increasing in size with each subsequent differential.
▸ Restoring from a differential backup requires the last full backup *and* the most recent differential backup – a two-step process.
▸ Compared to incremental backups, differential backups take longer to create but are faster to restore due to fewer backup sets.
▸ Understanding the trade-off between backup speed, storage space, and restore time is crucial for choosing the right backup strategy.
▸ Differential backups are commonly used in conjunction with full backups to provide a balance between data protection and efficiency.

🎯 How does Differential Backup appear on the CC Exam?

You may be asked to determine the optimal backup strategy for a database server, considering recovery time objectives (RTO) and recovery point objectives (RPO).

A scenario might describe a system failure and require you to identify the necessary backup sets to restore the system to its last known good state, given a full and several differential backups.

Expect questions about calculating the total time required to restore a system using a full backup and the latest differential backup compared to other backup methods.

❓ Frequently Asked Questions

How does a differential backup differ from an incremental backup in terms of restore time?

Incremental backups require restoring the full backup *plus* every incremental backup since then, making restore times longer. Differential only needs the full and the *latest* differential.

If I take a full backup every week, and differential backups daily, how does that impact storage requirements?

Storage grows linearly each day until the next full backup. While efficient, differential backups consume more space than incremental backups over time, especially with frequent changes.

Can differential backups be used for disaster recovery?

Yes, but consider the restore time. While reliable, restoring a large differential backup can take significant time, impacting RTO. Test your restore process regularly to validate recovery times.

Related Terms from Certified in Cybersecurity

Asymmetric Encryption Separation of Duties Disaster Recovery Plan (DRP) Accountability IDS (Intrusion Detection System) DMZ (Demilitarized Zone)

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