220-1102 Question 693
Single answerIncrementalA small business backs up a file server every Sunday night with a full backup and runs incremental backups Monday through Thursday. Early Friday morning, a drive fails and the technician must restore the server to its most current state using the backup set. Which backup media are required to complete the restore?
- A
Only Thursday night's incremental backup
- B
Sunday night's full backup and Thursday night's incremental backup
- C
Sunday night's full backup and every incremental backup from Monday through Thursday
- D
The most recent differential backup and Sunday night's full backup
Show answer and explanation
Correct answer: C
Explanation
Incremental backups are designed to save storage space and reduce backup time by copying only data that has changed since the most recent backup, whether that prior backup was full or incremental. The tradeoff is longer and more complex restores. In this scenario, restoring to the most current state requires the Sunday full backup followed by each incremental backup from Monday, Tuesday, Wednesday, and Thursday in sequence. This aligns with standard backup best practices and common IT training guidance: full backups are easiest to restore from, differential backups simplify restores by requiring only the full plus the latest differential, and incremental backups minimize backup time and storage but require the full backup and the complete incremental chain for recovery.
- A. Incorrect.
Incorrect. An incremental backup contains only the data changed since the last backup of any type, not the entire dataset. Restoring from only Thursday night's incremental backup would omit files changed earlier in the week and any data that existed only in the full backup.
- B. Incorrect.
Incorrect. This is a common confusion between incremental and differential backups. With incrementals, each backup depends on the previous backup chain. Thursday's incremental includes only changes since Wednesday's backup, so the Monday through Wednesday incrementals are also needed.
- C. Correct.
Correct. To restore from a backup strategy that uses a full backup followed by incremental backups, the technician needs the last full backup plus every incremental backup created after it, in order. This is because each incremental captures only the changes since the previous backup.
- D. Incorrect.
Incorrect. A differential backup is a different backup type. Differential backups contain all changes since the last full backup, but the scenario specifically states that Monday through Thursday used incremental backups. Therefore, there is no differential backup to use, and this option does not match the backup plan described.