Which statement about backups is true?

Which statement about backups is true?

• A. The last backup does not necessarily have to be a full backup
• B. The last backup must be a full backup
• C. Incremental backups copy all data since the beginning of time
• D. Differential backups require a full backup before every operation

Answer: (A)

Backups are built around a baseline copy plus subsequent backups that capture only changes since the previous backup. Because of that, the most recent backup in a sequence doesn’t have to be a full backup. A common pattern is a full backup on a schedule (like weekly) with incremental backups on the days in between. When you restore, you start from the latest full backup and then apply the later backups in order. If the last backup is incremental, you apply all the incremental backups since that full backup; if the last backup is differential, you apply the latest differential on top of the full backup. So the statement is true. Incremental backups copy only data changed since the last backup (not since the beginning of time), while differential backups copy data changed since the last full backup. A single full backup serves as the baseline for all differentials, so you don’t need a new full backup before every differential.

Backups are built around a baseline copy plus subsequent backups that capture only changes since the previous backup. Because of that, the most recent backup in a sequence doesn’t have to be a full backup. A common pattern is a full backup on a schedule (like weekly) with incremental backups on the days in between. When you restore, you start from the latest full backup and then apply the later backups in order. If the last backup is incremental, you apply all the incremental backups since that full backup; if the last backup is differential, you apply the latest differential on top of the full backup. So the statement is true.

Incremental backups copy only data changed since the last backup (not since the beginning of time), while differential backups copy data changed since the last full backup. A single full backup serves as the baseline for all differentials, so you don’t need a new full backup before every differential.