This strategy involves one full backup per week and daily backups of only the data that has changed since the last backup of any kind. This makes the daily (weekday) backup process extremely fast and minimizes storage consumption, as each incremental file only contains a single day's changes. However, for a full restoration, one must apply the last full backup and then every single subsequent incremental backup in the correct order. This multi-step process is significantly more complex and time-consuming than restoring from differential or full backups, thereby resulting in the longest restore time.

A. Full weekly backup with daily differential backups.

A differential backup saves all changes since the last full backup, causing backup time and storage to grow each day. Restoration is faster, requiring only the full and the latest differential backup.

B. Mirror backups on a daily basis.

A mirror is a direct copy of the source data. The backup time is long (similar to a full backup), and the restore process is very fast, which contradicts the question's requirements.

C. Full backups on a daily basis.

This method has the longest daily backup time, consumes the most storage space, and offers the fastest possible restore time, directly opposing all three conditions specified in the question.

1. National Institute of Standards and Technology (NIST) Special Publication 800-34 Rev. 1

Contingency Planning Guide for Federal Information Systems.

Section 3.4.2

Data Backup Strategies

Page 28: This document describes an incremental backup as copying "all files that have been changed since the last full or incremental backup." It explicitly states

"This method uses the least amount of media and is the fastest method for backing up." It also details the complex restoration process: "restoration requires the last full backup and all incremental backups since the last full backup." This confirms the long restore time.

2. University of Washington

IT Connect

Types of Backup.

Section: Incremental Backup: This university resource clearly outlines the trade-offs. Under "Pros

" it lists "Fastest backup" and "Uses least storage space." Under "Cons

" it states "Slowest restore" because "the last full backup and all subsequent incremental backups are needed." This directly supports all three elements of the question.

3. Limoncelli

T. A.

Hogan

C. J.

& Chalup

S. R. (2017). The Practice of System and Network Administration

Volume 1: DevOps and other Best Practices for Enterprise IT (3rd ed.). Addison-Wesley Professional.

Chapter 22.4.2

Backup Types

Pages 538-539: This standard academic and professional text explains that incremental backups are the fastest to perform. It contrasts this with the restoration process

stating

"To restore a filesystem

one must restore the last full dump and then every incremental dump since then

in order." This highlights the lengthy and complex nature of the restore.