A server administrator was asked to implement a site backup solution. The backup window during regular business days is from midnight to 6:00 a.m. because end-of-cycle payroll processing will occur…

Incremental backups are the shortest individual sessions but require every incremental set plus the last full backup for restoration, increasing recovery complexity over a three-month chain.

A full backup copies all data every night, making it the longest possible backup job and unlikely to fit consistently within a 6-hour window.

A differential backup copies only data changed since the last full backup, meaning each nightly session is significantly shorter than a full backup and comfortably fits within the 6-hour window. Over the three-month payroll period, differentials grow gradually but never reset to zero like incrementals do after each run, keeping restore complexity low while maintaining short backup windows. This makes differential the best balance of short backup duration and operational reliability.

A normal backup is synonymous with a full backup and shares the same drawback of backing up all data nightly, which is too time-consuming for the restricted window.