In a backup strategy where a weekly full backup is performed and daily backups minimize disk usage, which backup type uses the least additional disk space for daily backups?

• A. Differential
• B. Full
• C. Incremental
• D. Copy-only

Answer: (C)

Incremental backups minimize disk space because they record only the data that has changed since the previous backup in the chain. With a weekly full backup as the baseline, each day’s backup stores just the new or modified blocks since the last backup (whether that last backup was full or incremental). That keeps the amount of data saved each day small. In contrast, differential backups capture all changes since the last full backup, so their size grows each day; a full backup stores everything again, which uses much more space; copy-only creates an extra separate copy regardless of the normal chain and can also consume more space depending on what’s copied. So, for the goal of saving disk space on daily backups, incremental is the best fit.