Comparing full, incremental and differential backups

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. To restore from an incremental backup strategy, which is needed?

A The last full backup plus every incremental backup since it

B The last full backup plus only the most recent incremental backup

2. To restore from a differential backup strategy, which is needed?

A The last full backup plus every differential backup since it

B The last full backup plus the latest differential backup

3. Which backup type uses the MOST storage space over a week?

A Full backup, because it copies all data every time

B Incremental backup, because it copies all data every time

4. Which backup type is usually the quickest to run each night?

A Differential, because it saves only changes since the last backup

B Incremental, because it saves only changes since the last backup

5. Which statement about differential backups is correct?

A They grow larger each day until the next full backup

B They stay the same small size every day

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1Full backup		AFull backups use the most storage and time. Incremental backups after a weekly full backup suit limited storage and a short window.
2Incremental backup		BCopies only data changed since the last backup of any type. It is the smallest and fastest, but a restore needs the full backup plus every incremental in order.
3Differential backup: copies everything changed since the last full backup, so each one grows larger during the week		CCopies all selected data every time. It is the largest and slowest backup, but a restore needs only this one backup.
4Restoring after a Thursday crash with a Sunday full backup and daily differentials needs only 2 backups		DMon Full, Tue Diff (Mon changes), Wed Diff (Mon+Tue changes), Thu Diff (Mon-Wed changes)
5Restore from incrementals: use only the latest incremental backup, because it holds all the changes		ERestore: Sunday Full + Wednesday Differential
6A small business with limited storage and a short backup window should run a full backup every night		FAn incremental holds only changes since the previous backup. You must restore the last full backup plus every incremental in order.

Definitions

full vs incremental vs differential

Fill in the Blanks

Complete each line of code by filling in the missing parts.

Full: copies ___ selected data every time

Incremental: saves changes since last ______

Differential: saves changes since last ____

Full + latest differential = _ backups

Fastest backup, slowest restore: ___________

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A Sun: FULL backup (all files)

B Mon: INCR (all files copied)

C Tue: INCR (changes since Mon)

D Restore Tue: Sun + Mon + Tue

Question 2

A Full backup copies changes only

B Restore needs only 1 backup

C It is the slowest to create

Question 3

A Differential backup:

B - changes since last backup

C - restore: full + latest diff

Question 4

A Sun: full backup

B Mon: differential

C Fri: differential

D Restore: full + all diffs

Question 5

A Storage use per backup:

B Full: largest every time

C Incremental: same size as full

D Differential: grows each day

Answer Key

Comparing full, incremental and differential backups

Section A: Quick Questions

A — The last full backup plus every incremental backup since it

B — The last full backup plus the latest differential backup

A — Full backup, because it copies all data every time

B — Incremental, because it saves only changes since the last backup

A — They grow larger each day until the next full backup

Section B: Match the Pairs

Full backup → Copies all selected data every time. It is the largest and slowest backup, but a restore needs only this one backup.

Incremental backup → Copies only data changed since the last backup of any type. It is the smallest and fastest, but a restore needs the full backup plus every incremental in order.

Differential backup: copies everything changed since the last full backup, so each one grows larger during the week → Mon Full, Tue Diff (Mon changes), Wed Diff (Mon+Tue changes), Thu Diff (Mon-Wed changes)

Restoring after a Thursday crash with a Sunday full backup and daily differentials needs only 2 backups → Restore: Sunday Full + Wednesday Differential

Restore from incrementals: use only the latest incremental backup, because it holds all the changes → An incremental holds only changes since the previous backup. You must restore the last full backup plus every incremental in order.

A small business with limited storage and a short backup window should run a full backup every night → Full backups use the most storage and time. Incremental backups after a weekly full backup suit limited storage and a short window.

Section C: Definitions

full vs incremental vs differential — They differ in size, time and restore steps: full copies all data, incremental saves changes since the last backup, differential saves changes since the last full backup.

Section D: Fill in the Blanks

Full: copies all selected data every time

Incremental: saves changes since last backup

Differential: saves changes since last full

Full + latest differential = 2 backups

Fastest backup, slowest restore: incremental

Section E: Spot the Error

B — An incremental backup copies only the changes since the last backup of any type. Line 2 should say 'changes since Sun', not 'all files copied', which describes a full backup.

A — A full backup copies all the data every time. Copying only changes describes incremental or differential backups.

B — A differential backup copies everything changed since the last FULL backup, not since the last backup of any type. 'Since the last backup' describes an incremental backup.

D — Each differential holds all changes since the last full backup. A restore needs only the full backup plus the latest differential (Fri), not every differential.

C — Each incremental backup holds only the changes since the previous backup, so it is usually the smallest. It is not the same size as a full backup.