week 21

K1.21 The purpose, criteria and types of back-up involved in risk mitigation:

To maintain an up-to-date copy of data that can be used to restore systems or information in the event of:

• Full disaster recovery (e.g. flood, ransomware attack)

• Partial data loss (e.g. accidental deletion, corrupted file)

Back-ups help organisations recover quickly and continue operating with minimal disruption.

Back-Up Criteria

When designing a back-up strategy, organisations must consider the following key criteria:

The more frequent and reliable the back-up, the less data the organisation will lose in a disaster.

Types of Back-Up

Organisations use different types of back-up depending on how much data they have, how often it changes, and how fast they need to recover.

Full Back-Up

A complete copy of all selected data is made every time a back-up is run.

Best for weekly back-ups or before big changes.

Incremental Back-Up

Only backs up data that has changed since the last back-up (whether full or incremental).

✅ Good for daily/hourly back-ups where storage space is limited.

Differential Back-Up

Backs up all changes made since the last full back-up (ignores previous differential back-ups).

Balances speed and space — often used mid-week between full back-ups.

Mirror Back-Up

Creates an exact real-time duplicate (mirror) of the source data.

Ideal for systems that require near-zero downtime (e.g. financial services).

Example Scenario

A college IT department backs up student data as follows:

• Sunday: Full back-up to cloud

• Monday to Friday: Incremental back-up to network-attached storage (NAS)

• Every hour: Mirror back-up of assessment system for real-time restoration

This layered strategy balances storage, recovery speed, and security.

Design a Back-Up Strategy

Scenario:
You are responsible for designing a back-up solution for a small business that uses cloud systems, in-house servers, and allows remote work.

Task:
1. Choose a combination of back-up types (e.g. full + incremental).

2. Decide on:
  - Frequency of each back-up
  - Source data (files, systems, email)
  - Destination (e.g. cloud, external hard drive)
  - Storage method (e.g. LTO, disk)

3. Justify why your strategy will protect the business in case of:
  - Accidental deletion
  - Cyberattack
  - Hardware failure

Extension: Create a diagram to visually show the back-up schedule.

Last Updated
2025-07-14 13:40:19