Why it matters
Things will break: disks fail, someone deletes the wrong folder, a dependency has a security hole, a region has an outage. Employers trust engineers who plan for failure and stay calm when it comes. Ghanaian infrastructure adverts name disaster recovery, backups and security standards, and banks and telcos treat them as essential. This builds on backups and security basics from IT support and security from backend.
Backups you have actually tested
A backup you have never restored is a hope, not a backup. The three copies rule still applies in the cloud: keep at least three copies of important data, on two kinds of storage, with one copy somewhere else, such as another region or account. Then restore regularly into a test environment and check the data is complete.
Two questions shape a backup plan:
- Recovery point objective (RPO): how much recent data can we afford to lose? If backups run nightly, up to a day.
- Recovery time objective (RTO): how long can we be down while restoring?
A bank's payments system needs both close to zero; a school newsletter can accept much more.