Disaster Recovery Planning: RTO, RPO and Backups Explained

Ransomware, a failed storage array, a fire or a simple mistake by an administrator can stop a business in minutes. Disaster recovery planning decides how quickly you get back up and how much data you lose when that happens. This guide explains the two numbers that matter most, RTO and RPO, how to build a backup strategy around them, and how to test that it actually works.

Disaster recovery vs business continuity

The two are related but different. Business continuity is the wider plan for keeping the organisation running during a disruption: people, offices, suppliers and communication. Disaster recovery is the IT part of that plan: restoring systems, applications and data. You need both, and the IT plan should be built from the business priorities, not the other way around.

RTO and RPO: the two numbers to agree first

• Recovery Time Objective (RTO): how long a system can be down before the impact becomes unacceptable. An online trading platform might need an RTO of minutes; an archive server might tolerate two days.
• Recovery Point Objective (RPO): how much data you can afford to lose, measured in time. An RPO of one hour means backups or replication must capture changes at least every hour.

Agree RTO and RPO for each important system with business owners. Shorter targets cost more, so it is normal to have tiers: a few critical systems with near-zero targets, and the rest with hours or a day.

Building a backup strategy for disaster recovery

A widely used starting point is the 3-2-1 rule: keep three copies of your data, on two different types of storage, with one copy offsite. Today we recommend going further:

• Immutable or offline copies: backups that cannot be changed or deleted, even by an administrator, so ransomware can't destroy them.
• Separate credentials: backup systems should not share admin accounts with production.
• Encryption: protect backups in transit and at rest.
• Retention: keep enough history to recover from problems discovered late, such as slow data corruption.

Choosing a disaster recovery site

Backups protect data; a recovery site restores service. The main options are a secondary data centre, a cloud-based recovery environment, or Disaster Recovery as a Service, where a provider keeps replicas of your systems ready to start. Cloud-based recovery has made short RTOs affordable for mid-size businesses, because you pay mostly for storage until you actually need to fail over. If you are moving workloads anyway, our cloud migration checklist shows how to build recovery in from day one.

Writing the disaster recovery plan

1. List critical systems with their RTO, RPO, owners and dependencies.
2. Document step-by-step recovery procedures that someone other than the usual administrator could follow.
3. Define who declares a disaster and how staff, customers and regulators are informed.
4. Keep contact lists and the plan itself available offline.

Test, test and test again

An untested plan is only a hope. Run tabletop exercises to walk through scenarios, restore individual files and full servers regularly, and perform a full failover test at least once a year. Record how long each step took, compare it with your RTO and fix what was slow. Many organisations discover during their first test that a backup was incomplete or that a key password was missing.

Quick disaster recovery checklist

• RTO and RPO agreed and signed off for every critical system.
• At least one immutable or offline backup copy.
• Recovery steps written down and stored offline.
• A full restore tested in the last twelve months.
• Clear decision-makers and a communication plan for staff and customers.

How TM Solutech helps

We assess your current setup, agree RTO and RPO with your teams, design backup and recovery on-premises or in the cloud, and run recovery tests with you. Explore our business continuity and disaster recovery services or talk to an expert.