What is disaster recovery (DR)?
Disaster recovery (DR) is the set of policies, tools and procedures a company uses to restore its critical systems and data and get back to operating after an event that takes it down: a cyberattack, a hardware failure, a human error or a natural disaster. It is the recovery half of business continuity. While backup keeps the copy, disaster recovery is the tested plan that turns that copy back into a working operation, within a defined time (the RTO) and with an acceptable amount of data loss (the RPO).
How a disaster recovery plan is built
Disaster recovery is not a product you buy, it is a discipline you plan. A good plan runs from the business to the technology, in four steps.
Map what is critical
Before any technical decision, a business impact analysis lists which systems are critical, in what order to bring them back and how much downtime the company can tolerate (the MTPOD). Not everything comes back first, and it is the business, not IT, that sets the queue.
Set RTO and RPO per system
For each system, the plan fixes two targets: how fast it must come back (the RTO) and how much data can be lost (the RPO). Those two numbers say how much protection each system deserves and how much it costs to deliver it.
Choose and provision the recovery strategy
With the targets in hand, you decide how to recover: restore from backup, keep a standby environment already up, or buy recovery as a service (DRaaS). Systems with a short RTO need a standby always ready; less critical ones can wait for a restore.
Test, document and keep it alive
A plan never tested is an assumption. Periodic drills prove the recovery fits the RTO, reveal what is missing and keep the steps valid as the company changes. It is the most skipped step and the one that most decides the outcome.
Source: NIST SP 800-34 (the official contingency planning guide), N-able continuity material and 2025 market reports (Uptime Institute, Cutover, IBM).
The kinds of disaster a plan covers
- Cyberattack Today the leading disruptive threat. Ransomware that encrypts servers and wipes backups can stop the company for days, and it is the scenario that most tests how fast recovery really is.
- Hardware or infrastructure failure A server that dies, storage that corrupts, the network or the power that goes down. Technical failure gives no warning and strikes at any hour.
- Human error The most underrated scenario. A deleted file, a wrong setting or a botched update takes systems down with no attacker at all, and it is one of the most common causes of recovery day to day.
- Natural or physical disaster Fire, flood, an extended power outage or a building problem make the primary environment unreachable, even with every device intact.
- A third-party or cloud failure A cloud provider, a SaaS or an essential supplier going offline takes your operation with it. Relying on third parties does not remove the need for a plan, it only changes who has to run it.
Why a disaster costs more than you think
A disaster rarely warns you, and the loss is not the equipment, it is the stopped hours. One in five major outages costs the company more than $ 1 million, and more than half top $ 100,000 (Uptime Institute, 2024). The problem is that almost everyone believes they will recover, and few can prove it: only 64% of recovery targets for critical systems are actually met, meaning more than a third do not come back within the deadline the company itself set (Cutover, 2025). The cause is usually the same: the plan exists on paper but was never rehearsed, the standby environment was not ready, and recovery ended up assembled in a rush at the worst moment. With a breach costing an average of $ 4.44 million (IBM, 2025), the gap between a tested plan and a hope gets expensive, and it is usually measured in hours of lost revenue.
How to make disaster recovery actually work
The difference between a plan that saves you and one that fails comes down to five simple habits, almost always neglected.
- Do not confuse backup with recoveryHaving a copy is not having a plan. The right question is not “do we back up?”, it is “have we already proven we can get back to operating, and how fast?”.
- Set RTO and RPO and write down the stepsFor each critical system, define how fast it comes back and how much data can be lost, and record who does what, in what order and with which access. A plan in one person's head is not a plan.
- Protect the copy itself with immutable backupIf ransomware wipes the backup along with the data, there is no recovery. A copy that cannot be altered or deleted is the ground everything else stands on.
- Rehearse recovery as if it were todayTest at least once a year, and quarterly on the most critical systems, measuring the result against the RTO. The drill is what reveals the cheap failure before it turns into an expensive loss.
- Make sure someone runs it at the worst momentA disaster does not keep business hours. Having a team or an on-call service to run the recovery keeps the plan from depending on one person being available at the wrong time.
In practice
Backup answers one question; disaster recovery answers another, more expensive one. Backup says whether the data came back. Disaster recovery says whether the company came back to operating, and how fast. The distance between the two comes down to one detail almost no one does: testing the plan before you need it.
How Zamak handles disaster recovery
Zamak Technologies treats disaster recovery as a proven capability, not a document in a drawer, and works alongside your team: it maps what is critical, sets RTO and RPO per system, keeps the copy protected against tampering with immutable backup and a standby environment ready to take over, and runs the tests that prove recovery fits the defined deadline. That way, if the worst happens, the question “how long until we are back?” already has a rehearsed answer. To size the cost of an outage and the RTO that pays off, start with the downtime cost calculator. It is part of Continuity in the Zamak Method.