A disaster can be anything that puts an organization's operations at risk, from a cyberattack to equipment failures to natural disasters. The goal with DR is for a business to continue operating as close to normal as possible. The disaster recovery process includes planning and testing, and may involve a separate physical site for restoring operations.

The importance of disaster recovery: RPO and RTO

As businesses have become more reliant on high availability, the tolerance for downtime has decreased.

A disaster can have a devastating effect on a business. Studies have shown that many businesses fail after experiencing a significant data loss, but DR can help.

Recovery point objective (RPO) and recovery time objective (RTO) are two important measurements in disaster recovery and downtime.

RPO is the maximum age of files that an organization must recover from backup storage for normal operations to resume after a disaster. The recovery point objective determines the minimum frequency of backups. For example, if an organization has an RPO of four hours, the system must back up at least every four hours.

RTO is the maximum amount of time, following a disaster, for an organization to recover files from backup storage and resume normal operations. In other words, the recovery time objective is the maximum amount of downtime an organization can handle. If an organization has an RTO of two hours, it cannot be down for longer than that.

The RPO and RTO help administrators choose optimal disaster recovery strategies, technologies and procedures.

Meeting tighter RTO windows requires positioning secondary data so that it can be accessed faster. Recovery-in-place is one method of restoring data more quickly. This technology moves backup data to a live state on the backup appliance, eliminating the need to move data across a network. It can protect against storage system and server failure. Before using recovery-in-place, an organization needs to consider the performance of the disk backup appliance, the time needed to move data from a backup state to a live state, and failback. Since recovery-in-place can take up to 15 minutes, an organization may need to perform replication if it wants a quicker recovery time.

Preparing for a disaster requires a comprehensive approach that encompasses hardware and software, networking equipment, power, connectivity and testing that ensures DR is achievable within RTO and RPO targets. While implementing a thorough DR plan isn't a small task, the potential benefits are significant.

Disaster recovery planning and strategy

A disaster recovery plan provides a structured approach for responding to unplanned incidents that threaten a company's IT infrastructure, including hardware and software, networks, procedures and people.

The plan provides step-by-step disaster recovery strategies for recovering disrupted systems and networks to minimize negative impacts to company operations. A risk assessment identifies potential threats to the IT infrastructure; the DR plan outlines how to recover the elements that are most important to the company.