If you are creating or updating your disaster recovery plan, knowing your RTO and RPO is fundamental. The first step in DR planning is to establish what you need to protect and to set priorities. All data is not created equal and it is highly probable that there is no good reason to replicate and store every bit and byte on your servers and storage.
The two most important factors that are used to measure the criticality of IT systems are 1) how much data can you afford to lose and 2) how much time can you can afford to lose before services resume.
Recovery Point Objective (RPO)
The first factor, the Recovery Point Objective, is determined by how much data you can afford to lose since it was last backed up. Determining your organisation’s RPO usually begins with examining how frequently backup takes place. Since backup can be an intrusive to systems and IT services, they are not typically performed more frequently than several hours apart at best. This means that your backup RPO is probably measured in hours of data loss.
Recovery Time Objective (RTO)
The second factor, the Recovery Time Objective is determined by how quickly you need to have an IT service’s information restored and available for use. For example, four hours, eight hours, or the next business day may be tolerable for an e-mail system. As well as restoring data, RTO should consider the amount of time it takes to provision new servers, storage, network resources and virtual machine configurations.
By using these two principle measures, it will help you understand your cost of downtime, help define a budget for an IT system continuity plan and determine the technology that best meets your needs within your budget.
Choosing DR Solution
Finding the right balance of features and price to meet your RPO and RTO requirements is one of the most critical things you can do to protect your business data. For IT service continuity, there are three solution categories: backup, disaster recovery and high availability.
- Backup means keeping your data safe; in this situation, RPO is more critical than RTO.
- Disaster recovery is the ability to recover data if the production system is damaged, destroyed or becomes unavailable for an undeterminable period of time. A comprehensive disaster recovery solution that can restore data quickly and completely is required to meet low RPO and RTO thresholds.
- High availability means keeping your critical applications and data online – a high availability solution, such as MIMIX is required for high RPO and RTO.