Disaster recovery, fundamentally, means to protect business applications and data from IT downtime, which can occur for a variety of reasons (e.g., natural disaster, human error, cyber-attack). When a datacenter, or even a portion of it, is failing to serve its clients, companies are subject to lost revenue, damaged reputation, and jeopardizing industry-specific credentials (e.g., financial, healthcare). Ideally, clients would be unaffected during datacenter outages; however, ensuring pristine business continuity is difficult and expensive, so companies have to strike a compromise between performance and cost. For example, not every company has the budget to provide synchronous replication of applications and data to support a zero-data-loss disaster recovery (DR) plan.
Why is DRaaS Useful?
A cost-effective alternative for an increasing number of companies is to opt for a managed service for their DR needs. Cloud-based DRaaS boasts the majority of the core capabilities a large budget enterprise might enjoy, but at a fraction of the cost and with a much faster time to value. The typical trade-off is with recovery point objective (RPO) and/or recovery time objective (RTO), where an on-prem DR solution might approach RPO and RTO of zero, DRaaS solutions tend to be on the order of hours, or at best, minutes for each metric. For most companies, this is acceptable. As a result, DRaaS tends to appeal to companies that can withstand moderate data loss with the benefit of much lower TCO.
The standard service model for DRaaS is a baseline subscription that is tied to a service level agreement (SLA) the service provider (SP) is contractually bound to. Some SPs also meter ingress and egress traffic and tack on additional charges, based on usage. The DRaaS datacenter essentially becomes the DR target for a company’s on-prem applications and data. Once a relationship is in place, a VPN is pinned up between the customer and SP datacenter, and application snapshots are replicated to the DRaaS datacenter based on required RPO metrics. In the event of a datacenter outage, failover to the DRaaS datacenter is initiated and business operations are restored in compliance with the SLA.
Advantages of DRaaS
A good DRaaS solution includes failover/failback testing during normal business hours, without impacting the mainstream client experience. It also includes the otherwise difficult task of preserving network configurations upon failover so that IP readdressing is not necessary. Lastly, a common management interface that spans the entire enterprise simplifies operation tasks, making such a DRaaS solution stand out from its peers.