When Hurricane Ike struck last summer, many feared a repeat of the 2005 Katrina catastrophe. While Ike turned out to be one of the most destructive hurricanes on record, its impact was nowhere near as devastating as Katrina's. This was due, In part, to better preparedness across the board.
From an IT perspective, Katrina raised the level of consciousness regarding disaster recovery (DR) and spurred more organizations to invest in "recoverability."
However, building a DR capability, particularly in the current economic climate, can still be a tough sell. The business justification for DR is based primarily on risk avoidance -- a so-called soft metric -- rather than on hard cost savings. In addition, DR implementations often involve an investment in infrastructure that mostly sits idle waiting for that fateful day. As a result, organizations may be tempted to shelve DR initiatives or re-prioritize them further down the IT project stack.
Unfortunately, disasters don't distinguish between good and bad economic times. But you could easily argue that preparedness in tough times is even more critical as institutions are less able to tolerate instability.
Disaster recovery is an insurance policy and, as with any other type of insurance, we dislike the possibility of paying for something
When it comes to storage-related DR services, many organizations fall into one of two categories:
- One size fits all. There's a single service option, which is often tape-based recovery. For mid- to large-sized organizations, it's highly unlikely that all application needs can be adequately met with a single solution; it's too much for some and not enough for others.
- Two sizes fit all. In addition to tape, a data replication option exists. While this may be adequate in some cases, we've encountered situations where the gap between the two services levels -- tape-based recovery vs. synchronous replication, for example -- is simply too large. This forces a choice between a very high cost option that more than meets requirements or a much less-expensive one that falls short.
It's important for an organization to develop a catalog of DR services that can address the required range of recovery time objective (RTO) and recovery point objective (RPO) requirements at appropriate cost differentials to avoid over-delivery.
This top-down approach of gathering business requirements to formulate a strategy must then be tempered with a bottom-up understanding of the "step-function" cost implications of various protection options. The iterative process of testing assumptions and validating business needs against the likely cost to meet those needs results in a more realistic stratification of requirements from which we can develop a DR service catalog that aligns efficiently with the business.
This was first published in February 2009