Recovery is a necessary balance to availability

Many IT vendors and continuity providers offer their customers IT service continuity solutions with promises of systems that provide such high levels of hardware availability, that the companies feel it is unnecessary to include recoverability in their plans. After all, with 99.999% availability guaranteed, who is going to complain about five minutes of downtime per year?

"While it is true that the availability of IT systems has advanced to levels where critical hardware services can be guaranteed to be available for 99.999% of the time, assuming this covers all the aspects of IT service continuity is a mistake," says Bradley Janse van Rensburg, solutions design manager at ContinuitySA.

"Technology failure is the result of more than simply hardware glitches and it only takes one unexpected event, such as human error, to send a system down. If this happens and you have no recovery plans, your company is at risk.

"Unlike hardware, human error is impossible to predict. Availability promises are therefore made according to known, not all, possible faults and this vulnerability needs to be acknowledged in continuity planning."

This is why availability needs to be balanced by recoverability. Availability reduces the likelihood of system failure; but recoverability reduces the impact of unexpected failure.

IT recovery simply means calculating the impact your business will face without its computer systems and formulating a plan to bring critical systems back online within a prescribed period. As opposed to the ability to automate availability processes, recoverability needs to be initiated and is essentially a human decision executives or senior managers of the organisation will have to make.

To be able to initiate an effective recoverability strategy in case of a disaster, the pertinent questions to ask are:

* How long will we be down for?
* How much information will we lose?
* Will we have degraded performance, and if so, on which systems?
* Will we be able to elegantly role back to production, and when?

"Answering these questions will empower the crisis management team to assess the situation and make the appropriate recovery decision," explains Janse van Rensburg. "We must always remember we are dealing with the real world and systems designed by humans, into which errors will creep. And while we can predict potential hardware failures and mitigate against these successfully to ensure high-availability systems, availability does not replace the need for carefully planned recoverability services.

"Recoverability takes care of the unknown and is dependent on people having the right data and doing the necessary preparation to deal with the unexpected in a planned manner to obtain a predetermined outcome, in other words, fully functional critical systems when the primary infrastructure is down."

Click here to view the graph included in this Continuity SA press release.