Computer Associates ARB6002700WF0. ..... Administration Guide - Page 53

Planning for Catastrophe Assessing the Risk Before going further, decide what sorts of disaster you can realistically prepare for, given the importance of your data, the expense of protecting it, the magnitude of the risk, and the corporate policies that apply to your sites. Consider the following questions. ■ What is the likelihood that your organization will face a large-scale disaster that affects the whole region or metropolitan area? Such catastrophes might include earthquakes, large floods, or acts of war. ■ What is the likelihood of smaller disasters, such as building fires, localized flooding, or vandalism? ■ How much data would you lose in a large disaster? In a small disaster? ■ How severely would the loss affect your organization in each case? ■ How much is your organization prepared to spend to defend against each of the risks you identify? Selecting an Off-site Repository Like everything else in storage management, the selection of an off-site repository or vault is the result of a series of trade-offs. Security The vault should be isolated enough from your main facility to protect the off-site data from the kind of catastrophes you are prepared to guard against. If earthquakes are the biggest threat you need to deal with, the vault should be in an earthquake-resistant building at some distance from your main site or even in another city or a different seismic zone. On the other hand, if fire or local flooding is the danger, a storage room in an upper floor of the building across the street might be enough. Accessibility Unfortunately, measures that isolate your data repository from your primary site also make it harder (and more expensive) to keep the data in the remote repository current. To be of use, off-site data has to be reasonably up-to-date, which means it has to be reasonably accessible. A vault in a distant city might protect the data against even the most extreme disasters, but it might be impractical to ship media there on a daily basis. Planning 2-15