-----Original Message----- From: David Boyes Sent: Fri 8/3/2007 6:00 AM To: [EMAIL PROTECTED] Cc: David Boyes Subject: Distance between primary and DR site If you can't afford (or your bosses are too cheap) to do a full risk study, I use what I call the Greek Elements model:
Consider the classical Greek elements: Earth, Air, Fire, and Water, plus the modern element, plasma. A good general ROT is that your DR site should be no closer than 2.5 times the diameter of the largest possible disaster that could occur in the area. If there are earth problems (quakes, slides, etc), your backup center should be at least 2.5 times the distance from the center of the last major problem. If there are wind problems (high winds, tornados, etc), you should be at least 2.5 times the diameter of the largest storm destruction area recorded. If there are fire problems in the area, you should be at least 2.5 times the distance of the diameter of the largest fire recorded in the area. If there was water nearby, you should be at least 2.5 times the width of the body of water. To avoid nuclear burst areas (the plasma element), assume 100 mile burst radius, and apply the 2.5 rule. If there are multiple hazards, the rule applied should reflect the largest hazard. Example: if the area gets hurricanes with storm tracks of 100 miles in diameter, your DR center should be no closer than 250 miles away. If your area gets tornadoes with 10 mile destruction paths, your DR center should be no closer than 25 miles away. If there is a dam on a lake 5 miles away, your DR center should be no closer than 12 miles away. Never failed me yet. (I really liked the "at least 50 megatons distance" response...) ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html