A remote site as such should not be powered by the same electric plant It should not be using the same telephone exchange connections or the same fiber trunk. Its access should not be using the same airport or railway or road This access should be possible in the event of a earthquake or a social strike or whatever ( a quarantine because of a disease for example). Under all these considerations, analysis and recomendations ( Bale II for example) are pointing to distance of at least 100 miles but it depends of your primary location mainly. This distance is one of the reason why we cannot use Parrallel sysplex with data sharing without suffering response time problems. Under such restrictions, it is wise to use 2 sites under 8 km ( 5 miles ) distance and a third one at 200 km ( of course the 8km or 10km for sysplex can be slightly more and I do not intend to argue about, but it definitely never is a safe distance)
I normally see these distances accepted only by the ones who had burnt their fingers for not respecting them. Bruno Sugliani zxnetconsult(at)free(dot)fr On Wed, 23 Jun 2010 14:48:06 +0000, john gilmore <[email protected]> wrote: >Ed Finnell has just made the important point that these sites should be separated by at least 10 miles (16 kilometers). > > > >Sometimes this magic number needs reconsideration. The right value may be 30 or 50 miles (48 or 80.5 km). A shop located in the rural American Midwest may, for example, need a more remote DR site because one so close would be too likely to suffer hurricane damage in the same incident or lose power for the same reason. > > > >A client recently had such a problem, about which I had warned it; but I was not happy to have my reputation as a Cassandra confirmed again. > > >John Gilmore Ashland, MA 01721-1817 USA > > > >_________________________________________________________________ >The New Busy is not the too busy. Combine all your e-mail accounts with Hotmail. >http://www.windowslive.com/campaign/thenewbusy?tile=multiaccount&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_4 >---------------------------------------------------------------------- >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 ---------------------------------------------------------------------- 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
