Brittle Power- PARTS 1-3 (+Notes) - Natural Capitalism Solutions

212National Energy Securityremarkably small. 109 In a typical application such as airline reservations orcontrolling a large factory, perhaps sixty percent of the cost of computing islabor. Of the forty percent that represents hardware, only a third to a half isin the computer room; the rest is communication systems and peripheraldevices (terminals, transducers, etc.). The duplexing or even triplexing ofsmall computers is relatively “inexpensive and [gives]…disproportionate reliabilityincrements.” 110 For example, while a computer using eight single diskdrives could lose one of them about eight times a year, mirrored disks (if theyfail independently of each other) reduce the rate of inoperative disk pairs toabout once per century. 111 Because the units being duplicated are small—somedesigners refer to their “granular texture”—it is much cheaper to provide backupfor them than for large, expensive units. Thus the cost of the extra hardwarein the computer room is only of the order of twenty percent. That extrahardware cost is then so diluted by other, fixed costs that NonStop reliabilityraises the total cost of computing by only about five to ten percent—far lessthan the benefits. As one of the system’s designers summarizes,[D]ecentralization may have a positive effect on both availability [being able to operate]and reliability [not making mistakes]. In a loosely coupled system, the failure ofone [component] should not affect the [others].…This localization of failures enhancesavailability. Conversely, by replicating data and programs [components]…may act asbackup for one another during periods of maintenance and failure. Lastly, decentralizationallows for modular growth of the system. When more storage or processing isneeded, it may be justified and added in small [and relatively cheap] units. 112Thus this approach offers greater security against failure and error, comparablecost of service, more reliable routine operation, 113 and greater convenienceand flexibility to the user.Dispersed processing can also make “software subversion” more difficult.If data are altered, the correct data are still stored at many other dispersed sitesand can be cross-checked and recovered intact. Any individual machine willalso probably store less information. 114 Of course, spreading the data amongmany dispersed, interconnected machines makes it easier for computer “hackers”(the equivalent of phone phreaks) to get unauthorized access and read thedata, as opposed to erasing or changing them. But this can be combated byputting the data in code. Individual privacy and corporate security will thenbe as well protected as they would be in a large computer; what matters ineither case is that the key to the code be physically secure.The key to obtaining all these benefits is the autonomy of each componentin an intercommunicating network. Each minicomputer can serve local usersin isolation even if its communication networks fail. 115 The system is therefore