Back in the early days of home computing (think '70s), Byte magazine pushed 'paper bytes'. A way to print bar codes on full sheets of paper that could be scanned back in easily (even by light pen, one bit at a time). Their idea (pre-internet) was to use it to allow publishing of both binary and source code in paper form that could be easily put into home computers (and even duplicated with copiers without expensive floppy media - CD and DVD were not an issue at the time).
Archival media in CD and DVD form are still 'not there yet'. Non-acid paper kept in reasonable conditions can easily last hundreds of years. Magnetic media don't hold up well to time, and we change technologies so often, we keep 'upgrading' before the last of the previous technology dies... but such is how evolution works. The Byte Magazine Paper Bytes idea is still good, just not high density enough to work for us today. People have mused about using lasers to etch into mineral substrates (a stronger/better, less prone to degradation media than DVDs or CDs - even 'archival grade media', but I have yet to hear of any of that working satisfactorily for long term mass data. Yet another task / windmill for our technological Don Quixote to tilt into! Archival grade DVDs seem to have a 50 year 'sure life'. Magnetic media (thinking tapes, 5 years, and reel tapes need to be 'exercised' annually to extend their lives). 'Flash' media like memory sticks need to be 'refreshed' by plugging in, even if data is not accessed, every year or two before bit rot starts. All these are 'rules of thumb', and detailed or specific cases can and will be quoted all over the place. When I worked for 'big oil' they had 50 years of mag tapes (from the oil field seismic data) that was stored well (exercised, in proper thermal environment, out of the weather, inside dust cases, etc), but they found a 50% failure rate on data 5 years old and older. They started just trashing their oldest seismic data. Re-digitizing what they could (in some cases paper maps and logs were better than digital data). This also made the data they had more useful. But even that had its failings. Old data was not of high enough resolution, or not measured in the spectra near what is currently used. So much old seismic data was kept, but new was acquired (at high cost in many cases) if possible to allow it to be useful in current exploration / re-exploration of potential fields. Oil companies only wildcat in the history books or in the movies. But this is only due to better data and being able to 'see' further below ground with better 'images' than they had in the past. Still, companies that bring in 1 good well for every 8 drilled in non-in-field-drilling is considered a great (world class) for 'wildcatting' (a term still used). But 14 dry to 1 good is very poor. And every well, wet or dry costs about the same (think 20 to 40 million on land and 4x or more that off shore even in relatively shallow waters). ... All that to say that good data, and properly archived data is STILL important to oil companies. And like it or not, our economy, but national and personal, even though most of us would rather be non-oil powered in our lives if possible. But currently, even off-gridders depend on oil based transport to bring good or take their goods to market, insulation on wires, and even making their solar modules available. The rest of us are more tied to it than they are. Oh well. Back to trying to keep ALL our data from having bit rot no matter why we need or want it safe. On Fri, Dec 5, 2014 at 10:20 AM, Allan West <al...@cookie.org> wrote: > On 2014/12/04 21:28, Edward Ned Harvey (lopser) wrote: > >> From: berg...@merctech.com [mailto:berg...@merctech.com] > >> > >> My biggest concern about the longevity of disk drives for off-line > storage > >> would be mechanical. A disk drive has a fair number of moving parts, > >> which have been designed to move, not sit still for extremely long > >> periods. Many years ago, disk drives were well known for having problems > >> spinning up if they were shut down for too long -- typically the problem > >> was ascribed to stuck bearings, congealed grease, etc > > > > One of my cousins is a very well educated librarian. She told me, > > decades ago they converted all the old centuries-old fragile paper > > books to microfiche, which has all now deteriorated, and the > > centuries-old paper books remain unchanged. She was asking me about > > data longevity on digital media, which they're currently in process > > scanning onto. My answer reaffirmed her suspicion that the new > > digital media is probably less reliable than the original paper, but > > at least the digital media has the option of being actively upkept, > > and will survive as long as you do regular upkeep diligence and > > maintain redundancy. > > > > So print the entire contents of every backup on paper and store the > > paper offsite in a waterproof, fireproof box. ;-) > > Serious electronic archives run fixity checks and migrate their data to > new media with some frequency. They also consume media like I consume > chocolate. > > If you want to know all about media longevity, chat with an electronic > archivist some time. Bring a pot of coffee and some snacks. Start near a > clean white board with multicolored dry erase pens. > > At $JOB(N-1), I was sysadmin for both active and "dark" archives, and I > learned not to idly bring up longevity issues. The gold standard for > longevity may be stone, but the data density sucks. That's why we use > "ephemeral" technologies like disk and tape. >8^) > Allan > _______________________________________________ > Tech mailing list > Tech@lists.lopsa.org > https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech > This list provided by the League of Professional System Administrators > http://lopsa.org/ > -- ><> ... Jack "Whatever you do, work at it with all your heart"... Colossians 3:23 "Anyone who has never made a mistake, has never tried anything new." - Albert Einstein "You don't manage people; you manage things. You lead people." - Admiral Grace Hopper, USN "Tell me and I forget. Teach me and I remember. Involve me and I learn." - Ben Franklin
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