archiving data, was RE: Media Longitevity/Care

On Wed, 16 Mar 2005, Dwight K. Elvey wrote: I'd like to offer that there is no such thing as archival computer media. None. Dwight's comment is succinct; all offline storage needs to be checked. Literally all of it is rotting on the shelf. (For short-term backup, eg. data loss prevention, this logic doesn't apply so directly.) It's a lot of work to check archival data; nearly no one does it right, and it mostly amounts to spot checks (a valid method certainly but in itself an admission of the scope of the problem). I don't do "backups" per se; I keep everything on rotating spindles, aka hard disks in running systems. If you pause to consider what this means as a long-term solution, it sounds really precarious, because it is; but in fact it's *less precarious* than any form of offline storage because it is essentially 100% continuously monitored, embedded in a live computer. I have five computers in four physically distinct locations (three are >> 100 miles apart) with enough storage to hold literally all the computer-readable data I own. If you somehow think that tapes stored in a controlled vault is more reliable, or less susceptible to bit rot than rotating spindles, I believe you are wrong (and my every experience and observation says otherwise). Only fiche and paper are statically reliable. It's no crazier to think that my data (sic) will reside on a series of continuously operating computers for the next N decades than it is that a CD-R or DVD-R will last as long, or be readable N decades in the future. Yes, in one sense it makes me nervous. That's good! Dump tapes sitting in a closet or bank vault are rotting and becoming spectacularly incompatible; it just doesn't generally make people nervouse, but it should. Hard disk storage also neatly avoids the incompatible-media issue; it's continuously ported, incrementally. The translation issues are from M to M+1, far less than trying to deal with 8" floppies, 1/2" tape or other once-standard media. Also, for the moment at least, disks of tomorrow are chealer and larger than disks of today, neatly taking care of increasing data size (for how long this will hold out I don't know). Whether you have 10MB or 1 TB of data, it's still cheaper with rotating spindles. If you've really got a terabyte of data to reliably save, backup tape isn't cheaper -- if you include the longevity issue, of translating last-years tapes to next-years tape. Who does that? Not many... It's not about the medium, it's about the data. All of our mediums suck for archival purposes, except paper and fiche. Generally-speaking, our cultures don't directly care about preserving the future, and machine media is a narrower case of that.