Just a thought here, I don't know about you, but over my career I have never had to go into such archives even though they are frequently made. In fact, what I have found in too many cases is that the division or company making these type of archival backups do not survive the media lifetime and thus would be no longer needed.
+++++++++++++++++++++++++++++++++ Michael D. Parker -----Original Message----- From: tech-boun...@lists.lopsa.org [mailto:tech-boun...@lists.lopsa.org] On Behalf Of Charles Polisher Sent: Saturday, December 06, 2014 12:23 PM To: Bill Bogstad Cc: tech@lists.lopsa.org Subject: Re: [lopsa-tech] Data on longevity of powered off disk drives? Bill Bogstad wrote: > Edward Ned Harvey (lopser) > recovery industry would be of interest. For example, I don't have > the physic background to even intelligently guess if individual > magnetic regions/domains on a drive platter will degrade their > neighbors over time, but someone else might. Admittedly, this is only > one part of whether an entire drive will remain readable; but it might > put a useful ceiling on the maximum longevity of an unpowered drive. I worked in an engineering setting designing and calculating the reliability of analog and didtal circuits. I'd expect a disk drive's electronic components to last about 20 years unpowered. The least likely to survive long-term are electrolytic capac- itors which have a paste electrolyte that can dry out, and EEPROMs (if they're used, I have some drives that do) will hold their charge for about 20 years I've been told. I've a hunch the platters themselves are quite stable, but here AF (advanced format) drives have a huge advantage because they're better able to survive thermal asperities caused when stray particles squeeze between the head and platter causing local heating and subsequent data loss. AF drives have more built-in error correction increasing the chances of readable data. LTO-5 tape systems are designed for 30-year archival use and for my use case a better bet. I expect compatible (LTO-5) drives to still be marketed over the next 30 years - well past my own personal expiration date. -- Charles _______________________________________________ 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/ _______________________________________________ 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/
