Russell Coker wrote:
On Tue, 1 Jul 2014 10:03:44 Rohan McLeod wrote:
Noah O'Donoghue wrote:
Hi All,
After reading about bitrot and feeling guilty for storing my most valuable data on cheap drives (although with backups!) I've been thinking about moving to something more resilient. snip informative; but apart from a suggestion that it might be related to 'cosmic rays' and thermal magnetic effects; couldn't seem to find (a) a definition which is a measure of bitrot and (b) actual measures of this phenomenon in various media and differing conditions.
Presumably as a probabilistic phenomenon; bitrot might be defined in terms of the half-life of the data ? http://research.cs.wisc.edu/adsl/Publications/corruption-fast08.html
The above paper is the best reference I've seen. Half-life isn't a good measure as you can expect to lose ~50 sectors at a time on a TB+ disk. Thanks for responding Russell This paper doesn't seem to distinguish between corruption attributable to drive 'malfunction' and corruption which would have happened anyway ? eg while the drive was switched off But I notice : "/(ii) checksum mismatches within the same disk are not independent events and they show high spatial and temporal locality,"/ Presumably bitrot due to temperature would not show " high spatial locality " ? https://en.wikipedia.org/wiki/Curie_temperature ; so perhaps we can deduce cosmic rays a more likely cause, than temperature ?
regards Rohan McLeod