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.
Out of curiosity I googled "bitrot" and whilst there seems to be some usage of "bitrot" in relation to RAM; mostly it seems to be in the context of storage media. As a novice I found:
http://arstechnica.com/information-technology/2014/01/bitrot-and-atomic-cows -inside-next-gen-filesystems/
http://en.wikipedia.org/wiki/Write_Anywhere_File_Layout That article claims that ZFS is the oldest of the "next generation filesystems". WAFL did it first and NetApp (the developer of WAFL) sued Sun alleging patent violation in ZFS.
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. On Tue, 1 Jul 2014 12:29:39 Peter Ross wrote:
For Russell: Have you seen this?
The first TODO entry is about file(1) and magic.
That is about ZFS dump files (the output of "zfs send") not the block devices. As I have never run zfs send and don't have any immediate plans to do so this hasn't been a concern for me. Thanks for the suggestion though, I've attached it to the Debian bug report. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/