| 1 |
On Jan 8, 2013 11:20 PM, "Florian Philipp" <lists@×××××××××××.net> wrote: |
| 2 |
> |
| 3 |
|
| 4 |
-- snip -- |
| 5 |
|
| 6 |
> |
| 7 |
> Hmm, good idea, albeit similar to the `md5sum -c`. Either tool leaves |
| 8 |
> you with the problem of distinguishing between legitimate changes (i.e. |
| 9 |
> a user wrote to the file) and decay. |
| 10 |
> |
| 11 |
> When you have completely static content, md5sum, rsync and friends are |
| 12 |
> sufficient. But if you have content that changes from time to time, the |
| 13 |
> number of false-positives would be too high. In this case, I think you |
| 14 |
> could easily distinguish by comparing both file content and time stamps. |
| 15 |
> |
| 16 |
> Now, that of course introduces the problem that decay could occur in the |
| 17 |
> same time frame as a legitimate change, thus masking the decay. To |
| 18 |
> reduce this risk, you have to reduce the checking interval. |
| 19 |
> |
| 20 |
> Regards, |
| 21 |
> Florian Philipp |
| 22 |
> |
| 23 |
|
| 24 |
IMO, we're all barking up the wrong tree here... |
| 25 |
|
| 26 |
Before a file's content can change without user involvement, bit rot must |
| 27 |
first get through the checksum (CRC?) of the hard disk itself. There will |
| 28 |
be no 'gradual degradation of data', just 'catastrophic data loss'. |
| 29 |
|
| 30 |
I would rather focus my efforts on ensuring that my backups are always |
| 31 |
restorable, at least until the most recent time of archival. |
| 32 |
|
| 33 |
Rgds, |
| 34 |
-- |
Archives