Re: Verifying file data integrity using L6

[cjs () CYNIC NET (Curt Sampson)]

On Sun, 20 Dec 1998, Marc SCHAEFER wrote:

> In article <75jlfu$lk3$1 () vulcan alphanet ch> you wrote:
> > This seems to be something that a good backup/archive system[1] ought
> > to be recording whilst it backs up files, so that one could simply run
> > a check of all files on a system against those in the database.
>
> tar has a compare option, comparing filestamps, size and md5.
> rpm has a verify option
> cpio has a CRC option.
> tar can be used with Amanda backup.

All of these store the checksum or CRC with the data, which I don't
think this fellow was looking for.

Many backup systems keep an on-line database of all of the files
that have been backed up, so you can find out when a file last
changed, what tapes it is on, and so on. If this database also
stored the CRCs of all the versions of the files, you could check
the integrety of the file against this database, rather than against
the backup.

cjs
--
Curt Sampson  <cjs () cynic net>   604 801 5335   De gustibus, aut bene aut nihil.
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