Good point... Craig - would it make sense to add a parameter to BackupPC_nightly that would check a user-settable percentage of the files each night, say NightlyChecksumPercent. So if set to 3%, the pool would be checked (sequentially) over the period of ~1 month
Guillermo Rozas wrote at about 11:12:39 -0300 on Monday, June 8, 2020: > Yes, I wouldn't worry about collisions by chance. > > However, there is a second aspect that is not covered here: if you > rely only on saved checksums in the server, it will not check again > unmodified pool files. This risks you missing file system corruption > or bit rot in the backup files that were previously caught by the V3 > behaviour (which periodically checksummed the pool files). > > Two solutions: > - put the pool in a file system with checksum verification included > - use a script to periodically traverse the pool and chesum the files > > Best regards, > Guillermo > > > > On Mon, Jun 8, 2020 at 10:58 AM G.W. Haywood via BackupPC-users > <backuppc-users@lists.sourceforge.net> wrote: > > > > Hi there, > > > > On Mon, 8 Jun 2020, Jeff Kosowsky wrote: > > > > > ... presumably a very rare event ... > > > > That's putting it a little mildly. > > > > If it's really all truly random, then if you tried random collisions a > > million times per picosecond you would (probably) need of the order of > > ten trillion years to have a good chance of finding one... > > > > $ echo ' scale=2; 2^128 / 10^6 / 10^12 / 86400 / 365 / 10^12 ' | bc > > 10.79 > > > > I think it's safe to say that it's not going to happen by chance. > > > > If it's truly random. > > > > -- > > > > 73, > > Ged. > > > > > > _______________________________________________ > > BackupPC-users mailing list > > BackupPC-users@lists.sourceforge.net > > List: https://lists.sourceforge.net/lists/listinfo/backuppc-users > > Wiki: http://backuppc.wiki.sourceforge.net > > Project: http://backuppc.sourceforge.net/ > > > _______________________________________________ > BackupPC-users mailing list > BackupPC-users@lists.sourceforge.net > List: https://lists.sourceforge.net/lists/listinfo/backuppc-users > Wiki: http://backuppc.wiki.sourceforge.net > Project: http://backuppc.sourceforge.net/ _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
