On 2014-12-05, at 10:50 PM, Macs R We <[email protected]> wrote: > > On Dec 5, 2014, at 9:07 PM, Arno Hautala <[email protected]> wrote: > >> So, you want a list of files that have already been backed up, that >> haven't changed on the filesystem, so you can verify that the data has >> been correctly backed up. In the ideal case, if performed immediately >> after the backup completes, this would be every file in the backup. >> >> I think the easiest way to do this would be to just compare the backup >> to the current state (tmutil compare). If the list of differing files >> is the same as the list of files that need to be backed up (collected >> by fsevents), your backup can be considered verified. > > Well, that just verifies the table of contents. I think he wants to verify > the contents (data), and for that he needs the table of contents as a first > step.
Correct. ZFS's checksums can tell me "Hey, the data you tried to read is no good". I want to know that before I need to restore from backup. I can't use ZFS for time machine. I can't control whether the drive's internal buffer is error correcting memory or not. I can't control if the disk sector was written correctly but has become unreadable. All I can do is compare what's on the disk with what's on the backup, file by file. "tmutil compare" can do that, but it will report too many false positives -- everything modified since the last backup will show as different, and everything that should not be backed up will show as missing. To have an automated verification, I need to be able to filter to only those files that should be on the backup and have not changed / do not need to be backed up again. === Open Radar: I'm not sure. About half of what I submit is closed as a duplicate, and I can never see the originals. I have no clue how to see someone else's bug report, nor how to share mine. _______________________________________________ MacOSX-talk mailing list [email protected] http://www.omnigroup.com/mailman/listinfo/macosx-talk
