On 2014-12-04, at 11:47 AM, Arno Hautala <[email protected]> wrote: > The tl;dr for this that tmutil might provide some of what you're > looking for, but if you don't trust TimeMachine, you should use a > different backup tool.
It isn't about whether or not I trust Time Machine, or a different tool. 1. No backup tool will protect against a drive error that stores the wrong thing onto the disk. At best, you can flush the system cache, and re-read the file. That only guarantees that it matches today. 2. No tool can be considered perfect against bugs. They can and will happen. I found, and reported, an issue with Time Machine. Does not mean that other tools don't have other problems. > On Thu, Dec 4, 2014 at 12:25 PM, Michael <[email protected]> wrote: >> >> What I envision: >> 1. A tool to list "which files on the backup do not need to be backed up" -- >> in other words, the list of files that time machine think are worth backing >> up but can be skipped. These can then be sent to a diff-tool to verify that >> what is on the backup matches. > > TimeMachine determines what needs to be backed up by watching FSEvents > for directories with changed files. During the backup TM then inspects > every file inside the flagged directories. > To build your list of files to check, you'd need to do the same thing. No, that doesn't work, and tells me that I wasn't clear. So let me try again. FSEvents tells backupd which directories have modified files; backupd checks each of those directories to see which files have been changed. It then consults an internal list of "do not back up", the system list of user-specified "do not back up" files, and the per-file "do not back up" meta data flag. If all of those pass, then it decides to back it up. I want a list of all the files on the machine that would be backed up if it were doing a "from-scratch" backup, EXCEPT for those where FSEvents says "This needs to be backed up". That is the list of everything on the backup that should match the file system. >> 2. A way to let time machine know that "Hey, this file does not actually >> match, and needs to be backed up". "Delete all backups of file X" is one >> such, but it is overkill. On the other hand, if the file on the backup is in >> error, maybe it should be removed. It is also not quite sufficient, if files >> should be backed up but are missing. > > I don't think there's any method to do this other than modifying the > target files so TimeMachine explicitly notices the file. Yea, I want to force TM to re-backup, without having to change the file. Not even change the date. Basically, a way to tell time machine "the existing file on the backup properly belongs to an older backup set, but should be replaced anew on the next backup set." > You can use the tmutil command to see what differs in any two > snapshots or from a snapshot to the current computer state. True. Now, do you have a way to say "Only tell me if backupd would not want to back this up"? If it's different, but backupd would back it up, then I don't care. Or if backupd would say "This is on the do not backup list", then I don't care. _______________________________________________ MacOSX-talk mailing list [email protected] http://www.omnigroup.com/mailman/listinfo/macosx-talk
