Hello, Virtually all backup programs base the decision to backup a file or not on the time stamp. Some programs, including Bacula, do have other means of finding if a new file has been added into the backup tree with a old date, or that files have been removed from the backup tree. This functionality is available within the Bacula FD, but I am not sure of the details of all the details for dealing with it in a plugin, though I know that is possible.
That said, unless you can find another developer, most of us are very busy (too busy), and before we spend any time answering your questions, I have several for you: 1. From the larger picture, what is the purpose of your plugin. 2. Will the resulting code be licensed with the GPL? 3. Will you make the code available to the Bacula project? Best regards, Kern On Friday 22 October 2010 21:15:50 Andrew Deason wrote: > Hello, > > I've recently been looking at developing a bacula FD plugin for > something, but I'm a little confused as to how incremental/differential > backups are expected to be implemented. > > >From what I can tell, FD plugins are just given the timestamp of the > > last backup run we want to get changes from. (either obtained from > getBaculaValue for bVarSinceTime, or from the bEventSince event in > handlePluginEvent) If I determine what data to backup just based on that > time, though, it seems unsafe, if a file has e.g. a mod time before that > date, but was not backed up successfully in that backup job. I could be > completely wrong on that, but, well, for example: > > Say we do a full backup at time T1, and an incremental at time T2 > T1. > For the incremental backup we're given a "since time" of T1. Now say we > have a file F, which has an mtime less than T1. When we did the full > backup of T1, say there was an error reading file F, or file F was not > in the backed-up directory tree at time T1, and was moved there between > T1 and T2. Now, at time T2 when we do the incremental, the backed-up > data does not contain file F at all, since its mtime is less than T1. > And if F never changes, it never gets backed up until the next full > backup. > > What I would have thought is that there would be some way to get some > information from bacula about the last successful backup, or something > about the successful backups for file F, or something along those lines. > But I don't see any such interfaces in the Bacula FD plugin interface. > > Am I, the plugin, expected to keep track of this internally? Or is the > scenario I describe just not really considered a problem? Or have I > screwed up the logic in this somehow, and it's not actually a problem? ------------------------------------------------------------------------------ Nokia and AT&T present the 2010 Calling All Innovators-North America contest Create new apps & games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev _______________________________________________ Bacula-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-devel
