Monday, February 12, 2007

Just barely better than no backup at all...

So, the hard drive on my Mac died. Disk Utility won't fix it, Techtool pro just throws up its hands at the 2,000 bad blocks on the drive, etc, etc.

That kind of sucks, but at least I have relatively recent backups to restore from. Or, maybe I actually don't. I've been using the .Mac Backup program to do backups for the last year or so - prior to that, I was just bulk-copying stuff by hand to an external hard drive. The Backup program is a lot more convenient, and makes much better use of the space on the external drive.

I figured that surely, now that Backup is at version 3.1, it'll be rock-solid reliable, right? I mean, once they fixed that awful crashing bug I reported back in the 1.0 days, I hadn't noticed any problems, so everything is OK, right? Well, as it turns out, Backup 3.1 is no more reliable than the old Backup - it just has different bugs. Now, instead of crashing on backing up large numbers of files, it crashes when trying to restore them. If I was given a choice between these two behaviors, which do you think I would have chosen?

The one saving grace is that inside the broken Backup file package is a more-or-less standard Mac OS X disk image file. So, I can mount those files (one from the last full backup, and one from each of the incrementals), and hand-copy the files over from them. Let's hear it for unreliable backup software...

5 comments:

Joe said...

Maybe you should try using Super Duper.

Mark Bessey said...

I'll definitely check out some of the alternatives, but I think I'm heading back to my old way of thinking on this subject. Any backup system where I'm dependent on some third party software to get my files back isn't worth the risk.

Subrata Sircar said...

To be fair, it seems possible that the same thing that caused your hard drive failure could have corrupted the files that Backup is trying to unpack.

At any rate, if your external drive is the same size as the primary, you could just try rsync (or even spiffier, build your own tar-gzip archive and rsync that). That doesn't count as 3rd-party software, right?

Mark Bessey said...

Subrata,

I don't think that the two incidents are related, because the Backup files were stored on an external disk that wasn't even plugged in when the main disk crashed. Given that the error I get in the backup log indicates a CoreFoundation assert violation, I suspect it's just bad code in Backup.

I'll probably try scheduling a periodic rsync to an external disk as my new backup "system". I'm tempted to try to build something more sophisticated out of simple building blocks, but I fear that I'd spend a lot of time to get something not substantially better.

Subrata Sircar said...

I rely on rsync to keep all the music/pictures/etc. information in sync on four machines, and it works pretty well for that. (It's not a true backup, since I actually use the data on multiple hosts, although only one at a time, but it protects me against accidents if I catch things in time, and it definitely protects me against hard-disk failures and the like.)

If you wanted a true backup, with efficient space usage, you could prepare a giant tar/gzip archive and use rsync to push just the diffs over each time.