Holy Crap, Apple Backup is Dangerous

So, I can think of a few things that need to be more reliable than my backup software:

1. Avionics.
2. Motorcycle gear.
3. Indoor plumbing.

So, for some months now (maybe more than a year?), Apple Backup has been my backup software of choice. The easy scheduling, the easy setup of multiple “plans” (ie, my e-mail to .Mac daily) and the like — it all came together in a pretty seamless package. Except for, well, this Labor Day weekend, when I thought I’d be a big dork and try to triple-boot Tiger, Leopard, and Windows Vista RC1.

I made an incremental backup before I started the mess, so I figured I’d be pretty okay, and I had been making backups regularly to an external FireWire drive for a loooong time, and all my *really* important data (read: code) is backed up offsite in various repositories, so what the hell. (Tangent: God damn these Intel Macs. For a good five years I had not wasted a weekend dorking around with screwing over my main machine with various trendy operating systems because there was only one trendy operating system that ran on my PowerPC machines. Between you and me, I love operating systems. I mean, even the term “operating system” — is that cool, or what? You’re getting hella software with that, bro. FWIW, IMHO: trying to triple-boot anything involving a MS product on a MacBook Pro: waste of time.)

The funny thing about backup software is that its entire value is the amount of confidence it inspires in your ability to recover from failure quickly. For example, before I used Apple Backup I used rsync, and rsync inspired so much confidence that I’d happily ride a Vespa to work, laptop slung over the shoulder Euro style, without worrying about what would happen if I fell off and landed on the laptop. This actually happened and I bought a new hard drive (the only damaged part!), reinstalled, and rsync’d my data back, and was up and coding later that evening. At other times I’ve been able to restore from Apple Backup, though the reasons for doing so were not a result of spectacular Vespa crash.

But, point being, having backups inspires risk-taking. In the same way that wearing a full-face helmet inspires risk-taking. “I can totally squeeze between that crackhead taxi cab and that blind guy driving the SUV! I have a full-face!”… I mean, Windows Vista on Apple hardware? How could that go wrong? And what the fuck, I have backups!

So, Apple Backup failed me monstrously today. I have a measly 100G drive in the MBP, which means I have about 60G of home directory to restore, and Backup kept failing about 30G in. But, of course, it wouldn’t directly fail, it’d simply stop writing to the disk (as confirmed with iozone: the classics never die) and proceed to allocate 2GB of memory. You see, at 1500MB I kinda just hoped it was a spike. No dice. Anyway, if you are ever confronted with this, you can get your precious data out by:

1. In your backup folder, there will be a number of .sparseimage files. These hold your data.
2. Mount all of the .sparseimages in your backup set (that means the .FullBackup followed by the .IncrementalBackup)
3. Sort the mount points by age. Painful.
4. rsync the data out.

Anyhoo, my big complaints are that if there was a problem backing up, I never heard about it; the failure recovery case in Apple Backup is just awful (”keep allocating until it works!”), and the storage format is fairly convoluted (.backup files get points in my book for being the first to do a Contents/Contents/ path structure).

And the tool that saved my day? rsync. (Of course, ditto would have worked well too). I am moving back to rsync until Time Machine ships. But, hey, wait: Time Machine, at least as I’ve experienced it, isn’t really an archival-style backup solution, it’s a “restore that file from last week Tuesday” kind of solution. Hmm.