Oh Mama! Another Backup Bouncer post! You might think that I, the author of Backup Bouncer, the crusader for end-user verification of backup tools, would have run BB on Time Machine at some point. If so, you have seriously underestimated my laziness. But this morning I got an e-mail from a user asking for help testing TM with BB, and this finally spurred me to do the test myself.

Here’s how you test Time Machine with Backup Bouncer:

$ mkdir ~/bb
# We need to trick BB into thinking this is a volume it created
$ touch ~/bb/bbouncer-vol
$ sudo bbouncer create ~/bb
# Now do a Time Machine backup and wait till it's done
$ mv ~/bb ~/bb-orig
# Now restore the ~/bb directory from Time Machine.  
# Try not to catch SPACE MADNESS!!!
$ bbouncer verify -d ~/bb-orig ~/bb

On my Leopard 10.5.3 machine here’s what I get with BB 0.1.3:

Verifying:    basic-permissions ... ok (Critical)
Verifying:           timestamps ... ok (Critical)
Verifying:             symlinks ... ok (Critical)
Verifying:    symlink-ownership ... FAIL 
Verifying:            hardlinks ... FAIL (Important)
Verifying:       resource-forks ... 
   Sub-test:             on files ... ok (Critical)
   Sub-test:  on hardlinked files ... FAIL (Important)
Verifying:         finder-flags ... ok (Critical)
Verifying:         finder-locks ... ok 
Verifying:        creation-date ... ok 
Verifying:            bsd-flags ... FAIL 
Verifying:       extended-attrs ... 
   Sub-test:             on files ... ok (Important)
   Sub-test:       on directories ... ok (Important)
   Sub-test:          on symlinks ... ok 
Verifying: access-control-lists ... 
   Sub-test:             on files ... ok (Important)
   Sub-test:              on dirs ... ok (Important)
Verifying:                 fifo ... FAIL 
Verifying:              devices ... FAIL 
Verifying:          combo-tests ... 
   Sub-test:  xattrs + rsrc forks ... ok 
   Sub-test:     lots of metadata ... ok 

The only annoyance is that hardlinks aren’t preserved, but that’s not surprising considering the way hardlinks are used internally by TM to prevent wasted space. (I should point out that the hardlink failure here is not the same as the Apple rsync one I mentioned earlier today, and it’s not nearly as bad.) These results are not perfect but I would have no problem recommending TM backups to any less-than-hardcore user.