TimeMachine failing to realise a mounted network share contains an existing TimeMachine backup
Right, so the worse has happened… your shiny Mac has gone wrong – while booting it took forever and showed a mysterious grey/white progress bar. A progress bar you’ve never seen before. The machine eventually boots and on your boot drive a curious new folder has appeared with the ominous name of damaged files. Not to worry though, you were one of those smug happy people with a TimeMachine backup that goes to
The 'Damaged Files' folder on a Mac partition. If you see this, something bad has happened.
a different machine using Netatalk and that little hack for remote drives. Fantastic… you’ve six months of backups and all is well. So when you boot your Mac and discover this horrifying little mess which means your Mac ran its equivalent of fsck and it found problems you can fix it.
In the world of attached USB TimeMachine drives, you just enter TimeMachine and recover the bad data – or totally reinstall and use the ‘Restore from TimeMachine’ option which is rather pain free. Really, it’s so simple to make TimeMachine operate with a USB drive you are a complete moron if you aren’t using it. Apple have made backups so hassle free, and USB drives are so cheap there’s no excuse.
Sometimes though, those network TimeMachine drives just won’t behave – suppose you bought a new server where the TimeMachine backup lives, and it has a new network name… The Mac won’t see the backup as being there, it’ll want to make a new one (I think the server name gets added to the TimeMachine backup’s identity). Occasionally if things are going really badly your Mac won’t even recognise the network share as being somewhere that even has a TimeMachine backup on it. This is the time to begin cautious panic – you have backups full of live healthy data but you can’t get to them; it’s like starving to death in a Heinz beans factory because you have no tin opener.
Fortunately you can still get the data off it:
- Mount the shared network volume that has your TimeMachine sparsebundle on – you need to be able to see the actual Sparsebundle file in a Finder window (so copying it manually onto a different drive and plugging that in your Mac will probably work too if stuff has gone really really wrong)
- Type the following
hdid /Volumes/james\ TimeMachine-2/_34159e23d2e2.sparsebundle
and replace the stuff after ‘hdid’ with the full path to your sparsebundle – you can just drag the icon out of Finder and drop it onto the Terminal window. You’ll then see something like this:
/dev/disk3 GUID_partition_scheme /dev/disk3s1 EFI /dev/disk3s2 Apple_HFS /Volumes/Time Machine
Which means it found a valid partition in there and has mounted it on your desktop. Navigate the rather pleasing folder structure and feel happy that – while not supported – network TimeMachine backups do work in a sane way at a low level using the regular disk management tools on your Mac. It’s not data hidden away inside some special backup tool.
Then go fix your Mac, it’s got issues – random applications will now be corrupt.
