I spent a good portion of last week attempting to recover about 30GB of movies that had been deleted from a Mac with a 60GB hard disk. When a file is deleted its normally left intact on the hard disk except for a marker saying its space can be reused. This means that deleted files can be fairly reliably recovered, so long as the space hasn’t since been used for other purposes. We found the movies were missing only a few days after they were deleted, and they took up half the hard disk, so I was fairly confident they could be in part recovered.

Of course that’s great in theory but in practice how I was I going to recover those files? A quick bit of Googling discovered three programs that will attempt to recover deleted files on the Mac:Boomerang, FileSalvage, and Data Rescue II. I downloaded a trial copy of each and set to work. Here’s how they performed:

• Boomerang ran very quickly but only found some 29MB of the missing 30GB of movies. Of the three programs I tested it is the easiest to use, with only a few options for the most common problems. It also does a better job of sticking to the Mac interface conventions than the other two.
• FileSalvage took many hours to search the hard disk. It found lots of files, but it didn’t identify many as fragments of movies. Additionally the interface is very clunky. It doesn’t use the standard Mac widgets and selecting file types in Expert mode is a real pain.
• Data Rescue II ran fairly quickly and found almost all the lost data. Success! It is fairly easy to use. The guided standard mode does a good job of leading you through the recovery process, and the many options in Expert mode are explained well. Like the other programs it uses non-standard widgets, and this needlessly detracts from its usability.

So in my testing Data Rescue II was the clear winner. Don’t read too much into this, as I was only looking for movie data; one of the other programs might work better for a different type of file. However, if you’ve deleted some files that you want to recover I would start with Data Rescue II, then try Boomerang, and only then try FileSalvage (and go to bed while it’s running). Finally, if you have two Macs a firewire cable and target disk mode will make the whole recovery process a bit simpler.

Now what I want to know is: why would a Mac developer invent their own user interface widgets unless they really want that amateur feel to their product? Is there something about Cocoa programming that makes it easier to create, say, your own tab component than use the system one?