Thumbs Up For Disk Warrior
I recently had an older Macbook Air drop dead due to a drive failure. On startup, the spinning wheel would just go forever and get nowhere. I was able to boot from a Lion USB image, but Disk Utility was unable to mount the main drive. From terminal, I was able to see that the partition table was screwed up. I set out to fix it by using a variety of bootable USB images including Linux Rescue Remix, Ubuntu, etc. I even tried messing around with rEFIt to see if I could somehow dual boot and then fix the OS X side from the linux side. Nothing worked.
At this point, I decided to remove the hard drive and try to restore it from another machine. The problem here is that the Macbook Air uses a special SATA connector. So upon removing the drive, I ordered a SATA LIF to standard SATA converter. I then mounted the drive into a SATA to USB enclosure and was able to power it up and see the disk from my Macbook Pro. From here, the only thing that was able to actually get data off the disk was “ddrescue”. Now, even though ddrescure was able to pull the data off, what I got at the end of the day was a million folders and a million files in absolutely no order what so ever. Not ideal, since sorting through everything was a horrible prospect.
Enter Disk Warrior (www.alsoft.com/diskwarrior). I read a variety of forums that gave me mixed reviews. People were claiming that it wasn’t worth the money, and that anything it did could be easily replicated from a terminal by anybody willing to put in a little work. For the price, I said “what the heck, let’s see what it can do.” And what it did was nothing short of amazing. It detected the broken drive that was plugged in via USB and gave me an option to “Rebuild it”. I thought “OK, there is no way this is going to do anything, especially after all of the things I’ve already done to the MBR, EFI partitions, etc.” Literally only a few minutes later, Disk Warrior comes back and says that the drive is damaged but it was able to recover most of the data and directory structure. It then mounts a “preview” drive for you which shows the broken drive as though it was healthy. EVERYTHING WAS THERE! And in it’s correct location!
Now, the next part is what truly made an enormous difference. Disk Warrior would let me pull the data off the broken drive and put it on another drive. But this is makes life a bit tricky since the OS X Migration assistant doesn’t play nice with arbitrary backups. So, I put a brand new SSD into the defunct MacBook Air. I installed a fresh copy of Mountain Lion from a USB image. I then installed Disk Warrior onto this fresh machine, and “rebuilt” the broken drive via USB. With the preview disk mounted, I ran Migration Assistant. Usually, you are required to quit ALL programs when running this assistant, and in fact it will do it automatically for you. Interestingly, Disk Warrior somehow bypasses this and continues to run in the background. So the preview disk stays mounted, and you can then just tell Migration Assistant to “transfer my data from a backup disk”. It recognizes the mounted preview as a valid OS X drive, and half an hour later, the system is completely restored.
So in conclusion, while one can do some tedious data recovery for free via ddrescue, I would recommend just paying for Disk Warrior and save yourself countless hours. The end result for me was a fully recovered system with zero data loss and every setting, customization, file, folder, etc. right where I left it. More importantly, back your computer up with Time Machine often! This is a lesson I’d rather not learn again.