Mac OSX hard disk gives invalid PEOF - how do I back up data?

Question

Yesterday my macbook pro (running 10.6.8) refused to reboot, and after booting it using the install disk and running disk utility I got Invalid catalog PEOF. The volume could not be verified completely. So, from the looks of it, I may have to reinstall the OS:

1. Is there anything else I can try?
2. If not, how can I access the disk and try and save some data before formatting (if at all)?

I'm not stranger to command line unix and all that if needs be. Any help will be great, thanks.

Answer 1

Do you have another Mac? If so you can connect the failed Mac to your other mac via firewire and you target disk mode.

Power off the failed mac, connect it to the working mac via firewire. (The working mac can already be powered on) Boot the failed mac and immediately hold down the T key on the failed mac. Continue holding it until the firewire icon shows up on screen. You should then see the mac mounted on the working mac.

Link with more details http://support.apple.com/kb/ht1661

Also an interesting link with some details on your error http://support.apple.com/kb/TA21624?viewlocale=en_US

Answer 2

If you don't have firewire as an option, here's how I recently recovered almost all my files using DiskWarrior:

1. Boot your machine from your install disk
2. Run Disk Utility
3. Create a new image of your corrupt disk on an external drive. To do this, connect your external drive then select the corrupted drive in Disk Utility and click on the "New Image" icon in the top menubar. Compressed is ok. This could take a lot of time and space depending on the size of your disk.
4. Plug the drive with the new image into another computer with DiskWarrior installed

5. I was not able to mount the image in Finder (double-clicking on the dmg file), so I went into the terminal and manually mounted the image. I used this call to ignore warnings and basically force it to mount:

   sudo hdiutil attach -noverify -mount suppressed /yourpath/yourimage.dmg

6. Launch DiskWarrior and choose the blank entry in the drop-down to rebuild the directory structure

Since DiskWarrior does not provide terminal access when booting from the DVD, there is no way I could find to directly force the mount on the existing machine, hence the extra step of copying the image out.