Merry Crashmas

My hard drive that houses my music collection went crazy this morning. I opened Disk Utility to let it work its magic. After running “verify” It reported the following:

Verifying volume “lacie”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Keys out of order
The volume lacie needs to be repaired.

Error: The underlying task reported failure on exit
1 HFS volume checked
Volume needs repair

I clicked on “repair” and waited for the good doctor to make my troubles go away. It looks like the patient might be terminal.

Verify and Repair disk “lacie”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Invalid key length
Volume check failed.

Error: The underlying task reported failure on exit

1 HFS volume checked
1 volume could not be repaired because of an error

After fretting about losing all that music that I bought on the iTunes Music Store and the idea of having to rip all my CDs again I decided it was time for some UNIX magic. Enter “dd.”

“dd” is a disk copying utility that allows you to copy, bit for bit, the contents of a disk or file. By telling the program to not report errors on bad blocks it will just plow its way over the errors. The error areas will have null bits inserted into them to act as filler for the messed up blocks. This allows me to at least look at the file and determine how screwed up it is rather than simply trashing it. The command that I ran is:

dd bs=512 if=/dev/rdisk2s6 of=/Volumes/Purgatory/foo.dmg conv=noerror,sync

The souce disk (/dev/rdisk2s6) is copying to my external Firewire drive (Purgatory) at a crawling pace. At the rate that it is going it will take at least 72 hours total. It is also reporting some interesting stuff in the terminal. Of course I have no idea what this means, but it’s saying it pretty often.

114300577+0 records in
114300577+0 records out
58521895424 bytes transferred in 59426.141337 secs (984784 bytes/sec)
dd: /dev/rdisk2s6: Input/output error


I’ll report back once it is actually done. Hopefully the image will actually open and I can recover some of this stuff. We’ll see.