HD crash beyond repair (b-tree catalog damaged)

Hello,

I've got a nasty problem... After upgrading from 10.3.9 to 10.4 all went well for 15 minutes, then the system froze and after a hard reboot the I had the infamous blinking question mark.
Booting from DVD or firewire disk failed to mount the hard disk.

Disk first aid from the installer and from a firewire disk couldn't verify nor repair the disk (terminating on "invalid b-tree node size" and "underlying task reported failure on exit"). Other disk repair apps didn't even see the disk. Via Terminal i can detect but not access the disk.

Anyone has any idea how to salvage data from that disk (yes, I know, I should have made a backup... this was actually the first time in years of upgrades without a problem I thought: what the... let's do this quickly before going to sleep, let's skip the backup. I hate Murphy!)

You might be able to retrieve some of your files if you booted your Mac from an external disk (that has OS X installed on it). Alternatively, you could mount your Mac's disk on another Mac using "target disk mode": http://docs.info.apple.com/article.html?artnum=58583

You also might recover some of the files by using a 3rd-party utility like "Data Rescue" or "FileSalvage" or "Virtual Lab" or the command-line utility 'dd_rescue' (google to find them).

DiskWarrior just might be able to salvage even a disk with this sort of damage. If you haven't tried it, you should. It is a tool that is worth every penny you pay for it.

It is important to be able to boot from the Disk Warrior disk in this case, and in the case of severe damage, it might take Disk Warrior a very long time to work. There is no guarantee there won't be data loss, or that Disk Warrior can repair the damage, but if any product is likely to be able to, it is this one and most here (I think) would agree that it's a tool every Mac user should have.

Joe VanZandt