Need Help With B-tree problem

If you data is in fact priceless like you say you should have no problem sending it to a data recovery center that can properly recovery the data. Instead you would rather risk damaging it even further and potentially causing the data to be unrecoverable by doing it yourself. Not the smartest thing to do with priceless data.

 

You didn't mention what behavior you're seeing. I assume this is the boot disk. Does the machine boot? If not my suggestion is this:

1) Buy another internal drive and swap it in for the problem drive. While you're buying drives you may actually want to buy two. It will make recovering your data easier and you'll have a spare for backups in the future.
2) Install an OS on it
3) Find a way to mount the former internal drive externally. One of the easiest ways is to buy a Seagate GoFlex USB adapter for $20. The bare drive will plug right onto it. If you bought that second internal drive, get two of these.
4) Download Carbon Copy Cloner from bombich.com This used to be shareware and there still may be a shareware version available. Otherwise it's $30 which is cheap for what it does. Try cloning your problem drive to the extra new one with CCC. You may be able to recover most of your files this way. How many will depend on where the corrupt nodes in the tree are and whether the problem is in the catalog btree or the extents btree.
5) If that doesn't work, there's an excellent recovery tool available from Prosoft Engineering called Data Rescue 3. We're starting to get into more serious money here ($99) but the software can recover data from some seriously hosed disks. I've used it myself to recover critical files for clients... and for a girlfriend. In her case the $99 was far less than the pair of shoes I would have had to buy her to console her for losing her precious pics.

Prosoft also has a very good utility called Drive Genius 3 (also $99) which, among other things, does a pretty fair job of rebuilding damaged directories. I'd use that as a last resort. You really want to write NOTHING to the problem disk until you've recovered your data. Trying to repair the directory does run the risk of making everything unrecoverable. I can't stress this enough. Make sure you do nothing that can write data to the problem disk until either the data is recovered or you're out of options. If it boots now, stop booting from it. Swap in a new drive and then get the data off of the problem one.

As for using a data recovery service... that will be pricey. I once spent nearly $4000 to have critical data recovered from a client disk with a head crash. You can be sure the client put a serious backup system in place after that.

A recovery service will do the above steps first in any case. They also usually have the advantage of having a clean room and equipment in place to allow them to get data off of physically damaged disks. If the disk physically spins up and the problem is just corruption in the catalog or extents tables, then Data Rescue 3 will probably be able to get it back.

Be prepared for some work no matter who does the data recovery. Depending on the extent of the problem, you may not get the original file names back. The software will scan the disk looking for files. In that case your recovered data will be grouped by file type and you'll have to examine the to see what's what.

But hey... All of this assumes your computer isn't booting. First tell us what the drive is doing.

 

Having dealt with many, many, many of these kinds of drive failures, ]I can give you a few bits of advice:

- First, be prepared to deal with the fact that you may have lost most if not all of your data, depending on how bad the problem is.

- Do not attempt to use the computer for any reason, don't even try starting it up. Doing so with further exacerbate the problem. Something like Disk Warrior may be able to fix the problem so that you can transfer your data over if it is in fact, not a hardware problem.

- Definitely explore data recovery options like Drive Savers if it turns out to be a hardware problem. It will be expensive. But that's the price you pay for not having a proper backup solution.

Mac OS X comes with Time Machine. All you need to do is spend $50-100 on a decent sized external hard drive and your data is safe. There's really not any excuse for this in today's world, especially if your drive holds priceless data. Any drive in any computer can fail at any time for any reason. Remember that.