mac os x external fire wire drive will not mount

futr_2o4t
futr_2o4t used Ask the Experts™
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My intel iMac locked up, and I had to do a hard reset.  iTunes was still playing music from the external firewire drive when I did the hard reset.  Upon power up, the drive would not mount.  It appears in System Profiler under Firewire as Journaled HFS+ drive with no mount point.  Thinking it might be a corrupt partition table, I ran Test Disk, then pdisk with the intention of rebuilding the partition table.  However, they seem to match.  Disk Utility sees the disk, but when I Verify Disk, it gives an error of "The underlying task reported failure on exit."  (See attached file.)  The Repair Disk button is selectable, but I am afraid to do anything that will write to the drive without fully understanding what condition the drive is in.

I have searched for 3 days now to find a similar scenario, but have not found one.  It seems like there is no hardware issue with the drive, and all the data appears to be intact.  I really don't want to lose the data on this drive.  Maybe I'm just so freaked about this that I'm not seeing the solution.  What should I do?
IomegaHDinfo.txt
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noxchoIT Product Manager
Top Expert 2009
Commented:
Try to boot from Mac installation disks and enter Disk Utility from there (do not run MacOS installation).
Check the drive via Disk Utility.
Also I think Repair Disk is your only option here and that should not loose you data.
No need to boot from the system disk. Just use Disk Utility while booted from the hard drive. Since you are not trying to repair your boot disk, you do not need to boot from the system CD.

Commented:
if you are having problems with disk utility you might want to try booting and repairing from another macintosh and change the disk name as yours may have a corrupt mount point retained for that disk when you experienced the crash.    Then when you mount again on your macintosh it will see it as a new disk and create a new mount point.
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Author

Commented:
Forgot to state that I did try to attach the drive to my iMac G4, but it also would not mount the drive.  It did see show it in System Profiler under Firewire, just like the intel iMac.

It sounds like the consensus is that it will be safe to run Repair Disk.  I will steel my nerves, attempt it this afternoon, and report back with results.

Author

Commented:
I tried Disk Utility Repair Disk.  Luckily, the worst did not happen, but unfortunately it would not repair the drive.  Here is the log:

--------------------------------------------------
Verify and Repair disk “Iomega HDD”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Invalid node structure
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
-------------------------------------------------

I don't have Disk Warrior. I have Tech Tool Plus v 3.0.4, but it does not see the volume.  What should I do next?
noxchoIT Product Manager
Top Expert 2009

Commented:
Did you test it from MacOS install disk?
If the data on the drive is important to you, your best bet to recover it is DataRescue III:  http://www.prosofteng.com/products/data_rescue.php

There is a free demo at the link above which will give you a list of recoverable files and allow you to recover one file for free. If you want to recover more, you have to pay for the software.

If you don't care about the contents of the drive, just reformat it.

Author

Commented:
I do not have the original install disks, due to a moment of well-intentioned generosity.  

I am going to try Data Rescue 3 and will post the results.

Commented:
Before you go the rescue route, did you try fsck from the command line on that disk?  Sometimes the old unix ways can fix disk issues like that.. ..esp. if it won't mount but the disk is visible to the underlying OS.

Author

Commented:
roylong - I hadn't tried fsck, but I'm not real comfortable at the command line level, so this is what I did.

fsck_hfs -q /dev/disk1s10
** /dev/rdisk1s10
QUICKCHECK ONLY; FILESYSTEM DIRTY

Not sure how to proceed, as this is a Journaled HFS+ drive, and I don't know enough about the command line options to be sure that I'm going to do it right.  
Commented:
If you run the same command as you already did (I presume that is against your external drive and not another disk?), with the following change:

fsck_hfs -y /dev/disk1s10

then this will attempt to fix any issues which are found - and continue through the entire disk fixing as it goes.  I use fsck to fix my drive issues on OS X and Linux all the time and it works like a charm most of the time.  I've had it quit without being able to fix, but never has it screwed anything up.


Here's some more information on fsck and fsck_hfs if you need it:
http://osxfaq.com/Tutorials/fsck/index.ws

Author

Commented:
I haven't abandoned this question, just haven't finished resolving the problem.  I will post results as soon as I'm done.  Thanks for the all the help so far; I will award points as soon as I'm done on my end.

Author

Commented:
The hard drive is fully repaired.  Using the fsck_hfs -y [disk] worked.  It took two attempts. The first attempt gave the volume repaired successfully message, but it still would not mount.  The second attempt gave the volume appears to be okay message, and then it mounted.

I confess that I found a cheap copy of Data Rescue 3 and recovered all the files before dabbling in unix :). I still did the fsck_hsf solution, so others can go forward in confidence if they run into the same problem.  I'm happy that it was the best solution and hope that it will save others some $$$.

I split the points based on the following:

1. I needed confidence to attempt to use the Drive Utility Repair option without feeling like I was going to damage the disk by writing to it.  @noxcho 's first comment got me through that point.

2. @strung left a good reminder that I didn't need to boot from an installation disk to fix an external drive problem.

3. I didn't know about Data Rescue 3, so @strung clued me in.  It may be obvious to everyone else, but I don't have time to keep up on things that aren't required for my everyday life.

4. @roylong knows his stuff!  This was the primary solution to this hard drive problem, but without his guidance I would not have been willing to work at the command line.

Thank-you for all your help!
noxchoIT Product Manager
Top Expert 2009

Commented:
Thanks for points!

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