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Won't Boot, just circle of death

I just gave our old iMac to my son. I never had a problem with it but wouldn't you know it.

The machine won't boot completely. We tried fsck -fy in single user mode, reset the pram. It'll come up in target mode.

Disk Utility in disk repair give Error The underlying task reported failure on exit.


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Thanks Sam

I didn't put my son's fingers in the right places. No luck with that.

I did get him to try disk repair again.

He got in red

invalid node structure

volume check failed and then the underlying task etc.


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I found this information on another post. This is not the fsck -fy, but a derivative. Please try this out and see if it helps.

Boot off the OS X CD (reboot, hold C while booting).

The installer will load up, go to Utilities in the menu and run Terminal.

Type df and look for the drive that has your Mac system mounted---you'll have to unmount this. On my MacBook Pro, it was /dev/disk0s2.

Type umount /dev/disk0s2, replacing disk0s2 with whatever disk your OS lives on.

Type fsck_hfs -r /dev/disk0s2. If you umounted the wrong thing, it will complain that you can't repair a mounted drive. Go back and umount the right thing and repeat this step.

I have done a little digging and several posts on the Apple boards state that you will see that error anytime you run disk utilities from a live OS. It is not the error that is concerning as much as any stated issues in RED.

You did not mention if this is Tiger, Leopard or Snow Leopard. But as long as you use the OS-X CD/DVD, that should be fine.

I hope this is helpful.


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Try reinstalling the system after reformatting and zeroing out the drive. Then use Target mode to move your apps back on.

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Do you have a backup of your data? If yes I agree with mayer; perform a clean OS installation.

If no this is obviously cause for alarm. I would suggest running Allsoft Disk Warrior (bootable, surprisingly effective) and then Tech Tool Pro (also bootable, run a drive surface scan).

If Disk Warrior reports errors in the file system but Tech Tool reports no bad blocks allow Disk Warrior to repair the drive as it sees fit. Then backup. A every minute. Though Tech Tool didn't find any bad blocks it doesn't mean there is not something wrong with the drive or the controller. You'll want to have a good backup plan while the drive in question proves (or disproves) reliability.

If Tech Tool reports ANY bad blocks I would suggest replacing the drive. Though Tech Tool can map around the bad blocks experience tells me bad blocks are like cancer; you can make it seem better for a while but it tends to spread.

Let us know if you get this issue resolved!



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If he's giving the machine away he's probably not to worried about his data. Zeroing out the hard drive with Disk Utilities writes zeros to all the blocks and maps out any bad ones.


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