iMac Leopard won't reboot - Disk Utility Repair Failed

Hard drives are parts that Apple buys from suppliers, so they are the same as on any other computer. They can definitely fail or have disk directory errors, even on a Mac. That's why it's a good idea to do regular backups to an external drive (using Apple's Time Machine or other utility). If you were using Time Machine, you would be able to recover to within the last hour.

Also, there should not be any reason to run things like +cache cleaners+. There are automated processes that run in the background. In Leopard, if a maintenance process does not run because the Mac is shut down or sleeping, it gets scheduled to run after the Mac comes back on.

If you have a program like Disk Warrior (by Alsoft) or TechTool Pro (by Micromat), you can try to use it to repair your drive. If you have an external drive with enough free space, you can install Mac OS X on it, start up from it, and attempt to recover your data from the internal drive. Sometimes you can still access the drive, although you cannot start up from it.

AKARUPERT wrote:
My 20" iMac purchased this year froze up today after I was using Leopard Cache Cleaner.

Wouldn't reboot hot, cold, power off- power on, and then not even in safe mode.

Why were you using LCC? Did you have some problem with your system?
I see you are only running 10.5.2 rather than the latest version.

Used the Install DVD - after three (3) times I got in to Disk Repair - S.M.A.R.T. Verified BUT:

Error messages are:

"Invalid sibling link"
"Volume check failed."
"Error: Filesystem verify or repair failed."

What am I supposed to do now? I guess I can reinstall Leopard but I don't want to lose all of my files on the hard drive.

Help! This isn't supposed to happen on a Mac!

It happens rarely, but it does happen. I presume you have no backup.

Your HD data may be intact and something else could be amiss.
See if you can boot into the Target mode and look at your HD from another computer.
Or you can download and burn a Ubuntu Live CD, boot into it and view/copy your HD files to another external drive.

I had the precisely same problem sometime back. Disk Warrior fixed it for me.

http://www.alsoft.com/DiskWarrior/index.html

Time Machine is not ideal for this type of one-time backup. The advantage of Time Machine is for continuous ongoing incremental backups every hour.

While the 20" iMac is connect in target disk mode, you should run Disk Utility on the 24" iMac. Use Disk Utility to make a disk image of the 20" iMac's damage volume, and store the image file on the 24" iMac's hard drive (assuming there is sufficient space). After the disk image file is created, make sure it mounts and inspect it to see if there are any important files missing. Once you are comfortable that you have your valuable files in that disk image, use Disk Utility to erase the 20" iMac's hard drive. Then use Disk Utility's Restore tab, using that disk image file as the Source and the newly erased 20" iMac's hard drive volume as the Destination. You should check the box for +Erase destination+ to make the copy exact.

After the Restore completes, restart the 20" iMac in regular mode and see if it starts up from its internal hard drive. There is a good chance of file damage that may prevent startup from that drive. If that's the case, startup from the Mac OS X installation disc and run an +Archive and Install+ option installation. This will give you a fresh system while retaining your user data and account.

Manually copying your user folder to the 24" iMac was the right thing to do, since making a disk image apparently does not work. Now you have a backup of your valuable user files, no matter what happens. At worst, you'll need to reformat (erase) the drive on the 20", reinstall the OS (starting up from Mac OS X installation disc) and then your apps, and finally restore the data you just copied off. And that may be your next step. Just reconfirm you have ALL of your data that you need copied off (and that you did not have any files saved on the drive outside your user folder).

And if you have decided to do an reformat of the drive and reinstall, there would be no harm in trying the Single User Mode solution from macosxhints.com. If it works with acceptable results, you've saved some time and effort. If it does not, you've only wasted a little time and effort.

There must be a way - any suggestions?

I fear I'm repeating myself, but you should try Disk Warrior.

Disk Warrior will not help if you can't boot from the optical drive.

I think there may be a physical hardware problem with the 20" iMac's hard drive. This can sometimes cause problems with booting from any device on the bus. You might try starting the 24" iMac in FireWire Target Disk Mode, connecting to the 20" iMac, and starting up the 20" iMac with the Option key held down.

If that gives you Startup Manager, see if you can select the 24" iMac's hard drive as the startup drive. If you can startup that way (run the 20" iMac off the 24" iMac's hard drive), you can use Disk Utility to see if the 20" iMac's hard drive is accessible, and try to erase the drive.

At least you were able to copy off your data before the problem got worse.

That's good.

If your wife is getting an external drive, you should use it temporarily connected to your 20" iMac (while it's still running). Then use a cloning utility (Carbon Copy Cloner or SuperDuper) to duplicate the internal drive onto the external drive. The duplicate should be bootable, so change the startup drive in System Preferences Startup pane, and try restarting from it. If that works and everything (all of your user data) is there upon inspection, this backup will be better than your previous one, because you can boot from it if necessary.

Once started up from the external drive, you can run tests on the internal drive. If everything seems to be OK and the iMac runs fine off the internal drive, I guess you should keep using it as is. I don't know what the problem was. If you unplugged it while trouble-shooting, it may have done an SMC (power management) reset.

http://support.apple.com/kb/HT1543

It would be a good idea to get a permanent external drive for the 20" iMac to use continuously with Time Machine. Then, even if the problem recurs, you'll have a backup of the entire drive to within one hour, and you can use it to recover.

Apple probably does not want the liability from including a tool that does what DiskWarrior (and Tech Tool Pro) does. DiskWarrior does a fine job of recovery, but it can potentially make the problem worse. Even if there is no existing problem and you are doing a regular optimization run, if there's a power outage (or some other problem) while DiskWarrior is writing the new optimized disk directory data, that can totally mess up your volume. Better to have the official position of (1) do your backups with Time Machine. (2) If you have a problem that Disk Utility cannot repair, (3) erase the volume. (4) Use your Time Machine archive to restore the complete volume to within one hour of the failure event.

Apple certainly has enough money in the bank to buy Alsoft or Micromat, and then include either utility with new Macs. If that's what they wanted to do...