Repairing damaged hard drive with single user mode

Magnus · 6th January 2007, 22:34

Tonight I had a reason to really be thankful to Apple for putting in command line access in Mac OS X. I know, I know, some of you don't like command line stuff, but listen to this and you may change your mind.

I was installing Bootcamp on my Macbook (Core 2 Duo, 1.83GHz, 2Gb RAM) because I'm giving a presentation at work tomorrow about how you can run Windows on Mac. I already have Parallels working beautifully and I see no reason to get Bootcamp as well but what the heck, I thought, I'd show them both options.

Anyway, I got the Bootcamp installer, ran it, created the drivers disk, partitioned the Mac hard disk, and at the last screen when you should click for Bootcamp to restart the Mac, I clicked and I got the dreaded "You need to restart your computer..." message, meaning something had gone terribly wrong.

So I rebooted the Mac and held down the Option key to see if I could get into Windows to install it, so I selected the Windows XP installer CD. It booted, installed Windows without problems, installed Apple's drivers, and everything was dandy.

So when Windows XP was all set up I wanted to get back into Mac OS X (who wants to stay in Windows?) and I got that error again, same thing as before. I tried booting from the Mac OS X installer disk, same thing. I tried all things I could think of, no luck. Only thing that worked was booting back into Windows (ah, the irony!)

So what to do?

Well, I tried single user mode. Single user mode is what Apple calls booting a Mac into command line mode, without the fancy graphical user interface.

You boot into single user mode by holding down Command and S when you boot.

That went ok, and once in single user mode I typed in:

Code:

/sbin/fsck -fy

That runs the utility that checks a volume to see if it's feeling okay. After just a few seconds it started to show all kinds of error messages on the screen and after around 10 minutes it was apparently done.

And it said:

Code:

** The volume Macintosh HD was repaired successfully.

Oh, bliss!

Just to be sure, I ran the same command again and it reported no errors.

To finish off, I typed:

Code:

reboot

And the Macbook rebooted straight into Mac OS X and all works fine now.

Just to add one suggestion... before attempting anything with Bootcamp, make sure you have backed up your Mac. In this situation I had done a complete backup just before trying the installation.

istara · 6th January 2007, 23:18

That is interesting. I would also like to share some experience I had recently, when I couldn't even Verify my disk because it "couldn't unmount". I think I had found an error, then the next time I verified it it wouldn't unmount. Either way I knew there was something wrong.

So I rebooted from a partition (which I created entirely to fix the main OS partition if/when needed) and got same problem. The supposedly inactive partition "couldn't unmount".

So I went back to my OSX.4 installation CD, and used that. Bingo! That did allow me to Verify and then Repair it fine.

iDubai · 6th January 2007, 23:44

I have to bookmark this page...

Thanks for sharing man

MacUAE · 7th January 2007, 01:43

Its BETA

Well Apple beta software is better than Micro$oft any day!

Thanks for the tip

Magnus · 7th January 2007, 06:24

Quote:

Originally Posted by MacUAE

Well Apple beta software is better than Micro$oft any day!

Yes, Apple beta > M$ 3.0

6th January 2007, 22:34	#1 (permalink)
Magnus Administrator Join Date: Apr 2006 Location: Dubai Posts: 8,394	Repairing damaged hard drive with single user mode Tonight I had a reason to really be thankful to Apple for putting in command line access in Mac OS X. I know, I know, some of you don't like command line stuff, but listen to this and you may change your mind. I was installing Bootcamp on my Macbook (Core 2 Duo, 1.83GHz, 2Gb RAM) because I'm giving a presentation at work tomorrow about how you can run Windows on Mac. I already have Parallels working beautifully and I see no reason to get Bootcamp as well but what the heck, I thought, I'd show them both options. Anyway, I got the Bootcamp installer, ran it, created the drivers disk, partitioned the Mac hard disk, and at the last screen when you should click for Bootcamp to restart the Mac, I clicked and I got the dreaded "You need to restart your computer..." message, meaning something had gone terribly wrong. So I rebooted the Mac and held down the Option key to see if I could get into Windows to install it, so I selected the Windows XP installer CD. It booted, installed Windows without problems, installed Apple's drivers, and everything was dandy. So when Windows XP was all set up I wanted to get back into Mac OS X (who wants to stay in Windows?) and I got that error again, same thing as before. I tried booting from the Mac OS X installer disk, same thing. I tried all things I could think of, no luck. Only thing that worked was booting back into Windows (ah, the irony!) So what to do? Well, I tried single user mode. Single user mode is what Apple calls booting a Mac into command line mode, without the fancy graphical user interface. You boot into single user mode by holding down Command and S when you boot. That went ok, and once in single user mode I typed in: Code: /sbin/fsck -fy That runs the utility that checks a volume to see if it's feeling okay. After just a few seconds it started to show all kinds of error messages on the screen and after around 10 minutes it was apparently done. And it said: Code: ** The volume Macintosh HD was repaired successfully. Oh, bliss! Just to be sure, I ran the same command again and it reported no errors. To finish off, I typed: Code: reboot And the Macbook rebooted straight into Mac OS X and all works fine now. Just to add one suggestion... before attempting anything with Bootcamp, make sure you have backed up your Mac. In this situation I had done a complete backup just before trying the installation. Last edited by Magnus : 6th January 2007 at 22:36.

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6th January 2007, 23:18	#2 (permalink)
istara Senior Member Join Date: Jul 2006 Posts: 156	That is interesting. I would also like to share some experience I had recently, when I couldn't even Verify my disk because it "couldn't unmount". I think I had found an error, then the next time I verified it it wouldn't unmount. Either way I knew there was something wrong. So I rebooted from a partition (which I created entirely to fix the main OS partition if/when needed) and got same problem. The supposedly inactive partition "couldn't unmount". So I went back to my OSX.4 installation CD, and used that. Bingo! That did allow me to Verify and then Repair it fine.

6th January 2007, 23:44	#3 (permalink)
iDubai Senior Member Join Date: Apr 2006 Location: Hidding in Nadd Alhamar Posts: 818	I have to bookmark this page... Thanks for sharing man

7th January 2007, 01:43	#4 (permalink)
MacUAE Senior Member Join Date: Apr 2006 Posts: 353	Its BETA Well Apple beta software is better than Micro$oft any day! Thanks for the tip