Unrepairable disk errors on Mac partitions caused by Bootcamp Windows updates?

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Level 1

8 points

Unrepairable disk errors on Mac partitions caused by Bootcamp Windows updates?

Hi,

I'm new to this discussion board and relatively new to Mac. I have a MacBook Pro purchased a couple of months ago. I installed bootcamp and Windows 7 on a separate partition because I have some programs I need to run that don't run on OS X. This works fine most of the time but on three occasions now, after Windows has done a critical update, I can no longer boot into the Mac partition. I get the following disk error "Incorrect number of thread records", which disk utility can't fix. I also tried TechTool Pro on one occasion but that didn't work. I have looked through discussion boards and found similar errors discussed but no solutions (and no-one has associated Win updates with the problem, but there seems to be a clear correlation in my case).

So each time I have reinstalled OS X. This last time I was really careful to do a Time Machine backup before any Windows updates so if the problem occurred again, I could easily restore my files and settings. Now here's the kicker. Windows update just did a few more critical updates and again the same disk error came up. No problem, I have a backup. So I reinstalled OS X (again) and went to restore my files. But the HFS partition on my external hard drive I used for time machine didn't appear... I then went into disk utility and found that this partition had also been corrupted!! Clicking on 'Verify Disk' gave the error "Keys out of order", which unsurprisingly could not be repaired. So now it looks like I'm going to have to start from scratch again, and every time Windows wants to update, I'll have to make sure my external hard drive is not plugged in and do a complete reinstall of OS X + restore of my files and settings. Seems a bit ridiculous!

Any help would be greatly appreciated.

Thanks.

MacBook Pro, Mac OS X (10.6.7)

Posted on Sep 26, 2011 6:38 AM

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Answer 1

Sep 27, 2011 5:48 AM in response to jonom

I have a similar problem and I have the feeling that it is something to do with changing to the Windows partition.

My machine is a Macbook Air puchased about January 2011 running Snow Leopard and Windows 7 under Boot Camp.

In March I couldn't repair my Mac partition of the SSD after several boots between Windows and OSX and the Apple technician advised me to reformat the OSX partition. I did this. Since then I have used Windows infrequently. Yesterday I did so again after a long time. Again the disk became corrupt with the message "Keys out of Order" and was not repairable either with the disk utility. Now command-s doesn't seem to give a terminal screen.

Throughout I have had no problem with the Windows partition.

I am just about to reformat and reinstall the OSX partition again.

Also I noticed that a few years ago someone sent his Macbook with a similar problem for repair and the logic board was replaced.

Does any Mac guru know if there is a known bug or hardware problem that could explain this? I gather that SSD defects are not likely to show this problem.

Thanks for the information

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Answer 2

jonom Author

Level 1

8 points

Sep 27, 2011 6:20 AM in response to georgekildare

I think I may have found the problem. Apparently Windows Update creates temporary install folders on whatever partition has the most free space available (regardless of whether the partition is on an external hard drive or in a different file format!!!). This has been discussed in other forums e.g.

http://social.technet.microsoft.com/Forums/zh/winserverwsus/thread/b65af122-f4db -4053-a22d-f2b1081cc01e

In fact, at one stage I noticed about 20 directories in the root of the Mac partition with random-number-type names. At the time I didn't know what they were, but now I'm pretty sure that's what they must have been. Unsurprisingly, when Windows writes to a HFS partition (presumably with NTFS encoding) it wreaks havoc with the HFS file system.

So the solution with respect to an external drive formatted in HFS format is simply to make sure the drive is not physically connected when doing a Windows update.

The solution for the Mac OS partition is a more tricky. My plan is to reinstall OS X on a minimally-sized HFS partition and then have a much larger Windows partition (i.e. store my data on the windows partition). The other option would be to have a large third partition for data in FAT format so that both OS X and Windows can access it... then if Windows writes to that partition it shouldn't mess up the file system.

Also, I noticed that in Windows, any HFS drives/partitions are always reported as having 100% free space regardless of how much is actually on there. So to avoid the problem, the entire size of the HFS partition probably has to be less than the amount of free space on an NTFS or FAT partition at the time of Windows updates.

So far I couldn't find any way of specifying where Windows puts these temporary install folders... of course that would be the best solution, so if anyone knows how to do that please let me know.

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Answer 3

Sep 27, 2011 6:21 AM in response to georgekildare

Correction. When I try to reinstall OSX this time, the relevant partition is invisible. I can only see the Windows one. It looks as if I will have to contact Apple support and in the meanwhile revert to Windows.

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Answer 4

jonom Author

Level 1

8 points

Oct 4, 2011 8:13 AM in response to jonom

I tried making the HFS partition small, but still this doesn't work!

However, I did find out from http://hints.macworld.com/article.php?story=20090828100459305 that it is possible to unmount the HFS volume before running Windows update. This will most likely fix the problem without needing to worry about partition sizes.

In Windows:

Start > Run ‘cmd’ as Administrator

mountvol f: /d

where f: is the HFS drive letter and /d specifies to delete (i.e. unmount) the volume.

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