I recenty had a problem with my Apple HD and I didn’t find anything good online, so I am going to post what I did here so anyone else trolling the search engines might get some help.

Scenario:

I don’t reboot my laptop often, but I noticed that it’s running a little sluggish, so I decided maybe it’s time to give it a good restart.  I am, of course, looking over some of my notes for the two presentations I am giving in a couple of days as it does this.  As the computer starts back up, I turn away.  When I look back, it is turned off.  Odd, but my laptop has some quirks, so I give it a go again.  This time I watch.  Yup, it starts to boot and then just turns off.  Weeeeeird.

I get my handy boot/install disk and check the system log, where I see messsages like this..

kernel[0]: HFS: Runtime corruption detected on HD, fsck will be forced on next mount.
kernel[0]: hfs_swap_BTNode: invalid forward link (0xb6baad6e >= 0x0000a280)
kernel[0]: node=33456 fileID=4 volume=HD device=/dev/disk0s2

Bad juju, but hopefully not a big deal.  I pull up Disk Utility and I get this lovely message.

Invalid record count
Volume check failed
Error: The underlying task reported failure on exit

1 HFS volume checked
1 volume could not be validated or repaired because of an error.

Blah.

So I play the “I’ll look away and then it will do it” game for a while, but I can’t make it work.  I go back to the command line and use the checking tool myself.

fsck_hfs -d /dev/disk0s2

Same result. Thanks.  I, of course, run this a couple more times, ’cause, yeah, you never know.  Hah.

I do some research online and find very little.  I’m looking at some of the fancier tools and then realize I haven’t tried all of the options with fsck_hsf.  I notice it always fails at the catalog check

fsck_hfs -dr /dev/disk0s2

Ahha!  -r rebuilds the catalog.  It runs through about four checks over about 10-15 minutes, but comes out saying it’s clean.  I run one more check just to be safe, but it doesn’t detect any problems.  Cross my fingers and reboot and, viola, it works.

This probably means my disk is toast or going to be toast soon, but I’ve been monitoring the log and so far no errors, so we’ll just have to see.  I have my system backed up, so it wouldn’t/won’t be tragic to replace the drive, but it’s work I don’t really want to do if I don’t need to.

I hope this helps someone–fun with disk problems!