Resolved (SOLVED!) Need help deciphering Kernel Panic log

[Diogones]

Hey all,

I have a 2006 2.16 C2D iMac running 10.7.5, and I experienced a kernel panic late last night. I was listening to music, browsing the net, and had a few programs open. I was suddenly assaulted with the kernel panic screen, and after a few seconds the Mac shut off.

I waited a few seconds, and then turned the Mac back on. I ran into the grey prohibitory sign, so I rebooted the Mac and attempted to use Safe Mode, but the Mac shut down while I held the Shift key.

I restarted again, this time selecting the Recovery HD partition, which successfully started up. I ran Disk Utility, which reported no errors, but I wasn't convinced. I also ran fsck -f in Terminal, but it didn't report anything strange either.

I shut down the Mac again and this time booted from a DiskWarrior USB stick I had created for just such emergencies. It scanned the drive, and found a few damaged files, which I repaired by rebuilding the file directory.

I rebooted again as usual, crossed my fingers, and lo and behold I am back in business!

I didn't waste any time after that. After ensuring I had my Time Machine backed up with the latest changes to my system, I ran TechTool Pro on my Mac, and found that the Hardware ECC Recovered range looked questionable, but I'm not sure if i should worry about it.

I did find the kernel panic log, and I wanted to know if someone here would be gracious enough to examine it and let me know what sort of problem my Mac ran into. Based on the TechTool Pro report, I suspect the hard drive, but that might not be it.

I've attached a copy of the readout from the kernel panic log in the Console.app. I've also enclosed a snapshot of the TechTool Pro test result of the hard drive in the Mac.

 

[justperry]

As far as I can tell this is not a Panic Report, it is an application Crash Report, the Application which crashed is XpcHelper, what it does I don't really know, something to do with ipc, Interprocess Communication.

Disk Utility is not really that good in repairing disks, DiskWarrior is much better.
Could have been a small problem and if it does not happen again I wouldn't worry too much.

 

[Diogones]

Thanks for your prompt and helpful reply justperry! I had a feeling that it wasn't a kernel panic report, because I did see the word "crash" in there, but I just wasn't sure what it was. I did have the kernel panic, but oddly enough it didn't create a kernel panic report, so when the "xpchelper" application crashed, it just created a log for that, but it must have been critical for OS X to function correctly, and hence the system crash.

Speaking of xpchelper, according to this helpful page from macinside:

xpchelper is the XPC helper agent. XPC stands for "X Performance Characterization", a graphics benchmark that tests X Window performance.

xpchelper performs services on behalf of the XPC IPC facility, where IPC stands for "Inter Process Communication" which refers to different programs or processes communicating with each other, usually requesting information (for example, a program requesting information from a database).

I think it was just a system hiccup like you suggested, but I'm still wondering about that hard drive ECC issue. I'm going to keep a spare cloned drive handy, in the event that the drive does crash (which is a good idea anyway).

You are also correct about Disk Utility; it's a useful tool for general hard disk tasks, but it is no substitute for a real diagnostic tool. I actually had a chance to visit a local Apple repair shop recently, and the tech there informed me that Disk Utility will not really inform you of a hard drive failure until it's practically imminent, i.e. too late. This is why I double checked with Disk Warrior and TechTool Pro.

I guess that about sums it up.

 

[Diogones]

Could have been a small problem and if it does not happen again I wouldn't worry too much.

Well justperry, I thought (and hoped) that this was a one time situation, but it appears that it is not. I got hit with another kernel panic today, and this time I found a real panic log in the Logs directory, not just a crash report. I'm enclosing the report in this post.

I'd also like to add that I did download and run smcFanControl, which reports a low temperature of around 108 to 110°F, and a high of 140° to 147°F when actively using the machine with multiple apps open. I'm not sure how healthy that temperature is for the Mac, and if that is causing it to overheat and shut down. Remember, the TechTool Pro report did rate the hard drive temperature higher than normal, but it didn't seem too much out of whack.

I also try to clean the iMac's exhaust vent in the back and the bottom fans by the speakers routinely, which involves canned air and a soft cloth to pick up stray dust.

I hope this report doesn't mean I need a new hard drive, as that is my other suspicion, again, based upon the TechTool Pro SMART test results.

 

[Diogones]

Well there were not any new crashes, and I think I might have found the solution to this problem. After checking around with a few other forums, a helper poster read my kernel panic logs and suggested that I uninstall the third-party kexts, and see if that fixed the problem.

It turned out that there was a kext leftover from a program I had deleted. VirtualBox had four kexts leftover, even though I had dragged the icon to the trash and deleted it. Thankfully, I found a helpful script from kuneri.com that instructs the Mac to remove everything related to VB.

After running that command in Terminal, I haven't had a crash since. However, just to be on the safe side, I also cloned my existing setup, and made sure my Time Machine backup was up to date.

It's possible the HDD in the Mac could be failing, but I don't see any evidence from the tests I've run so far. It really seems like I managed to fix this recurring error. However, with my backups, if the drive should fail I'll be prepared, and I won't have lost anything.

I'm marking this thread as solved. Hopefully my solutions will help others who also are suffering from kernel panics.

 

[justperry]

Well there were not any new crashes, and I think I might have found the solution to this problem. After checking around with a few other forums, a helper poster read my kernel panic logs and suggested that I uninstall the third-party kexts, and see if that fixed the problem.

It turned out that there was a kext leftover from a program I had deleted. VirtualBox had four kexts leftover, even though I had dragged the icon to the trash and deleted it. Thankfully, I found a helpful script from kuneri.com that instructs the Mac to remove everything related to VB.

After running that command in Terminal, I haven't had a crash since. However, just to be on the safe side, I also cloned my existing setup, and made sure my Time Machine backup was up to date.

It's possible the HDD in the Mac could be failing, but I don't see any evidence from the tests I've run so far. It really seems like I managed to fix this recurring error. However, with my backups, if the drive should fail I'll be prepared, and I won't have lost anything.

I'm marking this thread as solved. Hopefully my solutions will help others who also are suffering from kernel panics.

Good for you it is solved but I do have one tip for you, nothing to do about your Mac but more so on using this forum, I didn't read any of your reply posts because you don't use the quote button, next time please do so, if you would quote me for instance I can see this in my macrumors notifications.
I was just lucky to see your last post in Forum Spy, otherwise I wouldn't have noticed it.

 

[Diogones]

Good for you it is solved but I do have one tip for you, nothing to do about your Mac but more so on using this forum, I didn't read any of your reply posts because you don't use the quote button, next time please do so, if you would quote me for instance I can see this in my macrumors notifications.
I was just lucky to see your last post in Forum Spy, otherwise I wouldn't have noticed it.

There, how's that justperry? Thanks for the tip; I was wondering why so many of my posts haven't been responded to. Now I think I know why.

Cheers!

 

[justperry]

There, how's that justperry? Thanks for the tip; I was wondering why so many of my posts haven't been responded to. Now I think I know why.

Cheers!

Good job.