Kernel Panic that I can't get past, plus unable to start up in safemode

Question

Hi there. I was wondering if anyone had any ideas.
I was using my computer yesterday and after dinner when I turned it on I had the transparent drapes lowering over my monitor. A kernel panic with a "You need to restart your computer" in four languages. I restarted and I get the same message. So I am sort of stuck. I can't run in safe mode. I tried and I got stuck at the apple screen with the turning gear for about half an hour.
I can use the comp as a firewire target drive. And I have run disk utilities which found a number of permissions errors that were corrected but the hard disk appears fine, and I have run the other extended hardware check - I think its what comes up when you hold down D and restart and not errors were detected.
I googled the panic log - and someone had the exact same log I think and his problem was solved by a an archive and install. The only difference is he could run in safe mode. So will this work for me? I am at work now, but have a freelance projects due in two days and need to get this machine running tonight.
Here's the log:
Sun Jan 25 22:42:18 2009
panic(cpu 1 caller 0x001694C6): "vmmapunwire: entry is unwired"@/SourceCache/xnu/xnu-1228.5.20/osfmk/vm/vm_map.c:4110
Backtrace, Format - Frame : Return Address (4 potential args on stack)
0x2edefdf8 : 0x12b0fa (0x4592a4 0x2edefe2c 0x133243 0x0)
0x2edefe48 : 0x1694c6 (0x45c20c 0x34b28000 0x0 0x2edeff0c)
0x2edeff28 : 0x5ca328 (0x34b38000 0x0 0x0 0x0)
0x2edeffc8 : 0x19ebdc (0x0 0x0 0x1a20b5 0x456b128)
Backtrace terminated-invalid frame pointer 0
Kernel loadable modules in backtrace (with dependencies):
com.apple.BootCache(30)@0x5c8000->0x5ccfff
BSD process name corresponding to current thread: kernel_task
Mac OS version:
9E25
Kernel version:
Darwin Kernel Version 9.4.0: Mon Jun 9 19:30:53 PDT 2008; root:xnu-1228.5.20~1/RELEASE_I386
System model name: iMac8,1 (Mac-F227BEC8)
Thanks for any tips.

Answer 1

The panic seems associated with the boot cache. This could simply be a cache corruption problem. If you can boot into safe mode, then download a utility such as TinkerTool System - VersionTracker or MacUpdate - and use it to clear all system, user, and font caches. Reboot immediately and see if this resolves your problem. If not, then you can do the following:
How to Perform an Archive and Install
An Archive and Install will NOT erase your hard drive, but you must have sufficient free space for a second OS X installation which could be from 3-9 GBs depending upon the version of OS X and selected installation options. The free space requirement is over and above normal free space requirements which should be at least 6-10 GBs. Read all the linked references carefully before proceeding.
1. Be sure to use Disk Utility first to repair the disk before performing the Archive and Install.
Repairing the Hard Drive and Permissions
Boot from your OS X Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Installer menu (Utilities menu for Tiger.) After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported, then quit DU and return to the installer.
2. Do not proceed with an Archive and Install if DU reports errors it cannot fix. In that case use Disk Warrior and/or TechTool Pro to repair the hard drive. If neither can repair the drive, then you will have to erase the drive and reinstall from scratch.
3. Boot from your OS X Installer disc. After the installer loads select your language and click on the Continue button. When you reach the screen to select a destination drive click once on the destination drive then click on the Option button. Select the Archive and Install option. You have an option to preserve users and network preferences. Only select this option if you are sure you have no corrupted files in your user accounts. Otherwise leave this option unchecked. Click on the OK button and continue with the OS X Installation.
4. Upon completion of the Archive and Install you will have a Previous System Folder in the root directory. You should retain the PSF until you are sure you do not need to manually transfer any items from the PSF to your newly installed system.
5. After moving any items you want to keep from the PSF you should delete it. You can back it up if you prefer, but you must delete it from the hard drive.
6. You can now download a Combo Updater directly from Apple's download site to update your new system to the desired version as well as install any security or other updates. You can also do this using Software Update.