Reinstalling Lion Without Erasing the Drive
Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.
When the recovery menu appears select Disk Utility. 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 click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the main menu.
Reinstall Lion: Select Reinstall Lion and click on the Continue button.
Note: You can also re-download the Lion installer by opening the App Store application. Hold down the OPTION key and click on the Purchases icon in the toolbar. You should now see an active Install button to the right of your Lion purchase entry. There are situations in which this will not work. For example, if you are already booted into the Lion you originally purchased with your Apple ID or if an instance of the Lion installer is located anywhere on your computer.
Kernel panics are usually an indication of a hardware problem, or a bad driver problem.
Since you are worried about your data, your first priority is to backup your data
Or if the backup tools fail to work in the middle, use recovery software that boots on its own CD, which is listed on the back tip through a separate link.
If that fails, it definitely is a hardware problem. Use this article to test for some hardware issues:
If there are no errors, it more likely is your RAM than anything else. RAM that works well in one operating system may fail another because of its random nature and the impossibility of testing every circuit of RAM. See my bad RAM FAQ*:
If you're able to boot, launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ If you’re running Mac OS X 10.7 or later, open LaunchPad. Click Utilities, then Console in the page that opens.
Select the most recent panic log under System Diagnostic Reports. Post the contents — the text, please, not a screenshot. For privacy’s sake, I suggest you edit out the “Anonymous UUID,” a long string of letters, numbers, and dashes in the header and body of the report, if it’s present (it may not be.) Please don't post "shutdownStall" or "hang" reports.
If you can't boot in the usual way, try a safe boot. The instructions provided by Apple are as follows:
- Be sure your Mac is shut down.
- Press the power button.
- Immediately after you hear the startup tone, hold the Shift key. The Shift key should be held as soon as possible after the startup tone, but not before the tone.
- Release the Shift key when you see the gray Apple icon and the progress indicator (looks like a spinning gear).
During startup, you’ll see a progress bar, and then the login screen, which appears even if you normally log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.
Safe mode is slower than normal, and some things won’t work at all.
Note: If FileVault is enabled under Mac OS X 10.7 or later, you can’t boot in safe mode.
Recovery HD. Repair disk twice. Message: "Can't repair this disk. Back up files, reformat." Not too confident about reformatting.
Then I would quicly back up my files as it says. It sounds very much like you about to experience a severe disk failure. At best wiping and reformatting may save it, but at worse you may end up needing a new drive.
That's where I would use a recovery tool such as Prosoft Data Rescue, or Subrosasoft Filesalvage to boot off their CD, and attach an empty external hard drive that is properly formatted and recover the data to them. Do not attempt to boot off the damaged hard drive as that will only speed its demise. Reformatting should only be done once you've made every possible effort to find if your data is recoverable or at least backed up in some reasonable fashion.
Details show "Invalid vol dir count" of 1 more than should be
And "Invalind vol file count" of 2 more than should be.
Does that give any indication of severity of problem? Can it be repaired?
Am running disk repair a 4th time. Have I done that enough and move on?
This is where a program such as DiskWarrior comes into it's own. It may well be able to fix this, maybe not. Until DiskUtility shows no errors, it has not been a successful repair.
a brody wrote:
Even so, Disk Warrior is not as good at data recovery as tools such as Prosoft Data Rescue or Subrosasoft Filesalvage. This is where I say, before you attempt any further repair attempt to recover your data.
Point taken. My mistake.
I was still thinking of the 'backing up data' phase, and then repair.