boot fails . Too many corpses. XOS 10.13.4

[Happy-Granddad]

David Batten 11 April 2018
My iMac suddenly fails to boot. I recently upgraded from 10.13.3 to 10.13.4. The Verbose boot gets into an unending production of messages like "task [nnn] failed'; too many corpses" .

I can't get into Safe Mode. Recovery mode is OK but I'm unsure what to do. Target mode allows my MacBookPro (also running 10.13.4) to see the failing machine's main drive and even make changes.

There has been a lot of activity on this forum and other support websites suggesting that .kext files are to blame. The instructions to clear the fault are many and various, and are either beyond my Terminal experience, contradictory, or incomplete (missing steps).

Is there now a clear answer to what the problem is and a straightforward way to solve it?

I have good TimeMachine backups, but the words 'erase the disk and reload the OS' are a bit vague for something so potentially devastating!

Thanks for helping
David

 

[MacInWin]

David, welcome to the forum. Given that you can get into the Recovery Mode, once there you can run Disk Utility and select in the left hand column the name of the internal drive in your machine, then click on First Aid to test it. Assuming it's ok and passes the testing, then you can exit Disk Utility and do the Reinstall macOS from the main menu and it should leave you with all your data safe and a new operating system installation, fixing the problem for you. But even if it doesn't, and it wipes out your data, you can restore from the TM backups you have. It's not really that intimidating. If at the first boot after reinstall you see the "Welcome" screen and get offered to migrate your data, take that option at the very first time it is made, tell it to use the TM backups and when it is done, you should have everything back. And that's all there is to it. Good luck with it!

 

[Happy-Granddad]

David, welcome to the forum. Given that you can get into the Recovery Mode, once there you can run Disk Utility and select in the left hand column the name of the internal drive in your machine, then click on First Aid to test it. Assuming it's ok and passes the testing, then you can exit Disk Utility and do the Reinstall macOS from the main menu and it should leave you with all your data safe and a new operating system installation, fixing the problem for you. But even if it doesn't, and it wipes out your data, you can restore from the TM backups you have. It's not really that intimidating. If at the first boot after reinstall you see the "Welcome" screen and get offered to migrate your data, take that option at the very first time it is made, tell it to use the TM backups and when it is done, you should have everything back. And that's all there is to it. Good luck with it!

" Just when it all seemed to be going so well ....... "
I did what you suggested, MacInWin:-

Booted into Recovery mode and ran Disk Utility on the hard drive. Ran for barely 5 minutes and reported all OK.
Exited and selected Reinstall OS and was offered High Sierra. OK. Agreed the License. Selected the HD. Progress?
about 10 minutes remaining. black screen white screen Apple logo and progress bar
Installing . about 45 minutes remaining
after 22 minutes,
Installing in progress . calculating time remaining
Installing . about 21 minutes remaining . Very slow progress bar . got below 10 minutes and I took my eye off the ball
Next time I looked I have a white screen with a black apple and a BLACK progress bar going nowhere.

I will of course let it 'run' for another hour, but I think I still have a problem. Next step will be to re-boot Verbose

 

[Raz0rEdge]

How old is this iMac? These types of issues are usually indicative of a failing hard drive.

 

[Happy-Granddad]

It's a refurbished iMac dating from about 2013, I think.

I'm inclined not to think it is simply a failing disk, because the mode of failure involved the unending generation of error messages about 'too many corpses' which a couple of hundred 'me too' reports suggested the problem is widespread, and some apparent procedural solutions gave me hope, if only I could understand them.


I've just this minute abandoned the static screen and rebooted in Verbose mode. I still get "Too many corpses being created"

Some proposed fixes involve deleting some .kext files, but I don't know which ones, nor how to identify any 'hidden' ones. I wonder, too, if I have to use the scripts being suggested, of if I can achieve the same thing by booting in Target mode to my MacBookPro (which connects fine).

The literature is voluminous, but not very clear.

David

 

[harryb2448]

What type of drive is in your iMac? Platter, SSD, Blade or Fusion?

 

[Happy-Granddad]

Not sure how to define the disk.

It is a 1TB drive, and not SSD.

 

[MacInWin]

The installation process is very lengthy, maybe well over an hour on a spinner drive. And from what I can see, reinstallation is the best way to deal with the issue. But it's up to you if you want to keep trying other ways. Just be aware that mucking about with kext files can lead to a very unstable, un-useable system.

 

[Happy-Granddad]

MacInWin I agree with you completely. In other threads I have seen strong assertions that deleting some .kext files will completely resolve the issue. But without an understanding of the diagnosis and the 'fix' procedures it all seems a bit like alchemy, which is why I've sought advice here.

Your convincing argument was that I should reinstall. On that basis I have booted to Recovery, used diskutil to check the hard drive (no problems found); reinstalled HighSierra (took ages and then totally froze for over an hour with white screen and black stationary progress bar. Aborted that and re-booted - same problem.

Booted in Single User mode and ran the script suggested in the Mac Diagnosis page in this Forum. First time, it said successful, disk contents changed; ran the script again, it said successful. Typed in exit and the system proceeded to boot in normal mode - same problem.

So I have tried the Reinstallation route and it didn't solve the problem.

I read somewhere that the disk should be wiped clean before doing the reinstall. I'm now desperate enough to try this, but how do I do it, and will there still be an image of High Sierra available to install?

You can see that I'm not a great MacOS technician. Truth be told, I worry that I'll destroy something. But it seems I have little to lose ...

I'm grateful for your help and patience. What can I try next?

David

BTW just off to bed: back in about 8 hours ...

 

[ferrarr]

Use Target Mode again and use your MBP to boot from the iMac drive.

It certainly sounds like the iMac drive is dying. But, you would need to give up more details about the iMac to confirm.

 

[Happy-Granddad]

Sorry, Ferrar, I don't understand how to use Target mode to do that. (I'm actually not really understanding what 'that' is.)

BTW I'm not deliberately withholding details about the Mac hard drive - I just don't know how to get more from a dead Mac.

 

[MacInWin]

IN your first post you said the MBP could get to and make changes to the iMac drive, so you could then use Disk Utility to test the iMac drive from the MBP, and if it's good hardware, then you can reboot the iMac in Recovery Mode and reinstall to the iMac again. I think you jumped the gun in cancelling the installation last time. It is, as I said, a very slow process, particularly on a spinning hard drive.

 

[Happy-Granddad]

Hi MacInWin - I guess it's going to be a late night for me.

I mentioned accessing the Mac from the MBP by way of Target Mode to show that there is information and structure still on the Mac. It also indicates I could alter the files on the Mac if necessary.

When I described the use of dskutil and the little disk-checking script and the subsequent attempt to reinstall the HighSierra OS, it was in the context of having done, in one case a Recovery Boot, and in the other a SingleUser boot.

In each case of reinstallation that I've tried, there seems to be continuous progress (indicated on the progress bar) initially quite excitedly, and subsequently almost infinitesimally, covering perhaps an hour and 20 minutes. Then there is a transition to a white screen showing a black Apple logo and a black progress bar which showed no change for over an hour.

I'm now going to do a Recovery boot and let it run overnight while I am sleeping (!) just in case you are right that it is my impatience that is at fault here.


I didn't understand Ferrar's post about using the MBP to boot from the iMac drive.

I'll be back!

David

 

[ferrarr]

Sorry, Ferrar, I don't understand how to use Target mode to do that. (I'm actually not really understanding what 'that' is.)

BTW I'm not deliberately withholding details about the Mac hard drive - I just don't know how to get more from a dead Mac.

Shut your MBP down. Turn the iMac off. Then turn turn the iMac on, and hold down the "T" tp get into Target Disk Mode. Connect the iMac to the MBP (you said you used Target mode) with the FireWire cable, if the drive is good, you can then turn on the MBP, and hold "Option" down, you will then get your boot options. Select the drive in the iMac.

Also, if the drive is dead, even only a portion of it, the recovery partition could still work. Which is why we all believe he drive is dead.

 

[Happy-Granddad]

Well, I let the Reinstall in Recovery mode continue overnight and the screen is still showing a dead black progress bar.

Thanks to ferrar for the explanation of booting the MBP from the iMac via Target mode. As I understand it, if the boot fails it will show that the iMac disk is faulty; and if it succeeds we will not have an answer for the iMac problem. Both outcomes will necessitate a trip to an Apple support store.

Since my business is totally dependent on the accounting and other software, normally synch'ed on 2 machines, I am too afraid to risk cross-contamination of my single useable system.

I'll let someone at the Apple shop try that manoeuvre using their own kit!


My thanks go to all of you for your support and advice. I will come back here in due course and let you know how I get on.

David

 

[Happy-Granddad]

From the OP: I was getting no further with a soft fix so I bit the bullet and took my iMac down to a local workshop where they do nothing but repair Macs. They very soon concluded that it was most probably a fringe-malfunctioning HDD. Nothing showed up on diagnostics, but I was persuaded that the disk was well past its 3 score years and ten.

These guys opened the iMac, gave the fan and everything else a thorough clean, and installed a 500GB SSD. They re-installed HighSierra .3 and I took the machine home, installed HS .4 and restored everything from my dual Time Machine backup drives. All my key applications restored perfectly, and all synchronisations with my MBP were intact.

Just reporting a happy outcome, and acknowledging the good advice I was given here.

David