I deleted the mach_kernel file completely. How can I get it back?

Well I´ve just ran into this problem and my time machine disk got busted so here is how I got my mach_kernel file back in case you anyone with no time machine disk happens to run into this.

- Downloaded the 10.8.5 Combo update package

- Reboot my Mac into Recovery Mode (cmd+R)

- mounted the .dmg file with disk utility

- open console utility and navigate to /Volumes/OS X 10.8.5 Update Combo/

- run the .pkg file using the command

installer -pkg OSXUpdCombo10.8.5.pkg -target /Volumes/"My_HardDrive¨/

-Wait until the package shows that is succesfully installed

-Reboot my computer

I hope this helps someone

I did the same dumb thing, I found a new file on the root directory of my hard drive called mach_kernel and I panicked. I been messing around with IP altering plug-ins and I figured I did something that I shouldn't of. So I deleted it, the machine seems to run fine and I'm not having any problems with any of my programs that I checked. I did go back to my Time Machine Drive and just restored it to the root folder. I'd really not use the machine since the deletion so I don't believe there's any issues doing what I did. Hey Apple no more surprises!!

Hi, I'm in the same situation. "accidentally" deleted the mach_kernel file, and of course I don't have time machine. You suggested to reboot in recovery mode, which I was about to do when mavericks came out.

My question is: will upgrading to Mavericks automatically restore the file ?

If yes, then I'm golden, if not then I have another question: is it crucial that I restore it prior to the upgrade ? In other words, will the upgrade be affected whatsoever if mach_kernel is no longer there ?

Thanks in advance for any advice

MBP 13" march 2013 (not retina) running OSX 10.8.5

Mavericks will certainly restore that file. The only question is whether or not you will be able to reboot to get the Mavericks installer to run. Without that file, you machine won't boot. Maybe download Mavericks and install it. When Mavericks does its reboot, hopefully it will take over and clean things up.

Ok cool thanks a lot.

I deleted the file maybe two weeks ago (a couple days after the update I guess) and everything has been working perfectly fine, turning it on and off is not a problem. So I'm guessing upgrading should go smoothly... My only issue is that without it I'm not able to update my software (well, the office suite at least), it tells me that I need a OSX 10.5 or later...

Anyways, thanks again, I'll do that this weekend

I don't know what is going on with your system, but that file is your operating system.

Me neither.. But i definitely deleted mach_kernel, and haven't touched anything else since..

Little update for those interested.

Before upgrading to Mavericks I wanted to make sure that I could restart properly, and when I tried, it brought me straight to the recoveery mode with no other option of course. This was confusing to me as I turn off and on my mbp every two days basically and during the 2 or 3 week period during which I didn't have the mach_kernel file, it had never done this. The only difference I can see is that this time I chose "restart" instead of "shut down" and then booting it manually, so I don't know how much of a difference that makes but that's the only thing that changed.

Anyways, did the "install OSX", worked fine, took about one hour from start to finish and didn't lose anything whatsoever. I upgraded to Mavericks and I've updated my programs, so everything is back to normal.

Lesson learned.

I just had the same issue in 10.8.5 (and no backups!!!?!), and I managed to address it by following the instructions here:

http://www.obdev.at/articles/missing-mach_kernel-file.html

Good luck!

I deleted my mach_kernel and have spent HOURS trying to correct it. In my case my mac would boot only as far as disk utilities and wouldnt reinstall my osx (mountain lion in my case) due to an eligibility error.

•I tried resetting the PRAM

•copying my mac harddrive to an external drive via disk utility by creating a bootable disk image to see if I could start afresh

•wiping mac hard drive to attempt a clean reinstall

•internet recovery

•safe mode

and nothing worked!

In the end I wondered if it was something simple and it was! The date was wrong. It didn't show the date in the tool bar so I couldn't see it was incorrect but I opened terminal, and typed in: date and hit enter and it showed me that the was wrong. To fix this I typed in: date 072412382014 and hit enter. This set the date to 24/07/2014 12:45. Then I typed date again and enter to check and the date had been correctly changed.

Then I could reinstall without any problem!!!

I visited 3 mac shops and was quoted £39, £59 and £99 to fix this. I think you should pay to have things fixed because an engineers knowledge is worth something but £99 for the date being wrong would have been expensive in my view 🙂