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

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

I didn't think mach_kernel is a file I need on my HD, so I deleted it. Now, my VMWare Fusion is not starting up my VM at all, in stead it gives me a bunch of errors because it can't find the kernel file. I recognized that this is because I deleted the mach_kernel file. I tried all online solutions but none worked. Currently, my OS X 10.8 is working fine. Now, I want to get the mach_kernel file back and put it in my HD again. How can I get that file again?

MacBook Pro, OS X Mountain Lion (10.8.5)

Posted on Oct 7, 2013 1:07 PM

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Answer 1

Oct 7, 2013 1:27 PM in response to ahmedshedeed

LOL. Good thinking.

That file was the underpinning of the entirety of OS X. You won't be able to do ANYTHING without it.

You need to boot to the recovery partition (command-R) and re-install OS X.

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Answer 2

ahmedshedeed Author

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Oct 7, 2013 1:29 PM in response to William Lloyd

My OS X restarts fine. No problems with the OS X itself at all. The problem is with VMWare Fusion. Can I get the file without re-installing?

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Answer 3

etresoft

Level 8

46,524 points

Oct 7, 2013 1:30 PM in response to ahmedshedeed

The mach_kernel file is your operating system. Your Mac won't function without it. I've never tried to delete it so I don't know what will happen. You definitely don't want to try restarting. Backup the files you want to save and reinstall the OS.

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Answer 4

Eric Root

Level 10

684,045 points

Oct 7, 2013 2:17 PM in response to ahmedshedeed

You might be able to recover it by running the combo update.

10.8.5 Combo Update

If you do recover it or reinstall, use the Terminal command below to make it invisible. Copy and paste into Terminal to avoid errors.

sudo chflags hidden /mach_kernel

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Answer 5

Barney-15E

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Oct 7, 2013 3:50 PM in response to ahmedshedeed

Did you empty the trash?

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Answer 6

ahmedshedeed Author

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Oct 7, 2013 3:54 PM in response to Barney-15E

Yes

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Answer 7

C F McBlob

Level 4

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Oct 7, 2013 3:56 PM in response to ahmedshedeed

Let me guess... you DON'T have a Time Machine either?

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Answer 8

ahmedshedeed Author

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Oct 7, 2013 3:59 PM in response to C F McBlob

I do have a time machine. The latest update is on 9/12. I can't restore from it because I'll lose all the progress since then. I'm afraid to backup to it which might take out the mach_kernel file there.

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Answer 9

ahmedshedeed Author

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Oct 7, 2013 4:00 PM in response to C F McBlob

Do you know a way where I can retreive the mach_kernel file only from my time machine?

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Answer 10

etresoft

Level 8

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Oct 7, 2013 4:05 PM in response to ahmedshedeed

You don't have to worry about that. When you restore from Time Machine, it will not remove files. You have to reinstall the OS. When you fail to startup the next time you reboot, you will have to do that. That will restore the mach_kernel file. With any luck, everything will be fixed at that point. If not, then you may need to restore from backup. But that restore will not delete the kernel file.

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Answer 11

C F McBlob

Level 4

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Oct 7, 2013 4:08 PM in response to ahmedshedeed

ahmedshedeed wrote:

Do you know a way where I can retreive the mach_kernel file only from my time machine?

Moot point if the latest back up was that far back. The Mach Kernel file was modified with the 10.8.5 update that exposed it, and the old one would be just as useless as none at all.

You need to reinstall your OS.

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Answer 12

macjack

Level 10

111,168 points

Oct 7, 2013 4:17 PM in response to ahmedshedeed

Boot up holding command-r keys into your Recovery Volume.

Choose Reinstall OS X. This will be an install "in place" and shouldn't effect any of your own data or settings.

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Answer 13

ahmedshedeed Author

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Oct 7, 2013 4:21 PM in response to macjack

I appreciate your suggestion. Are you 100% sure that it will not affect any of my data or settings?

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Answer 14

macjack

Level 10

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Oct 7, 2013 4:46 PM in response to ahmedshedeed

Nothing is 100%. That's what backups are for.

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Answer 15

Oct 8, 2013 9:16 PM in response to ahmedshedeed

You can find this file on a fresh DMG of mountain lion, you can download this via App Store, after you have this you need to mount the .dmg (MacOS Install ESD...) after that you can copy this to / .. sudo cp

Good Luck!

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