tjk

Q: mach_kernel appeared

Hi all,

 

Just noticed mach_kernel appeared between Library and System at main level of HD. Don't think it was there before latest security update, but don't know for sure. Anyway, the question is, what to do about it. I found an old thread with the same issue back in 10.8.5 in 2013, but don't know if the fix would still be the same. Specific instructions appreciated. Also curious if others have found this issue.

 

Thanks!

Posted on Mar 10, 2015 8:24 AM

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Q: mach_kernel appeared

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  • by BobHarris,Helpful

    BobHarris BobHarris Mar 10, 2015 9:00 AM in response to tjk
    Level 6 (19,655 points)
    Mac OS X
    Mar 10, 2015 9:00 AM in response to tjk

    DO NOT mess with /mach_kernel.  It is the heart of Mac OS X and absolutely essential.

     

    mach_kernel should have the 'hidden' as shown below via the 'ls' command in an Applications -> Utilities -> Terminal session:

    /bin/ls -leO@ /mach_kernel

    -rwxr-xr-x@ 1 root  wheel  hidden 8394688 Dec 17 22:06 /mach_kernel

        com.apple.FinderInfo         32

    Did you tell your Finder to show hidden files?  If so that would explain why you are seeing mach_kernel

     

    It does NOT  hurt anything if you see mach_kernel, as long as you DO NOT mess with it.  If you can avoid that temptation, then you can leave it alone.

     

    You might consider running Applications -> Utilities -> Disk Utility -> Repair Permissions.  That might fix up the 'hidden' flag if you have not told the Finder to show hidden files.

  • by Kurt Lang,Solvedanswer

    Kurt Lang Kurt Lang Mar 10, 2015 9:26 AM in response to tjk
    Level 8 (38,009 points)
    Mac OS X
    Mar 10, 2015 9:26 AM in response to tjk

    The file should be hidden. Open Terminal and copy/paste the following command into the Terminal window:

     

    sudo chflags hidden /mach_kernel

     

    Press return. It will ask for your admin password. Enter that and press enter again.

  • by tjk,

    tjk tjk Mar 10, 2015 2:45 PM in response to BobHarris
    Level 7 (24,244 points)
    Mac OS X
    Mar 10, 2015 2:45 PM in response to BobHarris

    BobHarris wrote:

    Did you tell your Finder to show hidden files?  If so that would explain why you are seeing mach_kernel

     

    You might consider running Applications -> Utilities -> Disk Utility -> Repair Permissions.  That might fix up the 'hidden' flag if you have not told the Finder to show hidden files.

     

    Didn't tell Finder to show hidden files, it just appeared, and like I said, I think it just appeared after I ran the security update yesterday.

     

    I ran RP right after the update and it only showed the usual benign files.

  • by tjk,

    tjk tjk Mar 10, 2015 2:47 PM in response to Kurt Lang
    Level 7 (24,244 points)
    Mac OS X
    Mar 10, 2015 2:47 PM in response to Kurt Lang

    Before I hide it though, do you know for sure it's in the right place?

  • by MrHoffman,Helpful

    MrHoffman MrHoffman Mar 10, 2015 4:30 PM in response to tjk
    Level 6 (15,637 points)
    Mac OS X
    Mar 10, 2015 4:30 PM in response to tjk

    tjk wrote:

     

    Before I hide it though, do you know for sure it's in the right place?

     

    Based on your description, the mach_kernel file is in the correct place.  mach_kernel exists in the root directory of your file system, on the disk you boot from.  If you have only one disk in use in your file system, then mach_kernel will be located in the root ("/") directory of that disk.

  • by tjk,

    tjk tjk Mar 10, 2015 5:25 PM in response to tjk
    Level 7 (24,244 points)
    Mac OS X
    Mar 10, 2015 5:25 PM in response to tjk

    Thanks Kurt, Bob, and MrH!

  • by Kurt Lang,

    Kurt Lang Kurt Lang Mar 10, 2015 7:42 PM in response to tjk
    Level 8 (38,009 points)
    Mac OS X
    Mar 10, 2015 7:42 PM in response to tjk

    You're welcome.

  • by Rhobes,

    Rhobes Rhobes Mar 12, 2015 9:55 AM in response to tjk
    Level 1 (0 points)
    Mar 12, 2015 9:55 AM in response to tjk

      I had the same problem with additional problem.

     

      I have 10.9.5 & just downloaded the security update(2015-002) and also now have this kernel in the root level of Mac HD. I almost trashed it, then thought I better come here to see if there is any info on it.

     

    So I did the terminal thing, entering: sudo chflags hidden /mach_kernel, hit return, and I get this:

     

    Sorry, try again.

    Password:

     

    I have don't have a password on my system, and have used terminal before without a password and it worked fine. I normally hit return for the password but now I can't do this. Do I have to create a password to follow through on this?

     

    Thanks

    Robes

     

    System Specs:

     

    2010 (mid May) iMac 27”/4850-512M

    Processor: 065-9233 2.8GHz Quad-Core Intel Core i7;

    Memory: 065-9266 8GB 1066MHz DDR3 SDRAM-2x4GB;

    Hard Drive: 065-8407 2TB Serial ATA Drive;

    Graphics: 065-8981 ATI Radeon HD 4850 512MB

    OPTICAL DRIVE 065-9410 8X DOUBLE-LAYER SUPERDRIVE

    OS: 10.9.5 Mavericks

  • by Kurt Lang,

    Kurt Lang Kurt Lang Mar 12, 2015 11:28 AM in response to Rhobes
    Level 8 (38,009 points)
    Mac OS X
    Mar 12, 2015 11:28 AM in response to Rhobes

    It sounds like you may have upgraded your Mac from Snow Leopard or earlier. In those versions of OS X, you can have a null admin password. If you upgrade from there, it remains that way. However, you can't have a null password for Lion (may have started with SL) and later for the Terminal. Your admin password must have some kind of character to actually type in. You can't just press the Enter key and continue.

     

    Or, you're in a non admin account. Entering the password for a Standard account isn't what Terminal is looking for. It wants the admin account password.

  • by Rhobes,

    Rhobes Rhobes Mar 12, 2015 12:03 PM in response to Kurt Lang
    Level 1 (0 points)
    Mar 12, 2015 12:03 PM in response to Kurt Lang

    I did upgrade from SL to Mavs. I went in & created a password and that allowed me to enter the Terminal command and the mach kernel is now hidden.

    Thanks

  • by Kurt Lang,

    Kurt Lang Kurt Lang Mar 12, 2015 12:14 PM in response to Rhobes
    Level 8 (38,009 points)
    Mac OS X
    Mar 12, 2015 12:14 PM in response to Rhobes

    Excellent.

  • by powerbook1701,

    powerbook1701 powerbook1701 Mar 14, 2015 9:57 AM in response to Kurt Lang
    Level 3 (571 points)
    iWork
    Mar 14, 2015 9:57 AM in response to Kurt Lang

    Well, I too just applied the 2015-002 update and noticed that file appeared in the Computer tab. My Mavericks was updated from SL about a month ago.

  • by tjk,

    tjk tjk Mar 14, 2015 10:01 AM in response to powerbook1701
    Level 7 (24,244 points)
    Mac OS X
    Mar 14, 2015 10:01 AM in response to powerbook1701

    Just fyi, Kurt's solution worked perfectly.

  • by powerbook1701,

    powerbook1701 powerbook1701 Mar 14, 2015 10:13 AM in response to tjk
    Level 3 (571 points)
    iWork
    Mar 14, 2015 10:13 AM in response to tjk

    So, does this mean there was minor bug in this update that didn't get caught? I'm guessing others have this (at least those that went from SL to Maverics) probably have this but haven't noticed yet.

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