gray screen on boot up, posix_spawnp /usr/sbin/mDNSresponder no such file or directory

an OS X server got unhappy and seemingly did hang on bootup on the gray screen with the rotating ‘progress’ indicating.

Booting it with text mode enabled (holding command V) revealed that the machine would loop with the following error message snippets:

posix_spawnp ... /usr/sbin/mDNSresponder ... no such file or directory

ls -lsd /
0 drwxrwxr-t 43 root admin 1530 Dec 20 03:57 /

Booting into single mode (command -s) and then doing the suggested fsck and mount -uw / revealed that the permissions actually were set to:


Meaning that others have not even read permissions. This makes the mDNSresponder seemingly unhappy. I would guess that it quickly gives away its root privileges after launch for security reason. Running what the internet suggested

chmod 775 /

did fix the issue.

10 Responses to “gray screen on boot up, posix_spawnp /usr/sbin/mDNSresponder no such file or directory”

  1. Mauro Says:

    Hi Andreas,
    I would like to thank you about the booting problem with osx server. I was worried to have to do a new install, than I found your post via google. The chmod 775 fix the problem.
    I have just one question: the problem occurred when I installed the last updates. During the rebooting I switched off the usb-printer. I’m just trying to find what caused the problem: the installation of updates or the switching off of the usb-printer…

    Many thanks anyway, you save me some hours of unpleasant work.

  2. Michael Says:

    Many thanks - I had the same problems, for me totally unfathomable. Your diagnostics and fix worked simply and perfectly.

  3. Tom Says:

    Danke fuer den Tip. Super Loesung. Schnell und einfach!
    Hat mir ne Menge Zeit erspart!

  4. Martin Says:

    Many thanks, have been pulling my hair out trying to fix, couldn’t find help until here and it worked a treat.

  5. marc Says:

    worked perfectly…thank you…wish I had found this four hours ago :)

  6. Tine Belle Says:

    Hi Andreas
    I have a mac mini - running OSX 10.4.11 - yesterday - after upgrading apples suggested updates (not safari) but iTunes - some security and something else I dont use at daily basis - I experienced the same problem as described here… would your solluiton work for me as well?
    I have booted the machine with both OSX cd and disk warrior - runned all tests and there is nothing wrong…
    Thanks in advance for your answer - hopefully already today (one of my problems is that I live and work in Alicante Spain - but the machine and I are norwegian - the help I can get here is about nonexisting)
    Tine B

  7. Brendan mckenna Says:

    Beautiful! Thank you!

  8. Riadh Djebrouni Says:

    Many thanks, it also worked for me!
    I had the same problem with xserve with snow leopard server.

  9. Motti Says:

    Ran into this problem today on Leopard on my Mac Pro after restarting. My computer stays on more or less all the time, so I could not pinpoint the exact cause of the problem. I tried all the recommended chmod fixes above, repairing permissions from original DVD, etc., none of which worked. Was about to embark on reinstalling the OS or restoring from Time Machine…

    Then I saw another thread somewhere online about disk sharing of the boot drive being responsible for the issue. I remembered turning that off at some point in the not too distant past.

    What eventually worked for me was putting another HD in the machine which I occasionally use to run Snow Leopard and booting off that by pressing alt at startup. Once booted I simply navigated to my regular HD in the Finder, showed info, changed the sharing preference for ‘everyone’ from ‘no access’ to ‘read and write’, rebooted and hey presto! Back in business!

    Hope this might help someone in a similar fix!!!

  10. Edith Says:


    Thanks so much! This worked out perfectly! Thanks a million!

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