Can I undo "Repair Disk Permissions" ?

Discussion in 'macOS' started by Ocean Sea, Oct 26, 2010.

  1. Ocean Sea macrumors newbie

    Jan 6, 2010
    I carried out a "Repair Disk Permission" from the OS X Install disc by mistake. I meant to do "Repair Disk" from the OS X install disc.

    According to (and the guide posted here) "Repair Disk Permission" should not be done from the OS X install disc, as it may alter changes made by by software updates.

    Is there any way I can undo my mistake?
  2. tersono macrumors 68000


    Jan 18, 2005
    You probably won't have any problems, but running 'repair permissions' from disk utility should rectify any errors.
  3. Ocean Sea thread starter macrumors newbie

    Jan 6, 2010
    Thanks for the reply tersono.

    According to the MacRoumours Guide Repairing Permissions it says the same thing.

    I did that but when I was mistakenly Repairing Permissions from the install disc it listed of 50 or more items to be repaired. Most if, not all were Air Port Utility related. But when I re-ran Repair Permissions from within OS X it didn't list any of them as being undone.

    From my limited understanding of Repair Permissions your solution should work: Repair Permissions checks an "index of permissions" against the actual permissions and changes the permissions accordingly.

    If that "index" was sourced from the Install Disc then it would be out of date in relation to Software Updates. But I am guessing it shouldn't alter the up-to-date "index" file on the system hard drive in any way?

    So when I did your solution it should have read the correct up-to-date "index" and rectified any mistakes made the first time.

    I read in a MacWorld article (from 2006 I think, under the 3rd heading) that in all recent versions of OS X, Disk Utility uses the up-to-date index on the volume actually being repaired, whether using the Install Disc or not !

    If that's correct then that would explain why I got a list of Air Port fixes the first time I Repaired Permissions (using the Install Disc) but didn't get any undo confirmation when I ran Repair Permissions for the second time (from OS X): They were valid fixes.

    If that's true then why does Apple say its best to do it from within OS X rather than the Install Disc if both methods use the same up-to-date "index" from the same source?

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