Repairing permissions: WHY and WHEN?

Discussion in 'Mac Basics and Help' started by Steven Jackson, Feb 14, 2007.

  1. Steven Jackson macrumors 6502

    Joined:
    Dec 8, 2006
    Location:
    Lincoln, U.K.
    #1
    Following on from my post about CRON tasks, I'd like to know a bit about repairing permissions...

    First, what does it do? If it's so important (and it's pretty much recommended as a cure-all whenever people post problems on these boards) why isn't it done automatically by the OS?

    Secondly, when should I do it? How often? It seems that whenever I do it, there is something to repair, even immediately after start up. Why are the permissions always wrong, and why isn't the repair permanent?

    Weighty questions for 5am, but I couldn't sleep...

    Cheers,

    Steve.
     
  2. Eric5h5 macrumors 68020

    Joined:
    Dec 9, 2004
    #2
    Yeah, that's kind of annoying, because it's almost never needed, and the only thing it fixes is file permissions, which hardly ever get messed up. It's probably a hold-over from the earlier days of OS X, when the permissions did actually have more problems and needed frequent fixing, so now it's just a superstitious "fix" that doesn't actually fix anything.

    Some of the messages you see when you run disk utility and do a "repair permissions" don't actually mean anything. It depends somewhat on the version of the OS you're using; pretty much you can ignore them. You probably will never actually need to do it, but it doesn't hurt...it's normally just a waste of time.

    As for what it does exactly, if you click on a file and do a "get info", at the bottom you'll see some info for "Ownership & Permissions". That tells the OS which files can be accessed by whom. For some reason that info used to get messed up sometimes, which could prevent apps from running properly since they wouldn't have the necessary permission to open files they needed.

    --Eric
     
  3. 1dterbeest macrumors regular

    Joined:
    Feb 14, 2006
    Location:
    Waupun, WI
    #3
    I've never done it in the many years i've used
    10.2 and 10.4. Once I did it in 10.3 and it didn't
    really do anything. I'm not sure it really fixes
    stuff except if you network the computer a lot.
     
  4. Steven Jackson thread starter macrumors 6502

    Joined:
    Dec 8, 2006
    Location:
    Lincoln, U.K.
    #4
    Fair enough, then. Still wonder why SO many people recommend it, though.

    Steve.
     
  5. Eric5h5 macrumors 68020

    Joined:
    Dec 9, 2004
    #5
    Because they heard it's what you're "supposed" to do without understanding anything about it, and then other people pick up on that and repeat it, etc. Apparently it makes some people feel better because they feel that they're "doing" something to help a problem. Understandable, but wrong. At least it won't hurt anything, like I said.

    Ironically, the one time I actually had a permissions issue, "repair permissions" wouldn't have fixed it anyway. That is to say, one of my games wouldn't update because a file was read-only, since it was copied that way from the CD. But "repair permissions" would have no way of knowing that; in that case, it was a perfectly valid setting and there could be any number of reasons why I wanted it read-only (except, I didn't ;) ). It was just a matter of changing it manually.

    --Eric
     
  6. Steven Jackson thread starter macrumors 6502

    Joined:
    Dec 8, 2006
    Location:
    Lincoln, U.K.
    #6
    Does it ever help to repair permisions, then.

    And why aren't the repairs permanent? Why would we want to keep repairing the same problematic permissions endlessly ad nauseum?

    Steve.
     
  7. gollum macrumors regular

    Joined:
    Jan 29, 2007
    Location:
    MI
    #7
    It worked for me!!!

    Couple of days ago I installed a new hard drive in my MacBook and the only thing I changed was the name of the hard drive and Activity Monitor would not open after I was up and running. Repaired permissions, Activity Monitor worked like a charm after.
    I guess there is a time and a place for it.

    P.S. That was the first time repairing permissions actually had any tangible benefit!!!
     
  8. dllavaneras macrumors 68000

    dllavaneras

    Joined:
    Feb 12, 2005
    Location:
    Caracas, Venezuela
    #8
    Consider yourself lucky then :) It hasn't done anything for me, ever
     
  9. vincebio macrumors 6502a

    vincebio

    Joined:
    Jun 27, 2005
    Location:
    Glasgow
    #9
    this topic has been discussed many times....

    some apps or 3rd party stuff you install will require you repair your permissions before the work correctly. this has been documented tons of times...Especially with Fonts and Printer drivers.

    Its overly used as a solution however...for everyday use and the time when your NOT installing anything, its totally useless.

    Running Onyx scripts regularly and keeping your mac clean and unclogged with useless files is more important for sure


    BUT,

    to dis-credit it as something you will never need is actually incorrect.
     
  10. whooleytoo macrumors 603

    whooleytoo

    Joined:
    Aug 2, 2002
    Location:
    Cork, Ireland.
    #10
    The way PackageMaker (the developer tool to build installer packages) works, it's very, very easy to build an installer that will (erroneously) change the permissions on folders it installs to. I think recent versions have taken steps to address this, but it can still happen.

    The obvious potential result is that programs no longer have permission to read from or write to crucial files and fail to function; or crash.

    Repairing permissions after running any installer mightn't be a bad step if you're worried. However, that will only help if the permissions were changed on system files or folders, it won't prevent a program tripping itself up by messing up the permissions on its own files.
     

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