Is there any maintenance worth doing on an external? Repair disk or permissions?

Discussion in 'Mac Basics and Help' started by oxband, May 14, 2015.

  1. oxband macrumors 6502

    Sep 10, 2009
    I have external hard drives I use for backups and for film editing. Is there any kind of maintenance worth doing for them? Repair disk and/or permissions? Something else? Just curious. Some are bootable and some are not.
  2. Taz Mangus macrumors 68040

    Taz Mangus

    Mar 10, 2011
    If you are not having any issues then you should be good to go. There really isn't any maintenance required for external hard drives. Make sure you backup the important data that's on the external hard drive.
  3. glenthompson macrumors 68000


    Apr 27, 2011
    The bootable drives should be tested to verify that you can run the system from them. Any data stored on externals needs to be backed up.
  4. Fishrrman macrumors P6


    Feb 20, 2009
    If they are platter-based hard drives, an occasional defragmentation would be useful.

    This would apply particularly if you use the drives with apps that like large blocks of contiguous free space (for extended disk writes) -- such as film/video editing.

    You should probably run Disk Utility's "repair disk" function on them now and then, as well. And run "repair permissions" on those drives which are bootable.
  5. mkelly macrumors regular

    Nov 29, 2007
    Repair permissions is generally unneeded and considered to be voodoo. You see it bandied around the forums a lot here, as some kind of universal solution to misbehaving hardware/software/solar flare activity.

    In reality, it's an old legacy feature from back in the day when you could dual-boot OS X and OS 9 on the same Mac. OS 9 had no concept of unix-style file permissions, and it could occasionally muck up the permissions on OS X HFS+ filesystems. Running "Repair Disk Permissions" just resets file/directory permissions to match their initial settings. Each app you install via a .pkg file leaves a .bom (bill-of-materials) file in /var/db/receipts. Repair permissions looks at each of those receipts and resets the application's file permissions accordingly.

    The thing is that some applications do change their file permissions after they've been run. Or, you may have a valid reason for changing them yourself. I've seen instances where "repairing" permissions actually broke things by denying access to shared files.

    The problem is in the wording. "Repair" implies that something is broken, and isn't repairing always a good thing to do? Reset file permissions might be a better wording.

    In any case, if you aren't installing applications via .pkg files to the external drives, you definitely don't need to bother w/repair permissions ... and if you are installing apps there, you probably *still* don't need to bother with it.

    Source: worked as an Apple tech and unix sysadmin for a very long time, and I am one with disk permissions :)

    But if you don't believe me, here's John Gruber's take on it:
  6. ratsg macrumors 6502

    Dec 6, 2010

    I have been using OS X since the 10.0 beta's, and I have never seen it repair anything.

    It continues to amaze me at the level this command has been elevated to for something which is, for all essential purposes for 10.5 and later systems, useless.

    I got into an online disagreement probably around a year ago with a gentleman who was making outrageous about the repair capabilities of the repair disk permissions command.

    I finally had to go hunt it down myself. I found an Apple link which has expired, but had been archived in the Wayback Machine and was still available there. It stated pretty much verbatim what your article says.

    The disk repair permissions was for use on dual boot systems, as the old Mac OS 9 had no concept of unix drive permissions and would occasionally mess them up.

    Unless someone has some magic tool, and please share if you do I still have Classic apps I use, that allows 10.5 and later systems to boot Classic and/or dual boot, repair disk permission really serves no real purpose in the current Mac OS X world.
  7. ratsg macrumors 6502

    Dec 6, 2010
  8. GGJstudios macrumors Westmere


    May 16, 2008
    Some people repair, or recommend repairing permissions for situations where it isn't appropriate. Repairing permissions only addresses very specific issues. It is not a "cure all" or a general performance enhancer, and doesn't need to be done on a regular basis. It also doesn't address permissions problems with your files or 3rd party apps.
    There are times when repairing permissions is appropriate. To do so, here are the instructions:
    If repairing permissions results in error messages, some of these messages can be ignored and should be no cause for concern.

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