Permissions 101

My intention with this thread is to try to understand a little more about Mac OS. My questions may be perceived as stupid and elementary, but I sincerely want a deeper understanding of my Mac in order to get maximum performance out of it. So I'll start with Permissions... What causes permssions get changed or corrupted? What are the things to avoid in order to not change them? Which is the best way to repair them...using Disk Utility without the install disk, using Disk Utility WITH the install disk, or using Onyx to repair permissions? Do all 3 methods achieve the exact same results? I have just completed a clean wipe, format and install of Mac OS 10.6.8 and I want to stick with Snow Leopard. I have fresh installs and their updates of all my Apple and 3rd party apps. I have set up Outlook and Mac Mail accounts. Before I activate Time Machine and set up Carbon Copy Cloner on an external hdd, I want to clean up everything so that I have a pristine initial TM backup and CCC bootable backup. By the time I had done all my installations, there are already permissions that have been changed or whatever it is that happens to them. That made me wonder how that happened although I haven't done any serious computing yet. Thanks in advance.

I haven't purchased CCC yet. Do I install it on my external hdd and then treat it like an internal hdd and load my OS, apps and their updates there...or does it supposedly work like Time Machine and copy over from the internal hdd?

Start with this link:

Troubleshooting permissions issues in Mac OS X


Please take note, that the utility does NOT repair permissions in your home directory (you need to use the reset password utility to do that, oddly enough).

Also, all the methods you mentioned are identical. Oh and I believe that rebuilding permissions is far too oft recommended, and no where near as useful on OS X as it was in prior Apple OSs (OS9 etc)

Dysfunction said:

Also, all the methods you mentioned are identical. Oh and I believe that rebuilding permissions is far too oft recommended, and no where near as useful on OS X as it was in prior Apple OSs (OS9 etc)

Click to expand...

Agreed. Very rarely are permissions the root of the issue.

I don't think your question is elementary at all. In fact, it's great to see people interested in learning more about how OS X works. So, let's start. What causes them to change? The answer to that, however frustrating, is "anything." As long as something as the rights to do so, anything can change permissions. They aren't difficult to change if those privileges are gained so coming up with an easy answer for this one is near impossible. That said, very few things will change permissions maliciously.

As noted, permissions can change quite easily which would be why they appear to have been modified so easily. However, most of the permission fixes that DU reports won't seriously hamper the operation of OS X. While it might be worth fixing at some point, you don't need to watch them like a hawk.

Thank you both for that...learned quite a bit. I think I was trying to compare it to the Registry in a Windows OS. Does anybody have any input regarding Carbon Copy Cloner?...(please see OP).

I haven't purchased CCC yet. Do I install it on my external hdd and then treat it like an internal hdd and load my OS, apps and their updates there...or does it supposedly work like Time Machine and copy over from the internal hdd?

Click to expand...

You install CCC on your Mac's hard drive just like any other application. It then will clone the contents of your hard drive including the recovery partition to an external hard drive. In the process it will render the external hard drive bootable so that you can boot from it in case of an emergency. It will do a complete copy the first time it runs but thereafter it only copies the changes. The external hard drive has to be formatted as Mac OS Extended Journaled using the GUID scheme.

Wow...easy!. Thanks...I love this place.