[G4] 10.2.5

[Snoke Jay S NPRI]

oh boy.  let me pull that wood back off the fire, it's gotten big enough...
Your analogy is ill-conceived, Tracker. File permissions are changed using the chmod command line verb all the time under UNIX, regardless of disk state.  The utility compares the permissions states of key OS files and changes them to optimum states.  Yes, there might be a little more "voodoo" going on under the hood, but effectively, this is what is happening then.  For more information on what chmod is and what it dos, open your terminal and type:
 man chmod

Changing permissions is not ill-advised. This is not the Mac OS of old. Granted - the hard drive is not unmounted during this process, but poorly designed application installations *DO* change permissions on certain key files to states other than what Apple needs them to be for best sync with the OS.  Without those permissions being in the proper states, things like zip drive USB drivers do not load because the user no longer has permission to use them IAW the permission states on the USB driver.



> To throw more wood on this fire......
> 
> Consider that you cannot change your motor oil filter while the motor is 
> running without spilling something. This is the same procedure that people 
> attempt when trying to repair permissions with Disk Utility while booted to 
> the internal hard drive. It is ill-advised to do this.
> 
> In order to make a change on the hard drive, it has to be the target of the 
> action. If it is constantly moving, you do not have a clear target and may 
> miss your point of aim. If it is the boot drive, it is in constant motion and 
> liable to cause a problem.
> 
> If you boot to a CD or external hard drive, the internal drive is in a state 
> of rest and isn't moving as radically as it would if it were the boot drive. 
> The files on the drive will be receptive to an action from outside and there 
> is less likelihood of error.
> 
> I always try to use the latest OS version CD that I can get my hands on to 
> make repairs with.
>