Adaptec installer permissions oddity: a follow-up

Regarding yesterday's advice on dealing with inexplicably modified permissions settings, Justin Shore correctly warns against exactly following the advice to use <chmod -R 755 System>. This changes the permissions for every file under System, whether it was incorrect or not. And there is no way to easily undo it (short of reinstalling the OS), should you be unhappy with the result. Instead, it is much preferred to change only the files that need changing. Use the <chown> command to change ownership, if needed and use the <chmod> command to change permissions. Use the <man> command (e.g., <man chown>) to learn more about these commands, if needed.

Indeed, Walter Petlevich (the person who we quoted yesterday) offers this follow-up: "A better procedure is to use <chmod 755> on each of the three directories, System, Library, and Extensions. If you follow my original procedure the Classic environment will fail to start since the suid permission on the TruBlueEnvironment file has been changed by the procedure."

Jason Warren did have success with a global, although less pervasive, change: "I logged in as root and got info on my HD. After switching the permissions for group Admin to read and write, and copying them throughout the HD, I was able to install the 2906 driver without any problems."

Similarly, Cliff Mould had the Adaptec installer problem. Specifically, he received the error message:

Unexpected permissions/ownership for directory '/System/Library/Extensions' (drwxrwxr-x clifford staff, expected drwxr-xr-x root wheel)

He used <sudo chown root:wheel /System> and <sudo chmod 755 /System> to gain root access and make the desired changes. It worked, with no ill effects so far. But again, do this at your own risk.