To do this, press the Command key and space bar on the keyboard, type “Disk Utility” in the Spotlight search box that appears and select the Disk Utility application when it pops up in the results list. Repairing a Mac’s disk permissions is often advised as a basic troubleshooting step to fix these types of problems. Incorrect permissions can occasionally cause erratic behavior like files that cannot be saved, programs that will not open or text that is scrambled. With time and use, actions like installing or uninstalling programs may inadvertently alter these permissions from their initial state. Among other things, having the correct permissions in place ensures that an installed program cannot modify read-only system files, and that one user’s personal files are kept private from others with user accounts on the same computer. OS X uses a system of disk permissions to control who and what have access to files and folders on the computer - and it essentially keeps a master list of what the permissions for each file should be.

In Mac OS X, what does the “Repair Disk Permissions” function of the Disk Utility app actually do?Ī.

Mac disk utility repair permissions