How to resolve permission issues in Mac OS X

I am facing problems in saving files in My Mac system from last few weeks. It always prompts an error message saying simply that the file can not be saved. I tried a variety of things to fix it – rebooting, saving the file in different folders but, it didn't work. One of my friends suggested me to repair file permissions. It really worked and fixed the problem. Now, I can save files easily.

What are file permissions, and why are they important?

Every file on Mac file system has specific file access permissions. File permissions are a set of rules that specify which users are allowed to read, write, and execute the contents of a file or folder.

It can be set for a file’s owner, owner group, and for all users on the computer. Mac OS X also uses a set of extended file permission attributes, which gives additional access privileges to users.

If a program does not have the correct permission to access to a file, the program does not work properly and may cause issues. The unpredictable behaviour in one program can cause unexpected behavior in other applications.

How does verify/ repair disk permissions work?

Every installed application has a specific type of log file, which keeps track of access permission for each file of the program. Verify/ Repair Disk Permissions check values listed in log files and change file permissions for files to read and write.

Disk Utility

How do I verify/ repair disk permissions?

1. Open Disk Utility, It is stored in the Utilities folder (within your Mac’s Applications folder). You can open it by searching for Disk Utility in Spotlight.
   
2. In the source list (left-hand side of the Disk Utility window, select your Mac’s startup disk.
   
3. Click the Verify Disk Permissions button. Verify Disk Permissions will take a few minutes.
   
4. Once Verify Disk Permissions has finished running, click the Repair Disk Permissions button. It repairs all disk permissions.
   

You can solve all disk related problems through Drive ToolBox. Volume Repair utility of this tool helps to verify, repair, Rebuild Mac disk permissions. Verify button checks Mac volume for all potential problems whereas Repair button repairs incorrect permissions on Mac OS X and through Rebuild option you can safely perform the 'Verify' and 'Rebuild' operation simultaneously.

Does verify/ repair permissions check the permissions of each and every file on my Mac?

No. Verify/ repair permissions only verifies permissions on files that were placed on your Mac with .pkg installer which has log file to keep track of permissions.