Ask a Macologist
A problem I see pretty commonly is one related to permissions on files that were restored from a Time Machine backup, migrated from another computer, or restored from a deleted User’s home folder that was then migrated to another machine.
Let’s say a customer has restored his data to a new hard drive or new Mac computer from a backup source. These restored files are unavailable due to permissions problems or ownership privileges on the files. The Get Info window cannot solve this issue as the needed options for fixing or changing the permissions are unavailable in Finder. What to do? Fix them in Disk Utility or Terminal!
Disk Utility is a great tool
For solving many permissions errors. It includes two important operations:
• Repair Disk Permissions.
This operation will solve much of the customer’s issues with permissions, but if access problems persist, it might be necessary to change ownership of the files in Terminal.
Using a sudo command
Terminal allows the root user to change the ownership on a single file or recursively to all items in a folder. To do so, first navigate to the location of the file or folders on which you would like to change ownership using the cd command.
If the data is housed on the local User home folder, changing directories won’t be necessary. Then, use the command:
sudo chown -R username:staff /Volume/volumename/username
• where “username” is the short name for the account which you would like to use to access the data
• Volumename is the location of the data on which permissions need repair.
The User will have to authenticate using the User’s admin account password before the action is applied to the file system.
It’s not always the best idea to change permissions in Terminal, but you may need to use it if Disk Utility & Get Info can’t get the job done.