Changing Read and write permissions for mac Hard drives

In an effort to improve security and prevent corruption of system files, macOS separates Macintosh HD into two volumes, one for user data and the other for system files, the latter being read only by default. This, however, is designed to be transparent to the user and thus shouldn't cause you to have permissions issues.

One thing you could try, especially if the account was migrated, is to create a new user account and see if the issues persist. If they don't and macOS works as you'd expect on the new account, the old one has likely become corrupted. To delete the old account while preserving your files:

1. Open System Preferences > Users & Groups, hit the "Click the lock to make changes" button and enter your password.
2. Select the old account in the "Users, groups and login options" list, and click delete user or group.
3. In the dialog that appears, select the "Keep the home folder" radio button and click delete.
4. Click add user or group, and give it the same name as your old account and home folder. After you click create, macOS should show a dialog that asks you if you want to use the folder that already exists as the new account's home folder; choose to do that and the new account should be created with all your data intact.

If that doesn't work, you may want to try reinstalling macOS, as that may resolve common problems caused by migration.

HTH

You are signed in a system administrator, right? Doublecheck to see which user profile you're using and confirm you have rights to change permissions. Your difficulties might have something to do with the rights associated with the user you are signed in as.

Just a thought. Smile. I get them from time to time.

macOS requires at least one account to be an administrator, so if yours is the only one on the computer, it should be an administrator account. You can check by interacting with your name in the "Users, groups and login options" list, and pressing VO-Right-Arrow once. It should say either admin or standard, so if it says admin, you're signed into an account with full administrator privileges.

Also, regarding deleting a user account, you must first create a new one before the "Delete user or group" button will become available.

HTH

I admittedly haven't done this process in a while, but from what I remember and understand about macOS's behavior, you should be able to create a new temporary user account that has any name besides the name of your existing account. Then, after logging into the temporary account, you should be able to delete the old one but opt to preserve the home folder in place, and then create a new account with the same name as your old account and home folder; macOS should then offer to associate your home folder with the new account.

HTH

Are you trying to change permitions on mac hd or mac hd data? If its on hd hthat volume is read only, as it only has files related to the OS.