Scanning as administrator
Sometimes you may not be able to examine certain folders, because you don’t have sufficient access permissions. For example, certain system folders and folders of other local users are normally inaccessible, even when you are logged in to your Mac as an administrator.
In such cases you can scan the target as administrator (also called “as root” or “as super-user”, similar to the command-line tool
sudo. Just select the corresponding command from the disk’s or folder’s drop-down menu
and enter your administrator’s password, when asked.
You don’t always have to scan as administrator. The normal scanning is a little faster, and is enough in most cases. Use the administrator mode when the scan results reveal significant amounts of hidden disk space.
In the latter case, you can significantly save time by selecting the Quick Rescan as Administrator item from the disk’s menu. Holding ⌥ option enables full rescan.
Scanning as administrator only works on local APFS and HFS+ volumes.
If you’re getting an error message while attempting to scan as administrator, check out this article.