For more information on backing up your Mac, see How to Back Up your Mac with Time Machine. See also: How to Free Up Storage Space on your Mac Backup your Macīefore you begin, you should make sure you have a recent backup of your Mac.

However, before deleting entire disk volumes, there are several steps you should take to both make sure your data is safe, and to make sure you remove the redundant volume properly. This would indicate that in order to fix this problem, you will want to remove one of these volumes. For example, your two data volumes may have the same size. Now, it appears that, for whatever reason, there is a redundancy. At that time, some users reported having disk volumes like: Starting with macOS Catalina, system files have been separated out into their own disk volume, Macintosh HD, while user data resides in Macintosh HD – Data.Ī similar problem with extra volumes or volumes that couldn’t be unlocked has come up before, when users were upgrading to Catalina. If everything is as it should be, you should see a volume named Macintosh HD and one named Macintosh HD – Data (assuming you haven’t made changes in the past to your disk’s name or structure).

Verify disk could not unmount disk