Restore a disk using Disk Utility on Mac
You can restore a volume from another volume. When you restore from one volume to another volume, an exact copy of the original is created.
WARNING: When you restore one volume to another, all the files on the destination volume are erased. Before you restore a volume, copy any files on the destination volume that you want to save to a different volume.
Go to the Disk Utility app
on your Mac.If Disk Utility isn’t open, click
in the Dock, type Disk Utility in the Search field, then click .Choose View > Show All Devices.
In the sidebar, select the volume you want to restore, then click
.This is the volume that is erased and becomes the exact copy.
Click the Restore pop-up menu, then choose the volume you want to copy.
Click Restore, then click Done.
You can also use Disk Utility in macOS Recovery to restore a volume. See the Apple Support article If you can’t start up from macOS Recovery.