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.
In the Disk Utility app on your Mac, choose View > Show All Devices.
If Disk Utility isn’t open, click the Launchpad icon in the Dock, type Disk Utility in the Search field, then click the Disk Utility icon .
In the sidebar, select the volume you want to restore, then click the Restore button .
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 About macOS Recovery.