To copy one external hard drive to another on Mac, you have two reliable options: drag and drop files using Finder for a selective copy, or use Disk Utility's Restore function for a full, exact clone. The method you choose depends on whether you need just your documents, photos, and music, or whether you want a bootable, byte-for-byte duplicate of the entire drive.
Copy one external hard drive to another on Mac: your options
Before you begin, connect both external hard drives to your Mac using appropriate cables (Thunderbolt, USB, or USB-C). If they don't appear in Finder, open Finder Settings (or Preferences), select the General tab, and ensure "External disks" is checked, then do the same in the Sidebar tab under Locations. Once both drives are visible, choose your method: Finder for copying individual files and folders, or Disk Utility Restore for a complete clone that erases the destination drive.
Method 1: Drag and drop files using Finder
This is the simplest method for copying data files like documents, photos, and music. It's not recommended for applications, as they may not function correctly when simply copied. To begin, open two Finder windows, one for the source external drive and one for the destination drive.
- Open a Finder window and navigate to your source external hard drive.
- Open a second Finder window and navigate to your destination external hard drive.
- Select the files or folders you want to copy from the source drive.
- Drag them from the source window to the destination window. Alternatively, press Command-C to copy, click inside the destination folder, and press Command-V to paste.
- Wait for the copy to finish. The time depends on the amount of data and drive speed.
This method gives you full control over what gets copied, making it ideal for selective backups or when you want to organize files differently on the new drive. It's also perfect if you want to use a Lacie external hard drive as your new storage destination, just drag your files over and you're done.
Method 2: Clone a whole drive with disk utility restore
WARNING: Using Disk Utility's Restore function will erase all existing data on the destination volume, making it an exact copy of the source. If you have any important data on the destination drive, back it up elsewhere before proceeding. This method is the best choice when you want to upgrade to a larger drive or create a complete backup that includes applications and system files.
- Open Disk Utility, located in Applications > Utilities.
- Choose View > Show All Devices from the menu bar.
- In the sidebar, select the destination volume, the drive that will receive the copy. Double-check this is correct, as it will be erased.
- Click the "Restore" button in the toolbar.
- From the "Restore from" pop-up menu, select the source volume, the drive containing the data you want to copy.
- Click "Restore" to begin the cloning process.
Disk Utility will display a progress bar and an estimated time remaining. During this process, avoid using your Mac for resource-intensive tasks and do not disconnect either drive. The clone will include all files, folders, and the file system structure, creating a bootable copy of your source drive.
What to do after copying completes
Once the copying process finishes, patiently wait for Disk Utility to indicate completion. Then, safely eject the destination external hard drive to avoid data corruption. You can eject it by clicking the eject icon next to the drive's name in Finder's sidebar, or by selecting the drive in Disk Utility and clicking the eject button in the toolbar.
After ejecting, verify the copied data by opening the destination drive in Finder. Randomly select files and folders and open them to confirm they match the original data and are accessible without errors. This verification step ensures the duplication was successful and gives you peace of mind.
Finally, consider the file system format of your destination drive for future use. For full read and write access on a Mac, external drives should be formatted as APFS, Mac OS Extended (Journaled), or exFAT. NTFS formatted drives are typically read-only on macOS, meaning you can copy files from them but not to them without additional software. If you encounter issues moving or copying items, ensure the destination drive has sufficient available space and check or modify permissions for the items or destination location if necessary.
