How to Clone Mac Hard Drive to an External HDD or SSD

You have enough good reasons to clone your Mac hard drive, for example,

• Creating a comprehensive backup of your Mac including system, apps, files, and settings in case of device damage or data loss
• Skipping the time-consuming setup process when transitioning to a new Mac
• Replicating the same system environment for employees, software testing, or other purposes

This guide will show you how to clone your Mac's hard drive to an external drive, using either Mac's native tools or third-party cloning software for Mac. This guide works for both Mac computers equipped with Intel and Apple silicon chips. 

Before Cloning Your Mac Hard Drive

Before diving into the step-by-step instructions for cloning your Mac's hard drive, there are some preparations you need to make to ensure a smooth and successful disk clone.

1. Back up your Mac

This is a common tip before you perform any tasks on your Mac. While the cloning process itself is unlikely to cause harm to your data or system, unforeseen events such as system crashes, app failures, or power outages could potentially lead to data loss or file corruption. 

To ensure peace of mind, it's advisable to back up your Mac using Time Machine or create a copy of your most important data on an external storage device.

2. Keep your Mac clean

Disk cloning involves duplicating everything from your Mac's hard drive to another storage location. The time it takes for this process varies depending on the amount of data to be cloned. It is best to thoroughly clean up unnecessary files and redundant data to minimize the time required for the cloning operation.

BuhoCleaner stands out as the top tool to ensure a smooth and fast Mac hard drive cloning experience.

Key features of BuhoCleaner:

• Quickly find and clean junk files on Mac
• Uninstall unused apps and app leftovers in one click
• Identify and remove large files from Mac hard drive
• Delete duplicate photos, files, and folders in seconds
• Free up RAM to boot Mac's processing power for faster cloning

3. Prepare Your External Hard Drive

Whether you're cloning your Mac hard drive to a traditional hard disk drive or a solid-state drive, you'll need to prepare the disk to ensure it's ready to store the clone.

Here is how:

Step 1. Make sure the external drive has equal to or larger capacity than the hard drive in your Mac.

Step 2. Connect the external disk to your Mac via the appropriate USB port. 

Step 3. Open Finder > Applications > Utilities > Disk Utility.

Step 4. Select the external hard drive from the sidebar and click the Erase tab at the top.

Step 5. Name the drive, select macOS Extended (Journaled) from the format list, and choose GUID as the scheme.

Step 6. Click Erase. 

Step 7. Click Done when the process is complete and close the Disk Utility window.

How to Clone Mac Hard Drive - For Intel-based Macs 

Now it's time to begin cloning the hard drive on your Mac to another disk. The process is straightforward using a Mac's built-in utility, especially if your Mac is equipped with an Intel processor.

How to clone your Mac hard drive using Disk Utility

Step 1. Open the Disk Utility app on your Mac. You have several ways to open it:

• Navigate through Finder > Applications > Utilities and double-click on Disk Utility
• Open Launchpad on the Dock, open Others, and click on Disk Utility
• Press the Command + Space bar together on your keyboard to launch Spotlight search, type in Disk Utility, and click on the app when it appears in the results

Step 2. Select the backup drive you want to clone your Mac hard drive to as the target drive, and then click Restore at the top.

Step 3. In Disk Utility, a drop-down window will appear. From the Restore from menu, select your Mac SSD, typically labeled as APPLE SSD XXX, as the source drive.

Step 4. Click Restore to begin the cloning process.

Step 5. Disk Utility will display a progress bar, gradually filling up as it clones your drive. Once finished, simply click Done.

How to Create a Clone of Your Mac - For Apple Silicon Macs 

Cloning a Mac hard drive on an Apple Silicon Mac is more complex. Copying the operating system to an external device is particularly challenging on a Mac with an Apple Silicon chip.

That's because starting in macOS Big Sur, the system resides on a cryptographically sealed "Signed System Volume" that can only be copied by an Apple-proprietary utility. This means that most third-party Mac cloning tools and even the built-in Disk Utility can't duplicate the operating system on the Mac hard drive. Consequently, the clone you create likely only contains the Data volume, which stores your documents, applications, and system settings that are outside of the system data. This type of clone is not bootable.

Luckily, there still is hope. SuperDuper! claims it can create a full bootable backup of your Mac running macOS Big Sur and later and the backups are completely Apple silicon native. Additionally, plenty of other workarounds are available for transferring data between two Macs, such as using Time Machine, Disk Image, and an APFS snapshot.

Let's take a look at how to use SuperDuper to create a bootable clone of an Apple silicon Mac.

How to clone Mac hard drive to SSD on Mac with Apple silicon

Step 1. Download the latest version of SuperDuper! on your Mac and follow the prompts to install it.

Step 2. Launch SuperDuper! and connect your target SSD to your Mac via a USB port.

Step 3. Set up the SuperDuper! to copy from Macintosh HD to your external SSD using the backup - all files method.

Step 4. Click Copy Now to initiate the cloning process. 

How to Restore Your Mac from a Clone

Now that you have a clone of your Mac hard disk on an external drive. If you need to restore your Mac from this clone in case of data loss or system malfunctions, follow the instructions below. 

Restoring an Intel Mac from a clone on an external hard drive

Step 1. Turn off your Mac and connect the external hard drive to your Mac.

Step 2. Press the power button to turn on your computer and hold down the Command + R keys as soon as the system restarts.

Step 3. If you see the macOS Utilities window, your Mac successfully enters the macOS Recovery Mode. Click on Disk Utility and Continue.

Step 4. Select the Mac hard drive and click on the Restore tab at the top.

Step 5. Select your external drive next to Restore From.

Step 6. Select your Mac's hard drive next to Restore and click Restore.

Step 7. Restart your Mac once the backup restoration is completed.

Restoring an Apple silicon Mac from a clone on an external hard drive

Step 1. Open the SuperDuper! application on your Mac and connect the backup drive to your Mac.

Step 2. Select the backup disk from the Copy menu, and select the Mac's hard drive from the To menu.

Step 3. From the Using menu, select Restore - all files. 

Step 4. Click Copy Now and wait until the restoring process completes. 

How to Boot Your Disk Clone on Another Mac 

Now you possess a bootable version of your Mac's hard drive cloned from a previous device, you can use the following steps to use it as a Mac startup disk and transfer data to another Mac. 

How to boot your clone on another Intel Mac

Booting your clone on an Intel-based Mac without a T2 chip:

Step 1. Connect the external drive where the disk clone is saved to your Mac.

Step 2. Turn on the new Mac you want to boot from the clone and press and hold the Option keys immediately.

Step 3. Use the arrows to highlight the external boot drive.

Step 4. Press Return to let your Mac boot from it.

Booting your clone on an Intel-based Mac with T2 chip:

Step 1. Turn on your Mac, then press and hold Command + R immediately to enter macOS Recovery Mode. 

Step 2. When you see the macOS Utilities window, choose Utilities > Startup Security Utility from the menu bar.

Step 3. In the Startup Security Utility window, reset the Secure Boot to Medium Security; under Allowed Boot Media, check Allow booting from external or removable media.

Step 4. Authenticate the change with your admin password and turn off your Mac.

Step 5. Connect the external drive where the disk clone is saved to your Mac.

Step 6. Turn on your Mac with the Option key pressed.

Step 7. Select the external clone hard drive and run it for booting. 

How to boot your clone on another Apple Silicon Mac

Step 1. Connect the external drive where the disk clone is saved to your Mac.

Step 2. Turn off your Mac and press and hold the power button until Loading startup options appears.

Step 3. When you see the available startup disks, select the clone boot drive.

Step 4. Click Continue and your Mac will restart from the disk you selected.

Conclusion

Cloning your Mac allows for a complete duplication of your computer, which can then be utilized for Mac restoration or setting up a new Mac. This post guides you through the entire process, covering preparation steps, how to clone your Mac hard drive using Disk Utility, how to clone your Mac hard drive to SSD on an M-series Mac, how to restore a Mac from a clone, and how to boot a clone.   Before diving in, streamline the process by using BuhoCleaner to remove junk data and unwanted files. Download now for free.