When you want a simple way clone your Mac’s internal boot drive.
And create a clone Mac boot drive onto an external USB drive.
You’ll find out here the information you need to know.
And you’ll use free software that’s part of your Mac computer.
What’s not to like.
Read on … to find out how.
Overview Of Cloning Your Mac Boot Drive
What you’ll do is;
1. Boot your Mac to MacOS Recovery (Command + r). And sign in.
2. Then use Disk Utility to format your external drive.
3. After that use the Restore in Disk Utility to clone your drive.
What You’re Going To Need To Create Your Clone Drive
1. A USB drive. Either a Mac hard drive (a drive formatted for Mac). Or a SSD (solid state drive formatted for your Mac).
Cloning erases everything on the new drive. And puts on the drive your Mac boot image.
So, if there are files on the drive you’re planning to use. Copy anything you want off first.
2. The drive you want to clone onto – your new, empty drive.
You format to match your Mac’s drive.
The latest Macs have SSD’s inside that are APFS formatted.
Older Mac’s with hard drives inside are Mac OS Extended (Journaled) formatted.
Check the format of your Mac’s drive.
If you don’t know how, then take a quick look at this post. ‘How To Check Format Of External Hard Drive On Mac‘.
Click the link text to go to the post.
3. As Mac’s can come with limited USB ports. You may need a USB hub with the ports you need. Have that ready so you plug in your drive.
To Create Your Mac Boot Clone On Your External Hard Drive The 11 Steps
You can’t use your Mac’s internal drive (the drive you’re cloning). And the clone (the new drive) while you clone.
The beauty of using MacOS Recovery mode and Disk Utility is that it’s easy.
And MacOS Recovery mode unmounts both drives. They aren’t in use and that allows you to create your boot clone.
It’s a good idea to take a Time Machine backup first. Backup your Mac’s drive before you start. Just in case things don’t go quite to plan.
Not sure how? Head over to this article ‘How To Backup Mac To External Hard Drive’.
1. Start With Your Mac Up And Running.
Power on your Mac computer and plug into external power. You don’t want your battery running out part way through.
Plug in your external Mac hard drive. Or external SSD.
2. Reboot Your Mac Into Recovery Mode.
You do this by clicking on the Apple symbol at the top of your desktop screen. And pick Restart or Shutdown. And then start up your Mac.
​3. While Your Mac Boots Up.
Hold down the Command key and the letter r.
You’ll hear a chime. Keep holding the keys for a few more seconds after you see the Apple logo on your screen.
4. Now Wait Till You See The MacOS Recovery Screen.
You may see a screen ahead of MacOS Recovery where your Mac asks you to pick the language you’re using.
Click your language.
And the MacOS Recovery screen will come up next.
​Note
If at any stage before starting the cloning process want to stop. You can.
You do that by moving your cursor to the top of your screen.
Click on the Apple logo.
Pick Shutdown and then you can restart your Mac normally.
Not seeing the Apple logo at the top of the screen?
Move your cursor there anyway and it will come up.
5. Click On The Admin User Name.
Then click Next.
And put in your admin user name password. And click on Continue.
6. Pick Disk Utility From The Menu.
Then click Continue.
Your next window will show you the drives on your Mac. Your MacOS base system is highlighted.
On the left hand side of the window, under the heading Internal. You’ll see your Mac’s drive. Or drives if you’ve more than one. It’s split out into your Mac’s disk image and its data.
Under the heading External. You’ll see listed the drive you plan to clone onto.
7. Click On Your Drive.
Click the on your new, empty drive. The drive you want to clone onto in the external list.
Next pick Erase from the top of the Disk Utilities screen.
8. On The Format Screen.
This is where you set up the formatting of your clone drive.
Depending on the format you want for your Mac’s clone drive. You use the up, down buttons at the end of the format field to pick the format you need.
You choose APFS (Apple File System) if your internal Mac drive is an SSD and formatted as APFS.
Remember you checked on this at the top of this article?
You pick Mac OS Extended (Journaled) from the list if your Mac is an older Mac with a hard drive inside.
Now just double check everything.
That you have your external drive selected. That you’ve picked the right format. And you’ve copied off anything you needed on that drive.
All set?
Then click on the Erase button.
In a few moments you’ve done the formatting of your external drive.
Now it’s formatted click on done.
9. You’re Ready To Clone.
Click on your newly formatted drive. And pick Restore at the top of the Disk Utility Screen. This is what Disk Utility calls the cloning/copying process.
The screen confirms that any data on the drive will be replaced with the data from the selected drive.
And restore should have already picked your Mac’s internal disk image.
You can check on that by clicking on up down buttons at the end of the restore field.
And check it’s Macintosh HD that’s picked.
All set?
10. Click On The Restore Button.
When you’ve clicked Restore. Wait.
As the restore could take a while. Depending on how fast your external drive is. And how much is on your Mac.
When it’s finished. Click Done.
And now you’ve your Mac boot clone.
​11. Restart Your Mac.
You do that by heading to the top of your screen. Click on the Apple logo. And pick shutdown or restart and reboot as normal from your Mac’s internal drive.
To Boot From Your New Mac Clone Boot Drive
1. Booting Your Mac Boot Clone When You Want.
In a non emergency. You can select to boot from your clone drive.
Plug in your drive.
Go into System Preferences.
You can find System Preferences either from your Applications folder. Or use spotlight search (found at the top of your desktop window).
​And type in System Preferences.
​And click to start it up from there.
When you’re in System Preferences click on Startup Disk.
The next screen will show you all your available and connected boot drives.
You’ll see your Mac’s internal drive and the external boot drive you created.
Your internal drive is the drive you are currently booted from and it’s greyed. Your external drive you’ll see in yellow. Click on that and then pick restart.
Then your Mac starts from to your external drive.
If you’ve a lock on your System Preferences to prevent changes. You’ll need to unlock and type in your main password first.
2. Boot Your Mac Boot Clone In An Emergency
When you don’t have access to your internal drive to boot normally.
Plug in your boot drive.
Start up your Mac and hold down the option key.
Your Mac will then show you the start up manager screen.
You can choose the drive you want to boot from there.
Why Clone Your Mac Boot Disk Drive?
1. A clone allows you to have a new drive that is a copy of your Mac’s drive. A drive that you can boot from should the worst happens and your Mac’s internal drive fails.
2. If you plan to replace your internal Mac disk drive. Then cloning your internal startup drive gives you an exact copy. That’s bootable.
You can then replace an older slower Mac drive with a newer, faster hard drive or SSD. Or replace with a new larger drive.
3. You can create a copy of your Mac’s drive ahead of any major operating system update.
Because if the update fails. Or cause problems with your Mac or a piece of crucial software you’re using on your Mac.
You can always revert back from your clone.
Because your clone is an exact copy of your Mac before the upgrade.
Cloning Your Mac Boot Drive FAQ
Q. My Mac’s internal hard drive has failed and I now need to boot from the external drive to carry out repairs.
A. Take a look at the section above titled ‘To Boot From Your New Mac Cloned Boot Drive’. Point 2, that covers in an emergency.
Restarting your Mac while you hold down your Mac’s Option key. Will allow you to choose booting from your external drive.
In Closing
It’s a great idea to have a clone copy of your Mac’s internal hard drive.
– a Mac boot clone drive – just in case your hard drive fails.
You then have the option to get your Mac up and running. With your cloned drive.
Or you need a clone of your Mac’s boot drive so you can upgrade your internal disk to an SSD.
Or larger capacity drive.
While you’re here how about checking out other related articles on the site?
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