Clone External Hard Drive for FREE to Another External Hard Drive Mac

By Simon Irons / August 30, 2018
Clone External Hard Drive to Another External Hard Drive Mac

Can you Clone an external hard drive to another external hard drive on a Mac, Macbook Pro, Air or iMac? For Free, without paying for cloning software?

Yes you can and I'll show you in this post how.

Who is This Article For?

​The normal everyday user of a Mac.

Someone who is not deeply technical. But is prepared to learn and is happy to be walked through and be shown the steps how.

This post is for someone who needs to clone an external drive onto another external hard drive on a Mac.

What is the Point of Cloning An External Hard Drive?

​And the related question;

How is this different to copying and pasting files, and for that matter drag and dropping files to an external drive?

Copying and pasting, writes files at the file level. It creates a copy of the file yes, but not a copy in its exact location. Plus hidden operating system files and directories won't be copied.

Along with internal links, which may be absolutely necessary for the software you are using. Those links may even be copied but not occupy the place on the drive the software expects.

Copying and pasting is fine for individual files and directories. And a Time Machine back is usually fine for 90 percent of situations.

But there are instances where a Time Machine backup isn't enough. You have entire drive including particular application software and for that software a backup just won't do.

Then you have reached the point of needing a clone copy.

A clone is a block by block copy of one drive onto another, creating a near exact copy.

What Will You Get from this Article?

​I show you how to use a piece of freely available software on your Mac call Disk Utility.

All it takes is a bit of knowledge and an external hard drive to create your clone onto.

Who Is This Method Not For?

​If your particular requirement is to take regular hour by hour or minute by minute clones of a disk drive or cloning across a network or to automate the cloning process, this article is not for you.

For that, think about getting yourself a RAID solution to mirror disks or specialist software.

Because using Disk Utility is straight forward enough but you need to carry out the cloning.

It is a manual process and it is not automated. Disk Utility has no inbuilt scheduling.

Why Clone an External Hard Drive Using Disk Utility


1. Disk Utility is inbuilt into the Mac's operating system so is there freely for you to use.

2. Disk Utility has always been able to be used to create clones. It calls it Restore which is confusing. But once you know ...

3. It is a really good idea to create a clone ahead of any major operating system update.

Because if an update breaks your Mac or a piece of vital software you are using then you can revert back to the previous operating system version from your clone (just go through the process in reverse).

4. You would clone a drive when what you need is an exact copy of that drive.

Say you have an external drive that is partitioned and each partition stores particular files, say your photos on one, movies on another and a third partition as a shared drive between a Mac a PC.

A clone is the perfect answer if you want an exact copy of that external hard drive.

5. Cloning is fast. Faster than taking a Time Machine backup.

How To Clone an External Hard Drive to another External Hard Drive on a Mac

​What you are going to need to know and do

Sounds obvious, but you're going to need

  • the drive you want cloned and
  • a second drive (it doesn't have to be a hard drive it could just as easily be a SSD (a solid state drive)
  • The drives plugged in and connected to your Mac.

Ideally you should see both external drives on your Mac's desktop. You should see these as Icons something like this.

External Drive Icons On Desktop

External Drive Icons On Desktop

​The drive you want to clone onto must be formatted for a Mac. i.e. Mac OS Extended (Journaled) file system (also known as HFS+) with GUID Partition Map scheme chosen on the format page. 

When you format the drive in preparation leave it untitled.

Or give the drive the name No Name, this name will be over written in the cloning process.

Make sure the external hard drive you are cloning onto is at a minimum the same size as your original drive. Preferably a little larger if your original external drive is nearly full.

Remember cloning overwrites everything on the destination drive - the drive being cloned onto. So be happy there is nothing on it that you want or copy it off first elsewhere.

The original drive (the drive to be cloned) and the clone you are creating can't be in use while the cloning is taking place. Disk Utility unmounts the drives for you as part of the process.

And it is probably not a bad idea to refresh your Time Machine backup of your external hard drive. Back up your external drive with your files on ahead of starting the cloning process. Just in case. ​

To Clone the External Hard Drive

​1. Have your Mac powered on and the two drives connected to your Mac.

2. Open up Disk Utility.

You can find Disk Utility from a finder window. It is within your Application folder, inside the Utilities Folder. Or

You can use spotlight search

Spotlight Search Symbol

Spotlight Search Symbol

​Type in Disk Utility

Disk Utility In Spotlight Search

Disk Utility In Spotlight Search

​Click to start up Disk Utility.

3. You should now see all the drives connected to your Mac. They will be listed on the left hand side of the window. The first listed is your internal Mac drive, listed under the Internal heading.

Then the external drives connected to your Mac

Clone Disk Utility StartUp Screen

​In this example we have the drive called W which is our original disk - the drive with all the files on it that we want cloned.

The drive we want to clone onto, the empty drive is called No Name. It is already formatted to Mac OS Extended (Journaled) file system (if you haven't done that already, find out how here).

Select that drive.

Clone Disk Utility Select Drive

​This is important. Be sure you have selected the correct drive, the empty drive, the one you want to clone onto.

4. Then select Restore.

Yes, I know it seems really strange to select the Restore option. But that is what you do.

Clone Disk Utility Select Restore

​5. In the next window select the drive you want to clone. In this case the drive with our files on is called W.

Disk Utlity Choose Clone Drive

​Check and double check, the window helps you with the prompt telling you which drive will be erased and which will be replaced.

6. Select Restore

Clone Disk Utility Confirm Restore

​7. That's it, Disk Utility is away doing the clone, block by block copy. It's reasonably quick and depending on how large the external hard drive is you are cloning it could take a few minutes.

Disk Utility Doing The Restore

You can have yourself a latte till its done.

​Select done when it is completed and you'll see that both your original external hard drive and the cloned external hard drive has the same name and are exact copies of each other.

Clone Disk Utility Done

YouTube Video How to Make A Perfect Clone Disk On Mac OS

​Should you also like to watch a video you can take a look at this 2 minutes 34 second YouTube video to show you how easy it is.

How to Make A Perfect Clone Disk On Mac OS High Sierra/Mac OS Sierra

Video Credit: addictedtomacintosh

Paid Mac Cloning Software

​Here are a couple of the most popular third party software solutions that will allow you to clone your Mac's external hard drive to another external drive.

You would use these when your cloning need is often and perhaps you want to create clones on a schedule.

They also allow you to take backups of external hard drives to another external hard drive and should your requirement mean that you want to backup over a network then you'll need another option to the native software supplied on your Mac.

With both these options you can download and make use of a trial period before you need to go ahead and purchase. That way you can check if the software truly meets your needs and how technical you need to be to use it.

SuperDuper - is sold by a company called Shirt Pocket.

Carbon Copy Cloner - is sold by a company called Bombich Software

Last Words

​And there it is. You now know how to clone an external hard drive to another external hard drive on a Mac for free.

I hope you enjoyed my article and found it helpful.

If after reading you think that what you really want to do is backup using time machine an external hard drive onto another external hard drive then I have an article on the site that tells you how. ​

And if you need is to clone your Mac's internal drive, its boot drive then ​check out this post.

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