Create Your Own Mac Recovery HD on Any Drive

1
Create Your Own Mac Recovery HD on Any Drive

Recovery Disk Assistant
Courtesy of Apple

Ever since OS X Lion, the installation of the Mac OS has included the creation of a Recovery HD volume, hidden away on Mac's startup drive. In an emergency, you can boot to the Recovery HD and use Disk Utility to correct hard drive issues, go online and browse for information about the problems you're having, or reinstall the Mac operating system.

You can discover more about how to use the Recovery HD volume in the guide: Use the Recovery HD Volume to Reinstall or Troubleshoot OS X.

Recovery HD and External Drives

Apple also created a utility called OS X Recovery Disk Assistant that can create a copy of the Recovery HD on any bootable external drive you have connected to your Mac. This is good news for the many Mac users who would like to have the Recovery HD volume on a drive other than the startup volume. However, the utility can only create the Recovery HD volume on an external drive. This leaves out all of the Mac Pro, iMac, and even Mac mini users who may have multiple internal hard drives.

With the help of a few hidden Mac OS features, a little bit of time, and this step-by-step guide, you can create a Recovery HD volume anywhere you like including an internal drive.

Two Methods for Creating the Recovery HD

Due to some changes in features available in the various versions of the Mac OS, there are two different methods to use to create the Recovery HD volume, depending on the version of the Mac OS you're using.

We'll show you both methods; the first is for OS X Lion through OS X Yosemite, and the second is for OS X El Capitan, as well as macOS Sierra and later.

What You Need

In order to create a copy of the Recovery HD volume, you must first have a working Recovery HD volume on your Mac's startup drive, because we're going to use the original Recovery HD as the source for creating a clone of the volume.

If you don't have the Recovery HD volume on your startup drive, then you won't be able to use these instructions. Don't worry, though; instead, you can create a bootable copy of the Mac OS installer, which happens to include all of the same recovery utilities as the Recovery HD volume. You can find instructions for creating a bootable Installer on a USB flash drive here:

Create a Bootable Flash Drive With OS X Lion Installer

Create Bootable Copies of the OS X Mountain Lion Installer

How to Make a Bootable Flash Installer of OS X or macOS (Mavericks through Sierra)

With that out of the way, it's time to turn our attention to what we need to create a clone of the Recovery HD volume.

Creating a Recovery HD volume with OS X Lion through OS X Yosemite starts on page 2.

Creating a Recovery HD volume with OS X El Capitan and later can be found on page 3.

2
Create a Recovery HD Volume on OS X Lion Through OS X Yosemite

The hidden debug menu in Disk Utility
Disk Utility's Debug menu lets you view all partitions, even those that are hidden from the Finder. Screen shot courtesy of Coyote Moon, Inc.

The Recovery HD volume is hidden; it won't show up on the desktop, or in Disk Utility or other cloning applications. In order to clone the Recovery HD, we must first make it visible, so that our cloning application can work with the volume.

With OS X Lion through OS X Yosemite, we can use a hidden feature of Disk Utility. Disk Utility includes a hidden Debug menu that you can use to force hidden partitions to be visible in Disk Utility. This is exactly what we need, so the first step in the cloning process is to turn on the Debug menu. You can find instructions here:

Enable Disk Utility's Debug Menu

Remember, you'll only find the Disk Utility Debug menu available in OS X Lion through OS X Yosemite. If you're using a later version of the Mac OS, jump ahead to page 3. Otherwise, follow the guide to make the Debug menu visible, and then come on back and we'll continue the cloning process.

Creating the Recovery HD Clone

Now that we have the hidden Debug menu in Disk Utility working (see above link), we can proceed with the cloning process.

Prepare the Destination Volume

You can create the Recovery HD clone on any volume listed in Disk Utility, but the cloning process will erase any data on the destination volume. For this reason, it's a good idea to resize and add a partition dedicated to the new Recovery HD volume you are about to create. The Recovery HD partition can be very small; 650 MB is the minimum size, although I would make it slightly larger. Disk Utility probably won't be able to create a partition that small, so just use the smallest size it can create. You'll find instructions for adding and resizing volumes here:

Disk Utility - Add, Delete, and Resize Existing Volumes With Disk Utility

Once you have the destination drive partitioned, we can proceed.

  1. Launch Disk Utility, located in /Applications/Utilities.
  2. From the Debug menu, select Show Every Partition.
  3. The Recovery HD volume will now be displayed in the Device list in Disk Utility.
  4. In Disk Utility, select the original Recovery HD volume, and then click the Restore tab.
  5. Drag the Recovery HD volume to the Source field.
  6. Drag the volume you want to use for the new Recovery HD to the Destination field. Double-check to be sure that you're copying the correct volume to the destination because any volume you drag there will be completely erased by the cloning process.
  7. When you're sure that everything is correct, click the Restore button.
  8. Disk Utility will ask if you really want to erase the destination drive. Click Erase.
  9. You will need to supply an administrator account password. Enter the requested information, and click OK.
  10. The cloning process will begin. Disk Utility will provide a status bar to keep you up to date on the process. Once Disk Utility completes the cloning process, you're ready to use the new Recovery HD (but with any luck, you'll never need to use it).

A few additional notes:

Creating the new recovery HD volume this way doesn't set the visibility flag to hidden. As a result, the Recovery HD volume will appear on your desktop. You can use Disk Utility to unmount the Recovery HD volume if you wish. Here's how.

  1. Select the new Recovery HD volume from the Device list in Disk Utility.
  2. At the top of the Disk Utility window, click the Unmount button.

If you have multiple Recovery HD volumes attached to your Mac, you can select the one to use in an emergency by starting your Mac with the option key held down. This will force your Mac to display all available bootable drives. You can then pick the one you want to use for emergencies.

3
Create a Recovery HD Volume on OS X El Capitan and Later

Terminal displaying results of diskutil list command
The Recovery HD volume's disk identifier is disk1s3 in this example. Screen shot courtesy of Coyote Moon, Inc.

Creating a Recovery HD volume on an internal drive in OS X El Capitan and macOS Sierra and later is a bit more cumbersome. That's because, with the advent of OS X El Capitan, Apple removed the hidden Disk Utility Debug menu. Since Disk Utility can no longer access the hidden Recovery HD partition, we have to use a different method, specifically, Terminal and the command line version of Disk Utility, diskutil.

Use Terminal to Create a Disk Image of the Hidden Recovery HD Volume

Our first step is to create a disk image of the hidden Recovery HD. The disk image does two things for us; it creates a copy of the hidden Recovery HD volume, and it makes it visible, easily accessible from Mac's desktop.

Launch Terminal, located in /Applications/Utilities.

We need to find the disk identifier for the hidden Recovery HD partition. Enter the following at the Terminal prompt:

diskutil list

Hit enter or return.

Terminal will display a list of all partitions your Mac is able to access, including those that are hidden. Look for the entry with the TYPE of Apple_Boot and a NAME of Recovery HD. The line with the Recovery HD item will also have a field labeled Identifier. Here you'll find the actual name used by the system to access the partition. It will likely read something like:

disk1s3

The identifier for your Recovery HD partition may be different, but it will include the word "disk", a number, the letter "s", and another number. Once you know the identifier for the Recovery HD, we can proceed to make the visible disk image.

  1. In Terminal, enter the following command, substituting the disk identifier you learned about in the above text:
    sudo hdiutil create ~/Desktop/Recovery\ HD.dmg –srcdevice /dev/DiskIdentifier
  2. An actual example of the command would be:
    sudo hdiutil create ~/Desktop/Recovery\ HD.dmg -srcdevice /dev/disk1s3
  3. Hit enter or return.
  4. Terminal will ask for your administrator password. Enter your password, and hit enter or return.
  5. Once the Terminal prompt returns, the Recovery HD disk image will have been created on your Mac's desktop.

Use Disk Utility to Create the Recovery HD Partition

The next step is to partition the drive that you wish to have the Recovery HD volume created on. You can use the guide:

Partition a Drive With OS X El Capitan's Disk Utility

This guide will work with OS X El Capitan and later versions of the Mac OS.

The Recovery HD partition you create needs only to be slightly bigger than the Recovery HD partition, which is usually somewhere between 650 MB to 1.5 GB or so. However, since the size can change with each new version of the operating system, I suggest making the partition size larger than 1.5 GB. I actually used 10 GB for mine, quite a bit of overkill, but the drive I made it on has plenty of space.

Once you have partitioned the selected drive, you can continue from here.

Clone the Recovery HD Disk Image to the Partition

The next-to-last step is to clone the Recovery HD disk image to the partition you just created. You can do this in the Disk Utility app using the Restore command.

  1. Launch Disk Utility, if it isn't already open.
  2. In the Disk Utility window, select the partition you just created. It should be listed in the sidebar.
  3. Click the Restore button in the toolbar, or select Restore from the Edit menu.
  4. A sheet will drop down; click the Image button.
  5. Navigate to the Recovery HD.dmg image file we created earlier. It should be in your Desktop folder.
  6. Select the Recovery HD.dmg file, and then click Open.
  7. In Disk Utility on the drop-down sheet, click the Restore button.
  8. Disk Utility will create the clone. When the process is complete, click the Done button.

You now have a Recovery HD volume on the selected drive.

One Last Thing: Hiding the Recovery HD Volume

If you remember back to when we started this process, I asked you to use Terminal's diskutil to find the Recovery HD volume. I mentioned it would have a type of Apple_Boot. The Recovery HD volume you just created isn't currently set to be an Apple_Boot type. So, our last task is to set the Type. This will also cause the Recovery HD volume to become hidden.

We need to discover the disk identifier for the Recovery HD volume you just created. Because this volume is currently mounted on your Mac, we can use Disk Utility to find the identifier.

  1. Launch Disk Utility, if it isn't already open.
  2. From the sidebar, select the Recovery HD volume you just created. It should be the only one in the sidebar, since only visible devices show up in the sidebar, and the original Recovery HD volume is still hidden.
  3. In the table in the right-hand pane you'll see an entry labeled Device:. Make a note of the identifier name. It will be in a format similar to disk1s3 like we saw earlier.
  4. With the Recovery HD volume still selected, click the Unmount button in the Disk Utility toolbar.
  5. Launch Terminal.
  6. At the Terminal prompt enter:
    sudo asr adjust --target /dev/disk1s3 -settype Apple_Boot
  7. Be sure to change the disk identifier to match the one for your Recovery HD volume.
  8. Hit enter or return.
  9. Provide your administrator password.
  10. Hit enter or return.

That's it. You've created a clone of the Recovery HD volume on the drive of your choice.