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 our guide to using the Recovery HD volume to reinstall or troubleshoot OS X.
Create Your Own Mac Recovery HD on Any Drive
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:
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.
Create a Recovery HD Volume on OS X Lion Through OS X Yosemite
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:
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 the next section. Otherwise, follow the guide to make the Debug menu visible, and then come on back and we'll continue 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 we suggest making 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.
Once you have the destination drive partitioned, we can proceed.
- Launch Disk Utility, located in /Applications/Utilities.
- From the Debug menu, select Show Every Partition.
- The Recovery HD volume will now be displayed in the Device list in Disk Utility.
- In Disk Utility, select the original Recovery HD volume, and then click the Restore tab.
- Drag the Recovery HD volume to the Source field.
- 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.
- When you're sure that everything is correct, click the Restore button.
- Disk Utility will ask if you really want to erase the destination drive. Click Erase.
- You will need to supply an administrator account password. Enter the requested information, and click OK.
- 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).
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.
- Select the new Recovery HD volume from the Device list in Disk Utility.
- 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.
Create a Recovery HD Volume on OS X El Capitan and Later
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.
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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:
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:
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.
- In Terminal, enter the following command, substituting the disk identifier you learned about in the above text:
- An actual example of the command would be:
- If you're using macOS High Sierra or later there is a bug in hduitil command in Terminal that is not recognizing the backslash () for escaping the space character. This can result in the error message 'Only one image can be created at a time.' Instead, use single quotes to escape the entire Recovery HD.dmg name as shown here:
- Hit Enter or Return.
- Terminal will ask for your administrator password. Enter your password, and hit Enter or Return.
- 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.
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, we suggest making the partition size larger than 1.5 GB.
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.
- Launch Disk Utility, if it isn't already open.
- In the Disk Utility window, select the partition you just created. It should be listed in the sidebar.
- Click the Restore button in the toolbar, or select Restore from the Edit menu.
- A sheet will drop down; click the Image button.
- Navigate to the Recovery HD.dmg image file we created earlier. It should be in your Desktop folder.
- Select the Recovery HD.dmg file, and then click Open.
- In Disk Utility on the drop-down sheet, click the Restore button.
- 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, we asked you to use Terminal's 'diskutil' to find the Recovery HD volume. We 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.
- Launch Disk Utility, if it isn't already open.
- 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.
- 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 as we saw earlier.
- With the Recovery HD volume still selected, click the Unmount button in the Disk Utility toolbar.
- Launch Terminal.
- At the Terminal prompt enter:
- Be sure to change the disk identifier to match the one for your Recovery HD volume.
- Hit Enter or Return.
- Provide your administrator password.
- Hit Enter or Return.
That's it. You've created a clone of the Recovery HD volume on the drive of your choice.
Rachel is trying to sell her Mac, but…
My friend was wiping my Mac so I could sell it and I’m pretty sure they’ve deleted the start up disk? It’s not letting me reinstall the OS on a recovery startup.
She wonders about a fix. There are a couple of options with an erased partition.
Because Recovery didn’t work, the fastest way to install fresh is to make or borrow a macOS installer on a USB flash drive or a disk drive. We have instructions for making a bootable installer with macOS Sierra (as well as archived versions for several previous releases). You need at least an 8GB flash drive. The article includes instructions on obtaining the installer, which might involve you having to use someone’s else Mac to download it, if you don’t have a replacement Mac on hand yet.
But if you can’t get access to another Mac or the necessary drive, it’s still possible to use a different Recovery mode on all recent Macs, dating back to 2010. Normally, you can start up a Mac while holding down Command-R to boot into what Apple now calls macOS Recovery. That allows you to run Disk Utility, reinstall or wipe and install the system, access Terminal for command-line functions, and so on. In that mode, when you choose to reinstall without erasing the drive, my recollection is that Recovery looks for the current OS system installer on your startup disk in the Applications folder, and uses that. (Apple doesn’t document that, and I haven’t had to test that for years.)
Failing finding it, Recovery downloads the currently installed version of macOS (or OS X), which is about 5GB. When complete, it installs it and reboots, and places the installer in the Applications folder.
However, there’s yet another option: macOS Recovery over the Internet, which requires either a Mac model released in 2012 or later, or most 2010 and 2011 models with a firmware upgrade applied. There, the Mac reaches out over a Wi-Fi or ethernet connection to download the relatively modest Recovery software, which then bootstraps the download of the full macOS installer.
Apple says Internet-based Recovery should happen automatically on supported models, and you should see a spinning globe when that mode is invoked while the download occurs. However, if you have normal Recovery installed and it refuses to install macOS for some reason, you can manually invoke Internet Recovery.
While Command-R at startup always installs whatever the most recent version you installed on your Mac, holding down Command-Option-R brings down the very latest compatible version that can be installed. Apple also offers Shift-Command-Option-R, which installs the version of OS X or macOS with which your computer shipped, or the next oldest compatible system still available for download.
(Apple just changed this behavior with 10.12.4, but if you’re using Internet Recovery for a clean install on an erased drive, the new behavior should be active as it will be pulled from the version of Recovery that’s bootstrapped from Apple’s servers. The pre-10.12.4 option is simply Command-Option-R, but it acts like the new Shift-Command-Option-R, installing the shipped OS or the oldest compatible version.)
Apple recommends the Command-Option-R option as the only safe way to reinstall a Mac with El Capitan or earlier versions of macOS if you want to be sure your Apple ID doesn’t persist even after erasure.
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