How to make a bootable macOS installer on an external drive

In this article, we will follow the necessary steps to create a bootable Mac desktop installer, whether or not to install the latest macOS model on multiple Macs; install the latest macOS beta, perform a clear macOS configuration; or simply to be ready with an emergency unit if your Mac has points and you don’t need to go on the web or in restore mode or in restore mode.

If you need to know how to make a bootable configuration of macOS Catalina, macOS Mojave or an older model of Mac OS X or macOS, you’ve come to the best place.

You can use the bootable installer to install macOS in a separate quantity from your expensive drive (or on a partition, if you are using an older Mac OS model); it is also a hassle-free method to roll back to an older MacOS X or MacOS 1 model. In addition, it is a good option if you find that installing the installer took too long and you do not want to download it multiple times several Macs in the coming days. Once if enough!

Fortunately, making the Mac’s workable system configuration bootable was much simpler when Apple released OS X Mavericks in 2013. With this Mac OS X model and all the variations since then, it was possible to use the Terminal command createinstallmedia to create a bootable macOS installer, we’ll show you how in this article. Before doing this, we would like to obtain the configured data. If you already have them, you can instantly start creating a bootable installer and creating the configuration code to be used.

Read this if you want to run macOS from an external drive, which is completely different.

What do you want to create a bootable configuration unit

There are 2 essential items that you want to configure. The full course does not take long.

A 12 GB flash drive (minimum!)

We advocate a 12 GB (or more) drive, this may be more than you want, the Mojave beta installer was 5.68 GB while the High Sierra installer was 4.3 GB.

We defend a stick reminiscent in Flash, as it is earlier. You also profit from USB 3 or USB Type C – this may be your only alternative when you have a newer Mac.

If you have any data on the disc that you really want to use, you may want to swap it to another disc or buy a new disc, as it will be completely formatted and deleted.

The configured data


Depending on the macOS model you’re using and the model you need to install, you can get the Software Update configuration data in System Preferences on the Mac App Store, otherwise you’ll want to get it from elsewhere.

The Mac App Store may be the best choice; however, there must be points on which macOS model your machine is running on, and if you want to take advantage of the older installation data that can be painful, we’ll show you how to age old variations here can be obtained on macOS.

Obviously, you will want a web connection to download the software program and can use it while placing the macOS model if you want to check the iCloud firmware or credentials.

How to get macOS configuration data

As we said, how you get configuration data depends on the model of macOS you are currently using and the model for which you need the installer. Below, we’ll look at how to get Catalina installers and how to augment old macOS and even Mac OS X variations. We have a specific article on how to download outdated variations of Mac OS X and macOS.

Get Catalina configuration data

Follow these steps to download the installer for the new macOS that arrived in October 2019, macOS Catalina.

  1. If you’re using Mojave on your Mac, go to System Preferences> Software Update.
  2. Wait while your Mac looks for the latest replacement for macOS.
  3. If it indicates that the replacement work system is accessible for download, go ahead and download the configuration data.

However, stop before clicking to install – you want to copy this configuration file before placing it on the Mac, if you want to insert it to create the optimizable installer. Instructions for that below.

How to get Catalina – you must use Catalina

If you already use Catalina, Software Update does not have the software program available for download; however, you can download the configuration data from the Mac App Store.

  1. Open the Mac App Store.
  2. Visit the Catalina web page, you can click this link for Catalina on the Mac App Store.
  3. You should now click Get your Mac to download the installers.

Again, do not click on install, as you will want the configuration file for the next stage of this tutorial…

Get beta configuration data for macOS Catalina

If you are looking for an installer for the Catalina Beta, sign up for the Beta if you want to take a look and check out the new Catalina options before they are released to most people.

Let’s take a look at how to obtain and install the beta version of Catalina here. We have the code where you want to install the Catalina beta via an external drive.

Aging macOS configuration data

With macOS Catalina, Mojave or High Sierra installed, it is a little difficult to get configuration data for older macOS variations. This is when the High Sierra was released, Apple stopped making older variations of the working system available for download on the Mac App Store.

Fortunately, it still can, and we’ll clarify how to get outdated variations of macOS here.

However, if you are not using any of these newer variations of macOS – or have access to a Mac – follow these steps to download configuration data from an older macOS.

See how to get macOS configuration data if you are looking for an older macOS model and are not currently using Catalina, Mojave or High Sierra.

  1. Launch the Mac App Store on your Mac.
  2. Search for the macOS model you need from your reseller (if you previously downloaded the model search below the Purchases tab).
  3. Click the download button. If you have already entered this macOS model, you will see a message that the macOS model is already inserted in this computer. Click Continue to verify that you only need to download the full installer.
  4. Your Mac downloads the installer to the Applications folder. This course may take a while, depending on the pace of your connection and whether or not you are using a wi-fi community. It took us about 10 minutes on Ethernet.
  5. If it starts mechanically after downloading, ceaseyou don’t need to start the configuration course on your Mac as a result, you remove the installers – and these are the installers you want. When it opens, close the installer.
  6. You can find the configuration data in the Applications folder, which you will enter through the Finder.

How to create a bootable macOS installer

Now that you have the data set up, we can move on to creating the bootable installer.

Note that the createinstallmedia technique described here does not work under OS X 10.6 Snow Leopard or earlier – requires OS X 10.7 Lion or later. In addition, the processes have hardly changed since Mavericks. So, if you want to install one of the many “Cat” variations of Mac OS X, it is best to read this older article as an alternative.

Since Mavericks, creating a bootable macOS configuration requires a single command in Terminal. The createinstallmedia command allows you to create a bootable copy of an installer on any drive related to your Mac.

Note that the createinstallmedia command erases all the little things on your external drive, so make sure it doesn’t include what you want.

These are the instructions to follow if you want the macOS High Sierra installer, however, if you want a completely different model from a post-Mavericks or Mojave beta work system, the instructions are likely to be related.

  1. Connect an external drive with a minimum of 8 GB of area (ideally 12 GB), because that’s what the installer wants.
  2. Start Disk Utility (press Cmd + Spacebar and start typing Disk Utility).
  3. Before this subsequent step, remember: if you are using High Sierra or newer, click on the Show drop-down menu below the close reduction buttons. Choose Show all devices from the options. You will now notice the external root unit subsequent to the amount below it.
  4. Select the foundation unit in the sidebar (the following step will not do if you choose only the quantity).
  5. Click Clear.
  6. Choose Mac OS Extended (Daily) because the format.
  7. Choose the GUID partition map as the schema.
  8. Your disc is named Untitled by default, you can identify your disc as “macOS” or “USB”. (Note that it is better to change only the USB period within the Terminal command with the identification of your disk).
  9. Click Clear.
  10. Wait while Disk Uitlity creates the partition and joins the disk (this will take a moment).
  11. Then click Done.
  12. Open the Terminal (the best method is to press cmd + space bar, after which Terminal).
  13. Copy the next textual content corresponding to the macOS model installed in the Terminal. You will find the textual content in the part below.
  14. Click on Enter / Return.
  15. The terminal asks for a password. This is your personal password. Note that you will simply not see any characters appear as you type, which is effective. After entering your password, press Enter.
  16. The Terminal notifies you that it is about to erase the unit (make sure there was nothing essential in it!). To continue, press Y, after which Return. The course may take a while, you will notice “Erase disc: 0%… 10%… 20%… 30%… 100%…

  17. Now, Terminal will spend an instant copying the configuration file to your disk. “Copy installation files to disk … Copy complete” and so on will appear in the Terminal window.
  18. When the Terminal completes the copy of the installer, you will notice the phrases Copy completed and Completed.
  19. You can now have the installer on the external drive that you can use to install multiple copies of macOS. Connect the external drive to the Mac where you need to install macOS.
  20. Boot your Mac and hold down the Option / Alt key during startup.
  21. Your Mac will show the Boot Manager, click on your external drive to select it as the boot disk. Your Mac will start up in restore mode.
  22. Click Install macOS, then click Continue. The macOS model should now be installed on your Mac.

You can run your Mac’s desktop system instantly from an external drive as an alternative to the internal boot disk, which is beneficial when testing new variations of Mac OS. However, the method is completely different from the one described above, and we will cover it here: Learn how to run macOS on an expensive external drive here.

Note that the older macOS variations used the “application path”, while the most recent ones did not. If you use the command, you will receive an error (we have the code for all variations of macOS and Mac OS X below).

createinstallmedia instructions

The createinstallmedia command varies little depending on which macOS model you need to use.

Note MyVolume may have a completely different identification for you, for example, it may be related to USB or something. Check in Disk Utility, it is the identification of the external disk you are using.

Catalina

sudo / Apps / Install macOS Catalina.app/Contents/Resources/createinstallmedia –volume / Volumes / MyVolume

Catalina beta

sudo / Apps / Install macOS Catalina Beta.app/Contents/Resources/createinstallmedia –volume / Volumes / MyVolume –nointeraction –downloadassets

Mojave

sudo / Apps / Install macOS Mojave.app/Contents/Resources/createinstallmedia –volume / Volumes / MyVolume

High Sierra

sudo / Apps / Install macOS High Sierra.app/Contents/Resources/createinstallmedia –volume / Volumes / MyVolume

Saw

sudo / Apps / Install macOS Sierra.app/Contents/Resources/createinstallmedia –volume / Volumes / MyVolume –applicationpath / Apps / Install macOS Sierra.app

The captain

sudo / Apps / Install OS X El Capitan.app/Contents/Resources/createinstallmedia –volume / Volumes / MyVolume –applicationpath / Apps / Install OS X El Capitan.app

Yosemite

sudo / Applications / Install OS X Yosemite.app/Contents/Resources/createinstallmedia –volume / Volumes / MyVolume –applicationpath / Applications / Install OS X Yosemite.app

Mavericks

sudo / Applications / Install OS X Mavericks.app/Contents/Resources/createinstallmedia –volume / Volumes / MyVolume –applicationpath / Applications / Install OS X Mavericks.app