Create Mac Os Bootable Usb Drive

By default, Mac starts from its built-in hard disk, but a startup disk can be any storage device that contains bootable contents that compatible with your Mac. For example, if you install macOS or Microsoft Windows on a USB drive, your Mac can recognize that drive as a startup disk. This guide provides 2 ways to boot a Mac from a USB flash drive.

Requirement

Plug the external drive into the Mac that you want to install the macOS on. Start up the Mac, holding down the Option/Alt key while it is booting up. Your Mac will display the Startup Manager.

How To Create A Mac Os Bootable Usb Drive

Starting up your Mac from an external disk requires the following:

• Intel-based Mac.
• Bootable USB thumb drive formatted with a GUID partition type and containing an OS X installer or a usable operating system.

Apr 10, 2020  Fortunately, there's a great tool that you can use for free to create bootable macOS media on a USB drive in a Windows 10 environment. This article shows you how to download a macOS DMG file, format a USB drive using a GUID Partition Table, burn the DMG to the drive and boot your Mac from the USB. The easiest way to create a USB flash installer is with the free program, Disk Creator. Download the macOS Sierra installer and Disk Creator. Insert an 8GB (or larger) flash drive. If you have any. USB Stick / External Hard Drive: If you are planning to use a USB for downloading the bootable version of the installer, make sure that it is 8GB in size or larger than that. In the case of Sierra, 12GB is recommended as the minimum requirement.

Let’s see how to boot a Mac from a bootable USB drive and what to do if your Mac doesn’t start up from it.

Way 1: Boot Mac from USB Drive using Startup Manager

Getting your Mac to load from a USB drive is fairly straightforward. Use the following steps, you can easily set Mac boot from an external drive in Startup Manager, so it’ll only boot from USB that one time.

Step 1: Insert the USB boot media into a USB slot.

Step 2: Turn on your Mac (or Restart your Mac if it’s already on).

Step 3: Press and hold the Option key immediately after you see the Apple logo. Holding that key gives you access to OS X’s Startup Manager. Once the Startup Manager screen appears, release the Option key. The utility will look for any available drives that include bootable content.

Step 4: Using either the pointer or arrow keys on the keyboard, select the USB drive you wish to boot from. Once selected, either hit the Return key or double-click your selection. The machine will start to boot from the USB drive.

Way 2: Set a Mac Boot from USB Drive using Startup Disk

When you use Startup Disk preferences to set Mac boot from an external drive, so it’ll boot from that disk until you choose a different one. Here is how:

Step 1: Go to Apple menu > System Preference, then click Startup Disk.

Step 2: Click the locked icon and then enter your administrator password.

Step 3: Select External drive as the startup disk, then restart your Mac.

What to do if your Mac does not boot from the selected drive

If you see a message prompts that your security settings do not allow this Mac to use an external startup disk, check the External Boot setting in Startup Security Utility, and then allow your Mac to use an external startup disk.

Step 1: Open Startup Security Utility.

Turn on your Mac, then press and hold Command (⌘) + R immediately after you see the Apple logo. Your Mac starts up from macOS Recovery. When you see the macOS utility window, choose Utilities > Startup Security Utility from the menu bar. When you’re asked to authenticate, click Enter macOS Password, then choose an administrator account and enter its password.

Step 2: Select “Allow booting from external media“.

If you want to select an external startup disk before restarting your Mac, quit Startup Security Utility, then choose Apple menu > Startup Disk.

Note: If you’re using Boot Camp in a dual-boot Windows/OS X environment, you may be unable to boot negatively into supported versions of Microsoft Windows XP, Windows Vista or Windows 10 operating systems installed on external USB hard drive.

Make sure disk has been formatted with a GUID partition type

Intel-based Macs support starting from an external USB storage device’s volume that has been formatted with a GUID partition type. If you wish to boot from the drive, it’s important to format the partition as “GUID Partition Table” rather than either of the other two ahead of time when you use that drive as a bootable drive.

Make sure your disk is bootable

Volumes that aren’t bootable and don’t contain a copy of a valid operating system aren’t listed in Startup Disk or Startup Manager. Make sure the external drive you’re trying to start from contains a usable operating system.

Jul 10, 2020 • Filed to: Solve Mac Problems • Proven solutions

Creating a bootable drive for your Mac certainly seems to be a wise decision to make. Even though MacOS recovery partition can take care of all your recovery requirements in times of need, it’s still worthwhile to have a bootable installer.

Why Do You Need to Create A Bootable Drive For Your Mac?

• The Mac installer gets deleted as soon as you download it and use it by installing the Mac operating system. Once the installer gets deleted, it means that you can no longer use it to install the MacOS on another Mac device. You will have to again download the installer on the latter Mac to install the MacOS. This can take a lot of time and become inefficient if you have multiple Macs.
• Clean installs can be performed by installers which are very helpful in overwriting your start-up drive. You can also use this function for other troubleshooting issues as well.
• When you have a bootable installer, it ensures that you are well guarded in an emergency scenario by making use of some of its helpful utilities.
• A bootable installer can allow you to install an earlier version of MacOS and also let you temporarily boot into the previous version of the MacOS.

What Do You Need Before Creating Your Bootable Drive?

Before you begin the process, you will need the following:

• USB Stick / External Hard Drive: If you are planning to use a USB for downloading the bootable version of the installer, make sure that it is 8GB in size or larger than that. In the case of Sierra, 12GB is recommended as the minimum requirement. Ideally, 32GB to 64GB is a good size to have as it is not only cost-effective but also gives a better performance. In the case of an external drive, you can use any spare one that you are not going to use for any other work.
• Download MacOS High Sierra Installer: It is important to note that once you have downloaded the installer, it will begin with the installation process on its own. You can close the installer just like you quit any Mac app. In the case of the macOS version being older than the current one, you can click on ‘ok’ once the message flashes that the version is too old to install. You can find the old installer file in your ‘Application Folder’. Don’t forget to take a backup of your Mac to be on a safe side.

Part 1. How to Create a Bootable Drive Using Terminal

There are two ways of creating a bootable copy of the installer. You can either use Terminal or get the job done through a free software like Recoverit to do it for you. First, let us look at how to create a bootable drive using Terminal.

Steps to create a MacOS Siera beta boot disk:

1. The first step in the process is to connect your external hard drive to your Mac. You need to name your external drive ‘untitled’ for the Terminal command to work.
2. Launch Terminal. You can find this in the 'Utilities' folder of your Applications folder.
3. Copy the following instructions now:
sudo /Applications/Install macOS Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install macOS Sierra.app
4. In this step, you have to paste the copied instruction on the screen by going back to the Terminal.
5. You will be required to feed in your user password now and then hit ‘Return’.
6. Now, the Terminal will ask for your permission to erase the drive. To continue, type ‘Y’ and again hit return.
7. After the Terminal has erased your drive, your Mac will prompt you if you wish to use the drive for Time Machine. Click ‘Don’t Use’.
8. Next, the installer file will be copied by the Terminal to your drive. This might take some time, so be patient.
9. Once the copying is completed, a ‘Copy complete’ message will be displayed on your screen. You can now quit the Terminal and use your drive.

Part 2. How to Create Bootable Media for Mac with Recoverit Mac Data Recovery

Recoverit Mac data recovery software is one of the most impressive and easy-to-use data recovery software in the market, and it has lots to offer with its varied utilities and functions. With Recoverit to create bootable media, you can access your system easily without the need to reinstall the MacOS to recover your lost data.

Step 1 Launch Recoverit and get to select 'Computer Crash Recovery'. Click 'Start'.

Step 2 Choose your connected external hard drive as the bootable media, and click 'Start'. You will receive a requirement of formatting the device. Before the formatting, remember to back your drive data up.

Step 3 Wait for a while, and Recoverit will format your drive and start creating the bootable media.

Step 4 Once it finishes, follow the next steps to restore data back.

Part 3. How to Set the Computer Boot from the Bootable Media

Create Bootable Mac Os Usb On Windows

Step 1 Connect your external drive to your unbootable Mac.

Step 2 Press down on the ‘Option’ key after restarting your Mac.

Step 3 Once the booting has finished, your Mac will display the Startup Manager to show you the available boot drives. Select your external hard drive and hit ‘Return’.

Step 4 If you want to install Sierra but keep your data untouched, you can select 'Install OS X'. However, if you wish to delete all your data, then you can select Disk Utility to format the entire drive and wipe away all your data to reformat the internal drive first and then install MacOS Sierra.

You now have a bootable copy of the MacOS Sierra installer, and you can use it on multiple Macs to install the Mac OS. If you are familiar with the command line, you can opt to create a bootable drive using Terminal. For others, you can simply opt for reliable Mac hard drive recovery software like Recoverit and assist you in recovering your data as well from crashed systems in case of emergencies.

What's Wrong with Mac

Recover Your Mac

Fix Your Mac

Delete Your Mac

Learn Mac Hacks