Mac Catalina Boot Usb

2/13/2022by admin

These advanced steps are primarily for system administrators and others who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.

If you have more than one Mac you want to upgrade to macOS 10.15 Catalina but don't want to waste so much bandwidth downloading it for each machine, one option is to create a bootable installer on. A USB 3.0 drive will make things significantly faster, but an older USB 2.0 drive will work in a pinch; 8GB drives worked for Mojave and older versions of macOS, but the Catalina installer is just. Finally, press 'Return' key on the selected option to boot Mac. This way you can boot your Mac with an external USB drive, but the most critical part is to prepare the USB drive. If you have multiple USB drives connected, then the Startup Manager shall list the drives with the bootable OS. So, this is how to boot Mac from USB drive.

What you need to create a bootable installer

  • A USB flash drive or other secondary volume formatted as Mac OS Extended, with at least 14GB of available storage
  • A downloaded installer for macOS Big Sur, Catalina, Mojave, High Sierra, or El Capitan

Download macOS

  • Download: macOS Big Sur, macOS Catalina, macOS Mojave, or macOS High Sierra
    These download to your Applications folder as an app named Install macOS [version name]. If the installer opens after downloading, quit it without continuing installation. To get the correct installer, download from a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. Enterprise administrators, please download from Apple, not a locally hosted software-update server.
  • Download: OS X El Capitan
    This downloads as a disk image named InstallMacOSX.dmg. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder. You will create the bootable installer from this app, not from the disk image or .pkg installer.
Hackintosh

Use the 'createinstallmedia' command in Terminal

  1. Connect the USB flash drive or other volume that you're using for the bootable installer.
  2. Open Terminal, which is in the Utilities folder of your Applications folder.
  3. Type or paste one of the following commands in Terminal. These assume that the installer is in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace MyVolume in these commands with the name of your volume.

Big Sur:*

Catalina:*

Mojave:*

High Sierra:*

El Capitan:

* If your Mac is using macOS Sierra or earlier, include the --applicationpath argument and installer path, similar to the way this is done in the command for El Capitan.


After typing the command:

  1. Press Return to enter the command.
  2. When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
  3. When prompted, type Y to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the volume is erased.
  4. After the volume is erased, you may see an alert that Terminal would like to access files on a removable volume. Click OK to allow the copy to proceed.
  5. When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Big Sur. You can now quit Terminal and eject the volume.

Use the bootable installer

Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:

Apple silicon

Mac Catalina Boot Usb Windows 10

  1. Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
  2. Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes.
  3. Select the volume containing the bootable installer, then click Continue.
  4. When the macOS installer opens, follow the onscreen instructions.

Intel processor

  1. Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
  2. Press and hold the Option (Alt) ⌥ key immediately after turning on or restarting your Mac.
  3. Release the Option key when you see a dark screen showing your bootable volumes.
  4. Select the volume containing the bootable installer. Then click the up arrow or press Return.
    If you can't start up from the bootable installer, make sure that the External Boot setting in Startup Security Utility is set to allow booting from external media.
  5. Choose your language, if prompted.
  6. Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.

Learn more

A bootable installer doesn't download macOS from the internet, but it does require an internet connection to get firmware and other information specific to the Mac model.

For information about the createinstallmedia command and the arguments you can use with it, make sure that the macOS installer is in your Applications folder, then enter the appropriate path in Terminal:

macOS Catalina is a hugely exciting upgrade for the Mac. In some ways, it’s like having a completely new computer. You may have already taken the plunge and installed it, or maybe you’re waiting to see how it settles down before you install it. But whichever camp you’re in, it’s a good idea to create a bootable installer for macOS Catalina. That way, if anything goes badly wrong with your Mac, you’ll be able to boot from the installer and get going again quickly.

Why do I need a bootable installer for macOS Catalina?

There are a number of reasons for creating a bootable USB Mac installer.

  1. If you have more than one Mac, it allows you to install Catalina on all your other Macs without having to download it from the App Store each time.
  2. You may want to clean install Catalina, in which case you’ll completely wipe your startup disk and will need to boot from an external drive to do that.
  3. It’s good protection against a catastrophe striking your Mac’s startup disk, especially if you don’t have a stable internet connection. Normally, if you need to reinstall macOS, you can just boot from the recovery partition and do it from there. However, that means re-downloading the installer. So, if you don’t have an internet connection or it’s very slow, you need an alternative.

What should I use as a bootable installer?

You can use an external hard drive, an SSD or a USB stick. Anything that has at least 16 GB of free space. You’ll need to create a new partition (or container if it’s formatted as AFPS) for the installer so if you have data on it you need, you should copy it to another drive first.

How to create a bootable USB drive for macOS Catalina

Whoa! Not so fast. There’s one more thing you should do before you create the installer: clear out the junk on your Mac. Before you undertake any major task on your Mac, and especially before you install a new version of the operating system, you should clear out junk and old files you no longer need. I don’t normally recommend software tools, but in this case, the nest way to clear out the clutter is to use CleanMyMac X. It can scan your Mac at the press of a button, identify all the files you don’t need, and allow you to get rid of them with one more click. Here’s how to use it:

  1. Install, and launch CleanMyMac X — download a free edition here
  2. Choose Smart Scan from the list of utilities in the sidebar.
  3. Press Scan.
  4. When it’s finished, press Run to delete files immediately, or Review Details to see what it has found.

Once you’ve cleared out the clutter, you can go ahead and create your bootable installer. Here’s how:

  1. Launch the App Store app and search for macOS Catalina. (If you’re reading this before Catalina has been launched, you’ll need to use the public beta. You can sign up for Apple’s public beta program and download it here Apple Beta Software Program)
  2. When the results appear, click on Catalina, then click ‘Get’.
  3. Wait for it to download. When it’s finished, the installer will launch. Quit it immediately.

The installer has now been saved in your Applications folder. You can go ahead and check, if you like. You now have two options for creating the installer. If you’re comfortable with using Terminal, you can go ahead and jump to the instructions for that, below. If you’d rather not use Terminal, there’s a neat utility called Diskmaker X that will do it for you. All you need to do is download and install it and then, when you run it, point it to the macOS Catalina installer you just downloaded. There are full instructions on the download page.

How to create a bootable installer using Terminal

  1. Plug the USB stick, hard drive or SSD into your Mac.
  2. Go to Applications>Utilities and double-click Disk Utility to launch it.
  3. Select the disk you want to use for the installer and choose the Erase tab.
  4. Choose APFS or Mac OS Extended (Journaled) as the format and choose GUID partition map from the options, if it’s available.
  5. Give the disk a name and press Erase.
  6. When it’s finished, quit Disk Utility.
  7. Go to Applications>Utilities and double-click Terminal to launch it.
  8. Type:

    sudo /Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia —volume /Volumes/Untitled

    where ‘Untitled’ is the name of your USB stick or external hard drive

  9. Press Return and wait for the word Done to appear in Terminal.
  10. Quit Terminal

You now have a macOS Catalina installer on an external disk or USB stick. Eject it, unplug it and keep it safe. You can use it to install Catalina on any Mac that supports it.

Mac Catalina Boot Safe Mode

Catalina

One more step: update applications

Once you’ve used tour new installer to install Catalina on a Mac, it’s a good idea to update all your applications so that that are Catalina compatible. You can do this manually, from the App Store and by launching non-App Store apps and choosing check for updates, but that’s a long and tedious process. It’s much quicker and easier to use the updates in CleanMyMac X. Here’s how you do it.

  1. Launch CleanMyMac X.
  2. Select the Updater tool in the Applications section.
  3. Press Select All.
  4. Press Update.

Mac Catalina Boot Usb File

Mac Catalina Boot Usb

Mac Os Catalina Bootable Usb Windows 10

And that’s it. You’re done. CleanMyMac X checks all your installed apps for updates and then updates them all.

Creating a bootable installer for macOS Catalina isn’t difficult. If you have a spare disk or USB stick and are comfortable using Terminal, you can do it right away. If you’d rather not use Terminal, use the Diskmaker X tool described above. Whichever method you use, make sure you use CleanMyMac X to clear out the junk on your Mac before you start, and use it again to update your applications when you’ve finished.

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