Select the external disk in the list on the left. Disks appear flush left in the list (volumes are indented below disks). On the right, check if the description below the disk name mentions GUID Partition Map. If it doesn’t, you need to reformat the external disk before you can install macOS on it. Now to install the beta or alternative version of the Mac operating system on your external drive. Open a finder window, go to Applications and find the Catalina or Big Sur installer (or whichever. To start with, as far as I know, an empty drive should/can be Mac OS Extended; Catalina will re-format. Edit: Missed that it is an SSD so APFS is fine. I did that, the only difference being that it was SSD and SSD - Data, instead of Macintosh HD and Macintosh HD - Data. Also, the new OS, Catalina, features Apple Arcade, improved security, and privacy, better accessibility for the disabled, more applications, Find My Mac feature, and many more. However, one problem users tend to face often with new Operating System releases is how to download and install them.
macOS Big Sur is still in pulic beta and not stable according to user feedback. We heard dozens of popular apps like Dropbox and Parallels Desktops not working properly in Big Sur. So it is not the perfect time to upgrade to Big Sur. Instead, you can test it out by installing the OS on an external hard drive or SSD.
Before moving ahead, you must be familiar with the task that you need to perform in the operation. In a glimpse, you will need an external hard drive and format it Disk Utility. Next, you need to download the installer (.dmg file) and then create a bootable USB drive and at last, you will learn the ways to install macOS Big Sur on an external hard drive. Now, you will have to go through each section one by one, and here, you will get the detailed instructions of each method.
Portable Hard Drive or SSD?
The first question comes to the selection of portable external drive, which is the final storage media to keep OS files. It could be a traditional Hard Disk Drive (HDD) or Solid State Drive (SSD). In simple terms, hard drive should be the your choice only if you had tight budget or looked for large volume disk (over 1TB). For rest of the cases, SSD is always the best chocie because of faster writing and reading speed. No one want to run macOS Big Sur on external drive but with weak performance, right?
Please note! No matter what kind of external drive you decided to buy, make sure the ports are compatible with your Mac. On modern Macs, it is usually shipped with USB 3.0 port and Thunderbolt 2/3.
Part 1: Format External Hard Drive or SSD
The default file system on portable hard drive or SSD is exFAT or FAT, which is used for Windows or Linux OS. macOS uses totally different file system so you have to format the external drive first in order to install Big Sur on it. Formatting the external drive (SSD) will wipe all the data associated to it. So, if you had important files, then make sure to take a backup first.
Step 1: Connect the external drive to Mac using the cable.
Step 2: Open Disk Utility and click on the view icon to select Show All Devices.
Step 3: Now, select your connected external drive and further click on the Erase button.
Step 4: You will have to fill the available boxes with the Big Sur or another name in the Name section. Select APFS from the drop-down menu in the format box and finally, select GUID Partition Map for the Scheme section.
Step 5: After completing the above task, click on the Erase button. Now wait for a few seconds as the format process is started and once it is completed, click on the Done button.
Your first task is done as you have formatted the drive to Mac supported format and now you need to download the macOS DMG file for creating macOS USB bootable drive.
Part 2: Download macOS Big Sur DMG File
DMG is the default file type on Mac for compressing files and macOS Big Sur installation file ends with .dmg. If you already got this file, then move to Part 3. If not, please download .dmg file of macOS Big Sur from here (Link 1 & Link 2). The installation file is 10GB so it could take some time to complete the download process. This is largely dependent on how fast your Internet connection is.
Your second task is done and you have successfully download the dmg file of macOS Big Sur. Now, you need software to burn macOS Big Sur dmg file to external drive. This part can be done with the help of UUByte DMG Editor.
Part 3: Create Bootable macOS Big Sur Installer for External Drive
To make a macOS Big Sur bootable drive, you have to burn .dmg file to it. However, this must be done with the right software. A single copy-paste won't work in this way. In here, we will use DMG Editor as example, which can directly write .dmg file to external drive like hard drive, SSD and USB stick. Moreover, DMG Editor allows the users to open and extract the DMG files on both Windows and Mac operating systems.
Step 1: Run UUByte DMG Editor and Connect External Drive
Download and Install UUByte DMG Editor on your Mac and make sure to perform the task from its official site. Plug your external drive to Mac and launch UUByte DMG Editor on your Mac. On the main interface, you will get Burn and Extract options. Click the Burn section, and then click on the Next button.
Step 2: Import .dmg File
Now, import the downloaded file of macOS Big Sur into DMG Editor by clicking on the Browse button. Also ensure that the external drive is detected by this application, if not, then reconnect the drive to Mac.
Step 3: Burn macOS Big Sur .dmg to External Drive
After uploading the OS files, you need to click on the Burn button and within a short time, the burning process will be completed. Once it is done, you will get a successful message on your Mac screen.
The burning process is completed and a bootable drive is ready to use. Now, you need to boot this drive to install macOS Big Sur. The comprehensive steps are provided below.
Part 4: Install macOS Big Sur on an External Hard Drive or SSD
Step 1: Connect the external drive to your Mac.
Step 2: Shut down your Mac and then turn it on. Make sure to press the Option key at booting. Now, select the bootable external drive and then press the Return key.
Step 3: Your Mac will restart few times, and then it will direct you to Recovery Mode; click on the Utilities, and further click on Reinstall macOS.
Step 4: Now, provide the installation path, i.e. your external hard drive, and then click on the Install button. Wait for a while as the installation process will take some time.
Step 5: Once the installation of macOS Big Sur on an external drive is completed, you will be directed to the setup page, and here you need to click on the Continue button.
Step 6: Next, you need to Sign-in with your Apple credentials to sync the files on the iCloud. Now, click on the Get Started button and configure the Big Sur as per your convenience.
Once the setup is completed, you can always boot into macOS Big Sur by pressing Option key at booting stage. This is much more safe and convenient to install macOS on internal drive of your Mac.
Part 5: Troubleshooting Guide
We have tested the whole process throughly on an MacBook Pro and iMac. However, you might experience some error before or after installation process. We have gathered a few common issues according to user feedback and provide useful suggestions to fix it. Please read more and check it out!
Note: macOS Big Sur can be only installed on supported Macs according to Apple Official document. You have to make addition adjustment if you want to install it on unsupported Mac. And you will receive error message more frequently than supported Mac. Please keep this in mind.
Q: External drive is not bootable
A: All Macs with T2 chip will have this issue if Startup Security Utility is enabled on your Mac. This mostly happens on MacBook Pro with Touchbar. Please follow this guide to turn on the options to allow Mac booting from external media.
Q: The Operation couldn't be completed. (BIErrorDomain error 8)
A: Make sure your Mac is connected to Internet. If the error still exists, erase the external drive to HFS+ instead of APFS as we suggested in Part 1. After that, download the latest Big Sur beta and create the bootable installer once more time.
Q: A software update is required to use this startup disk.
A: This error means you just try to install an out-dated version of Big Sur. Please download the latest version and follow the instructions to make a bootable installer.
Q: Installation completed successfully but frozen.
A: Wipe clean the external drive in Disk Utility and create a fresh bootable installer. And repeat the above process. If this does not work and you really want to use macOS Big Sur, please backup your internal drive and install Big Sur on it with a new partition (if the volume is big enough).
So, these were all about the way to install macOS Big Sur on an eternal drive. The method is pretty simple and all you need a bootable USB drive and an external hard drive to accomplish the task. You can simply create a bootable USB drive using DMG Editor because it takes less time and gives the desired output.
An external drive that you can use as an installer for macOS Catalina is a handy thing to have. If you have multple Macs to upgrade, it’s a lot more efficient to plug in the USB installer drive and run the installer than to log into the App Store, download the 8.09GB OS installer, and then run it.
In this article I’ll go over the different ways you can create a bootable macOS Catalina installation drive. But before I give instructions on how to create the drive, I’ll go over the items you’ll need and how to get them.
How to create a bootable macOS Big Sur USB install drive Step 1: Download macOS Big Sur. After Big Sur launches later this year, you’ll be able to download it directly from the Mac App Store.
- When you are troubleshooting and need a fresh installation of the macOS Big Sur, you can use an external drive with a macOS Big Sur installer to get the job done. For you to clean install macOS Big Sur, you need to erase your hard disk first.
- MacOS Big Sur, the major update to the Mac operating system is finally available for download free-of-cost. If you have a Mac running on macOS Catalina, then there are high chances that your.
Get an external drive and maybe an adapter
The macOS Catalina installer software is over 8GB, so you need a USB external drive that can hold that much data. The drive can be a thumb drive, hard drive, or SSD.
If you have a 2015 or newer MacBook or a 2016 or newer MacBook Pro, you may need Apple’s $19 USB to USB-C adapter. This will allow you to connect a storage device that uses a USB type-A connector. If you don’t have an external drive and you have a USB-C Mac laptop, you could buy the SanDisk Ultra USB Type-C Flash Drive, which has a USB-C connector. You can get model number SDCZ450-016G-G46.
When creating the boot drive, the storage device is reformatted, so there’s no need to format the drive beforehand.
Get the macOS Catalina installer software
The macOS Catalina installer is available in the App Store. If you launch the App Store app, do a search for “Catalina.” Or, if you click this Catalina App Store link, it will take you to the Catalina App Store webpage, then click on the “View in the Mac App Store” button.
You can read the information to learn more about Catalina. When you’re ready to download the software, click the Download button. (If you’ve already downloaded the installer, the button will say Install instead of Get.)
Once the download is complete, the installer will launch automatically. But don’t continue with the installation. Instead, press Command-Q on your keyboard to quit the installer.
The Catalina installer app will be in your Applications folder, so you can go there and launch it later to upgrade your Mac to the new operating system.
Make a bootable installer drive: The quick way
I used a free app called Install Disk Creator to make the installation drive. Download Install Disk Creator by clicking on the link. When the download is done, you can move it over to your Applications folder. Then follow these steps to create your bootable macOS Catalina drive.
1. Connect your drive to your Mac.
2. Launch Install Disk Creator.
3. In the main window, you’ll see a pop-up menu under Select the volume to become the installer. Click on the menu and select your drive.
4. Under the pop-up menu, you’ll see Select the OS X installer. (macOS used to be called OS X.) If you have only the Catalina installer on your Mac, Install Disk Creator will automatically select it. If you have other macOS installers, you need to click on Select the OS X installer and select the Catalina installer.
5. When you’re ready, click Create installer. Your Mac may tell you that Install Disk Creator wants to make changes, and you need to enter your user name and password. After you do this, the app will take a few minutes to create the boot drive. A progress bar. appears at the bottom of the Install Disk Create window.
If you try to start the process and you get a failure message saying that the drive couldn’t be unmounted, try reformatting the drive first as ExFAT using Disk Utility. Then start the process over again.
When the app is done, the installer is ready to use.
Install Macos Catalina External Drive Usb
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.
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 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.
Use the 'createinstallmedia' command in Terminal
- Connect the USB flash drive or other volume that you're using for the bootable installer.
- Open Terminal, which is in the Utilities folder of your Applications folder.
- 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
MyVolumein these commands with the name of your volume.
Mac Os Catalina Download
* 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.
Macos Mojave Download
After typing the command:
- Press Return to enter the command.
- When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
- When prompted, type
Yto confirm that you want to erase the volume, then press Return. Terminal shows the progress as the volume is erased.
- 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.
- 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:
Install Macos Catalina External Drive Windows 10
- Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
- Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes and a gear icon labled Options.
- Select the volume containing the bootable installer, then click Continue.
- When the macOS installer opens, follow the onscreen instructions.
- Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
- Press and hold the Option (Alt) ⌥ key immediately after turning on or restarting your Mac.
- Release the Option key when you see a dark screen showing your bootable volumes.
- 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.
- Choose your language, if prompted.
- Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.
For more information about the
createinstallmedia command and the arguments that you can use with it, make sure that the macOS installer is in your Applications folder, then enter the appropriate path in Terminal:
- Big Sur: /Applications/Install macOS Big Sur.app/Contents/Resources/createinstallmedia
- Catalina: /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia
- Mojave: /Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia
- High Sierra: /Applications/Install macOS High Sierra.app/Contents/Resources/createinstallmedia
- El Capitan: /Applications/Install OS X El Capitan.app/Contents/Resources/createinstallmedia
Can I Install Catalina On An External Drive
Mac Os Download
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.