Install Mac Os On External Usb Drive


Oct 01, 2019  Find Main USB Drive. In my case /dev/sda are an internal hard disk of the PC and I am using /dev/sdb is USB Lubuntu Installation media from where this live session is booted. And /dev/sdc is my Main USB drive where I want to install my Linux system and where I have made two partitions in step number 2.If you have skipped step 2, you can also make partitions in this window.

  1. Install Mac Os To An External Drive
  2. Install Macos On External Usb Drive

After successfully created a macOS bootable USB, the next step is how to use it to install macOS from external USB drive. This is not normal case because macOS is very stable and have less bugs/virus than Windows PC. So many Mac users don't know how to perform a clean install of macOS on their Mac when the device was broken or could not boot into desktop.

Please don't worry. We will share detailed steps on how to install macOS/Mac OS X from an USB drive. Even you had issues during this process, it is not thing to be afriad as we have offered the troubleshooting guide as well.

How to Install macOS on Mac from USB Drive (Normal Way)

If the target Mac computer already had a macOS or OS X on it, then installing macOS from USB is straightforward and this is called the normal way.

Step 1: Insert the macOS bootable USB drive on a USB port of Mac computer.

Install Mac Os To An External Drive

Step 2: Shut down the Mac and wait for 1-2 minutes. This will make sure the Mac is powered off.

Step 3: Hold the Power and Option key simultaneously for 15 seconds. This will bring up the Startup Manager on Mac.

Step 4: You will see all bootable devices attached to this Mac, including Macintosh HD and external USB or DVD. Click the drive name of your macOS bootable USB to start the installation process.

Step 5: Agree the terms and conditions and wait for the installation process to be done.

How to Install macOS on Mac from USB Drive (Advanced)

If the drive was not partitioned or the partition table was corrupted, then you can not install macOS on Mac with the normal way. You have to boot Mac into Recovery mode and format the hard drive or SSD to Apple file system first.

Step 1: Shut down your Mac and press the Power key to turn on the Mac; then immediately press Command and R keys.

Step 2: You will be directed to the macOS utility section and here you need to select 'Disk Utility' to format the USB drive. From the Disk Utility app, select Mac drive name under Internal section and then click on the 'Erase' button.

Step 3: You will get a couple of options from the Format. Pleasec choose APFS (macOS) or Mac OS Extended (Journaled) for old version Mac OS X.

Step 4: After the completion of the formatting process, go back to the macOS utility section and this time, select 'Reinstall macOS'.

Step 5: Further, go to the Startup Manager, move to the External drive section, and select your bootable macOS USB drive.

Step 6: Now, the configuration of MacOS will start. As soon as the process starts, it will provide Terms and Agreement page and your job is to agree with the same and then click on the continue button.

Step 7: After that, click on the 'Continue' button to start the installation process. This will take 30-45 minutes and once it gets completed, restart Mac.

Step 8: As you are using the fresh copy of MacOS on Mac machine, so you need to set up the OS and for that connect the Mac with the Wi-Fi and then sign in with the Apple account.

Step 9: After signing in, you can access the several products of Apple such as iCloud, DropBox and many more.

Quick Troubleshooting Tips if You Got Stuck during MacOS Installation

Could not write installation information to disk

If you see the message like 'Could Not Write Installation Information to Disk' when you are trying to install the OS, it means, some important files are missing from the bootable USB device. Mostly, this error happens when you download Mac OS file from an unauthorized site.

You can fix this issue just by downloading the original OS file from the Apple store and then create a fresh bootable USB using the same.

Mac os usb bootable drive. This will bring up the Startup Manager on Mac.Step 4: You will see all bootable devices attached to this Mac, including Macintosh HD and external USB or DVD.

Compatibility error

If you are upgrading the OS X after having an older version, you can get the compatibility error message. In such case, just cross-check the system requirement for the OS you want to install on your Mac system.

You can fix this issue just by downloading the original OS file from the Apple store and then create a fresh bootable USB using the same.

macOS could not be installed on your Computer

If you see the error message similar to 'macOS Could Not Be Installed on Your Computer' that means, either your system is not compatible or the Date and Time settings in your system is not up to date.

To resolve the problem, first, check the system combability for the OS X. If it's fine and still you are facing the error, then just update the system Time & Date with the option of 'Local Apple time server'.

Application is damaged, can't be used to install macOS

You the message 'application is damaged, can't be used to install macOS' appear on your screen, it means the OS certificated has been expired. And so, you won't be able to proceed further for installation.

The simple solution is; you need to create a fresh bootable USB by downloading the MacOS file from its official website.

MacOS couldn't install on this computer

Sometimes, the thirty-party tool which you use to create a bootable USB is the culprit. If the OS files will not be copied successfully using the bootable tool, then you may see the message like 'MacOS couldn't install on this computer'.

In this case, you should avoid using a third party bootable tool despite you should create a bootable USB with the help of command.


The above tutorial covers most of the issues you could come across during the installation process. If you had other issues not mentioned in this article, please contact us and our technical team will help you fix it.

Finally, macOS Catalina 10.15 Public Beta is out and I can’t stay calm! After a bit of work, I was able to install macOS Catalina on an external drive that boots and runs on my Dell 7560 laptop. And in this post, I will show you how to install macOS Catalina 10.15 on an external drive.

Create macOS Catalina Installer Media

Since the macOS Catalina is in first public beta, you don’t want it to be your main OS unless you are a developer. By installing macOS Catalina on an external drive, you can experience the new macOS 10.15 on your system without disrupting the existing macOS High Sierra or Mojave.

If you own a Dell or any other brand laptop powered by 7th gen processors, this guide is for you. The steps are universal for all PC and laptops including Macs. The only thing changes are the files in the EFI partition (not required for Mac). So let us go ahead and begin the macOS Catalina installation on an external drive,

If it’s your first attempt at macOS installation, stop right there. This guide isn’t for you. Read macOS Mojave or High Sierra installation guides. Once you learned the basics and install either Mojave or High Sierra, head to next steps.

If you don’t have a MacBook or Hackintosh, build one. Follow this guide to build a Mojave or High Sierra Hackintosh.

  • Download Beta Utility and run it
  • This will begin downloading macOS Catalina in Mojave systems
  • Download the Catalina update
  • Connect 8GB USB 3.0 drive
  • Open Disk Utility, choose USB drive from the left pane and click ‘Erase
  • Choose Mac OS Extended (Journaled) and GUID Partition Map and click ‘Erase

The USB drive is now ready to become a macOS Catalina Installer.

  • Open new Terminal window and paste the following command. Replace MyVolume with your USB drive volume name
  • Press the Enter key
  • Now download and run EFI Mounter app
  • Select USB disk number and double click to access the EFI partition
  • Download, extract and paste this EFI folder in the ESP partition
  • Edit config.plist if your system isn’t Dell 7560/7460/7X72 series
  • Turn off system

Configure BIOS

  • Turn on the system and access the BIOS by pressing the F2 key as it reboots
  • Disable secure boot
  • Disable PowerShare and VT-D under Virtualization
  • Save and exit

Boot from macOS Catalina Installer Media

  • If you get the boot priority to USB, there’s nothing to do. Just turn on and let it boot.
  • If you haven’t, press F12 continuously as the system starts to access the boot option menu
  • Select the USB media and press the Enter key
  • Now choose Install macOS Catalina from MacOS Catalina Installer
  • Let it boot and load the installer
Install Mac Os On External Usb Drive

Install macOS Catalina on PC or Laptop

  • Agree to the terms and open Disk Utility from above
  • Connect the empty external hard drive or SSD
  • Format the drive to APFS with GUID Partition table. Please make sure it doesn’t contain any data as it will be permanently lost
  • Click ‘Erase’ and then exit Disk Utility
  • Now Select the formatted media and click Install after agreeing upon the Terms and conditions
  • The system will restart one or two times, make sure you select the right drive from Clover bootloader menu to boot macOS Catalina after installation
  • Then you have to set up your system for the first time

Post macOS Catalina Installation Steps

Once you are logged in, check what’s working, and fix what not. I have all the guides on my blog, some need update, but I will update them soon. So use them to fix issues such as Trackpad not working, fix audio/mic, and IntelHD graphics acceleration, etc.

If you are facing error during installation, reach out to me via comments down below. I will respond to each comment and will try to help and resolve the error at the earliest.

Installing macOS Catalina 10.15 or earlier versions isn’t an easy task. Unlike Windows, macOS is hardware specific operating system and does not work with non-Apple hardware. Fortunately, Apple still uses Intel chips in their machines, which enables power users to port the macOS for their Intel-powered Windows machines.


This may sound easy but actually is a cumbersome and time-consuming process. There are several steps involved and it takes several hours, sometimes days, and continuous attempts to install macOS on a PC. Many times, it doesn’t work at all for some.

Install Macos On External Usb Drive

For help, comment down below and I will respond to each query.

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