Are you tired of running out of storage space on your Mac? Or maybe you want to try out a different version of macOS without committing to a full installation? Running macOS from an external hard drive can be a great solution. But can you really do it? In this article, we’ll explore the possibilities and limitations of running macOS from an external hard drive.
What is an External Boot Drive?
Before we dive into the details, let’s clarify what an external boot drive is. An external boot drive is a separate hard drive or solid-state drive (SSD) that contains a bootable operating system, in this case, macOS. This drive is connected to your Mac via a cable or wirelessly and allows you to boot from it instead of your internal hard drive.
The Benefits of Running macOS from an External Hard Drive
Running macOS from an external hard drive offers several advantages:
Increased Storage Space
If you’re running low on storage space on your internal hard drive, an external boot drive can provide additional storage for your files, apps, and data. This is especially useful for creatives who work with large files or for those who have extensive music and video libraries.
Test New macOS Versions
Want to try out the latest version of macOS without committing to a full installation? An external boot drive allows you to test new versions without affecting your current setup.
Boot Multiple macOS Versions
You can create multiple partitions on your external hard drive, each with a different version of macOS. This is useful for developers, testers, or anyone who needs to work with different macOS versions.
Mac Recovery and Troubleshooting
An external boot drive can serve as a backup in case your internal hard drive fails or becomes corrupted. You can boot from the external drive to recover your data or troubleshoot issues.
Requirements for Running macOS from an External Hard Drive
To run macOS from an external hard drive, you’ll need:
A Compatible Mac
Not all Macs are compatible with external boot drives. You’ll need a Mac that supports Target Display Mode (TDM) or has a Thunderbolt 3 (USB-C) port. Check Apple’s support page to see if your Mac is compatible.
A Compatible External Hard Drive
Your external hard drive must meet certain requirements:
- It must be a formatted HFS+ or APFS drive.
- It must be connected via a compatible cable or wirelessly via Thunderbolt 3 or FireWire.
- It must have enough storage space to hold the macOS installation and any additional files or apps.
A macOS Installation
You’ll need a legitimate copy of macOS to install on your external hard drive. You can use the macOS installer from the App Store or create a bootable installer using Apple’s macOS installer tool.
The Steps to Run macOS from an External Hard Drive
Now that you have the requirements, let’s walk through the steps to create an external boot drive:
Step 1: Prepare Your External Hard Drive
Connect your external hard drive to your Mac and format it using Disk Utility. Make sure to select the correct file system (HFS+ or APFS) and partition scheme.
Step 2: Create a Bootable Installer
Download the macOS installer from the App Store or create a bootable installer using Apple’s tool. Follow the instructions to create a bootable USB drive or external hard drive.
Step 3: Install macOS on the External Hard Drive
Insert the bootable installer and restart your Mac. Hold the Option (⌥) key while booting to access the Startup Manager. Select the external hard drive as the boot device and follow the installation process.
Step 4: Set Up Your External Boot Drive
Once the installation is complete, set up your external boot drive as you would a new Mac. Create a user account, set up Wi-Fi, and install any necessary apps or files.
Troubleshooting Common Issues
You may encounter some issues when running macOS from an external hard drive. Here are some common problems and solutions:
Slow Performance
If your external hard drive is slow, consider upgrading to a faster drive or using a solid-state drive (SSD). You can also try optimizing your drive for better performance.
Compatibility Issues
If your external hard drive isn’t compatible with your Mac or macOS version, try using a different drive or adapter.
Boot Issues
If your Mac won’t boot from the external hard drive, try restarting your Mac and holding the Option (⌥) key while booting. Select the external hard drive as the boot device and try again.
Conclusion
Running macOS from an external hard drive can be a convenient and flexible solution for those who need additional storage space, want to test new macOS versions, or require a backup boot drive. While there are some requirements and potential issues to consider, the benefits of an external boot drive make it a viable option for many Mac users. By following the steps outlined in this article, you can create your own external boot drive and enjoy the advantages it has to offer.
What are the benefits of running macOS from an external hard drive?
Running macOS from an external hard drive provides several benefits, including increased flexibility, improved performance, and enhanced data security. By booting your Mac from an external drive, you can easily switch between different operating systems, try out new software or configurations without affecting your main system, and even use the same drive on multiple Macs.
Additionally, running macOS from an external hard drive can also help to free up space on your internal drive, reduce clutter, and make it easier to manage your files and data. Plus, if your internal drive fails or becomes corrupted, you can simply boot from the external drive and access your files and data as if nothing had happened.
What kind of external hard drive do I need to run macOS?
To run macOS from an external hard drive, you’ll need a drive that meets certain specifications. First, the drive must be able to support the Mac’s boot process, which means it needs to be compatible with the Mac’s firmware. Additionally, the drive must have a high enough storage capacity to hold the macOS operating system and your files and data.
In terms of specific requirements, a fast SSD (solid-state drive) with a high read and write speed is recommended. A USB-C or Thunderbolt 3 connection is also preferred, as these connections provide faster data transfer speeds. Some popular options include the Samsung X5, the SanDisk Extreme Pro, and the OWC ThunderBay 4.
How do I prepare my external hard drive for macOS?
Before you can run macOS from an external hard drive, you’ll need to prepare the drive by formatting it and installing the operating system. To do this, you’ll need to connect the drive to your Mac, open the Disk Utility app, and select the drive as the target disk. Then, you’ll need to erase the drive, create a new partition, and install macOS onto the drive.
It’s also a good idea to clone your current startup drive to the external drive, which will ensure that all of your files, settings, and applications are transferred over. You can use a cloning app like SuperDuper! or Carbon Copy Cloner to do this. Additionally, you may want to consider creating a bootable installer for macOS on the external drive, which will allow you to easily reinstall the operating system if needed.
How do I boot my Mac from an external hard drive?
To boot your Mac from an external hard drive, you’ll need to connect the drive to your Mac and restart your computer. As the Mac boots up, hold down the Option (or Alt) key to access the Startup Manager. From there, select the external hard drive as the boot disk, and the Mac will boot from the drive instead of the internal drive.
If you’re using a newer Mac with a T2 chip, you may need to hold down the Power button and the Volume Down button at the same time to access the Startup Manager. Additionally, you may need to go into the Startup Security Utility to allow booting from an external drive. This can usually be found in the Utilities window during the boot process.
Can I use an external hard drive as my main startup drive?
Yes, you can use an external hard drive as your main startup drive, but it’s generally not recommended. First, external drives are often slower than internal drives, which can result in slower performance and longer startup times. Additionally, external drives are more prone to damage or loss, which could result in data loss or corruption.
That being said, if you do decide to use an external hard drive as your main startup drive, make sure to choose a high-quality drive with fast read and write speeds, and consider using a ruggedized or waterproof enclosure to protect the drive. It’s also a good idea to keep a backup of your data and operating system in case the drive fails or becomes corrupted.
How do I switch between my internal and external hard drives?
Switching between your internal and external hard drives is relatively easy. To switch to the internal drive, simply restart your Mac and hold down the Option (or Alt) key to access the Startup Manager. From there, select the internal drive as the boot disk, and the Mac will boot from the internal drive instead of the external drive.
To switch to the external drive, simply restart your Mac and hold down the Option (or Alt) key again. Select the external drive as the boot disk, and the Mac will boot from the external drive instead of the internal drive. You can also set the default startup disk in System Preferences, which will allow you to boot from the selected drive without needing to hold down the Option key.
Are there any limitations to running macOS from an external hard drive?
Yes, there are some limitations to running macOS from an external hard drive. For example, the drive may not be able to take full advantage of the Mac’s hardware capabilities, which can result in slower performance and reduced battery life. Additionally, some features like FileVault encryption and APFS encryption may not work properly on an external drive.
It’s also important to note that not all Macs are compatible with booting from an external drive, so you may need to check your Mac’s specifications before attempting to set this up. Additionally, some features like Target Display Mode and Power Nap may not work when booting from an external drive. However, for most users, running macOS from an external hard drive can be a convenient and flexible solution.