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How to Prepare Your Mac to Upgrade to macOS Big Sur: the Ultimate Guide

Posted on November 18th, 2020 by and

Another year, another new version of macOS. Apple has released macOS Big Sur, also known as macOS 11. Apple’s new desktop operating system features the biggest interface change since the release of Mac OS X, and while there aren’t a lot of flashy new features, everything will look different.

Should you upgrade your Mac to Big Sur? Is your Mac compatible with the new operating system? And how should you prepare for this big change? In this article, I’ll answer all those questions, so you can be ready to upgrade your Mac to macOS Big Sur when Apple officially releases its new operating system.

Upgrade Now, or Upgrade Later?

If you’re reading this shortly after macOS Big Sur’s initial public release (on or within a few weeks after November 12, 2020), you should be aware that this is the first time that most people in the world have ever experienced the new operating system. It’s likely that a few bugs and compatibility issues will be discovered and fixed soon, although any such bugs may not necessarily affect you.

Some Mac users, as a general rule, prefer to wait a few weeks for the initial bugs to be worked out and patched, and for more information to become available about compatibility with third-party apps and hardware, before upgrading to the latest macOS. Other Mac users are excited to embrace bleeding-edge macOS advancements and will prefer to upgrade immediately.

Regardless of whether you prefer to upgrade immediately or wait a few weeks first—or if you haven’t yet decided which category you fall into—read this guide carefully to make sure you’ve made all the important considerations before taking the leap into the next-generation Mac operating system.

Mac Model Compatibility

The first thing to check is whether your Mac model is compatible with Big Sur. The following Macs can run Big Sur:

  • iMac (2014 and later)
  • iMac Pro (2017 and later; all models)
  • Mac Mini (2014 and later)
  • Mac Pro (2013 and later)
  • MacBook (2015 and later)
  • MacBook Air (2013 and later)
  • MacBook Pro (Late 2013 and later)

If you’re not sure of the vintage of your Mac, go to the Apple menu, and choose About This Mac. You’ll see its model and year.

Compatibility of Security Software and Hardware Drivers

Intego X9 software boxesIn macOS Big Sur, Apple made a major under-the-hood change: legacy kernel extensions (kexts) have been deprecated in favor of new “system extensions” that behave very differently. This primarily affects security protection and network monitoring software, as well as drivers (software that enables your Mac to work with certain third-party hardware).

If you care about your security and privacy, you probably use software such as an antivirus or firewall (including Intego software), or VPN software. It’s critically important to upgrade these to the latest versions before you upgrade to macOS Big Sur. Intego’s X9 apps are compatible with macOS Big Sur as long as you’re fully up to date, so be sure to run NetUpdate to verify that you have the latest versions.

It’s also very important to check that any hardware drivers you rely on are compatible. For example, if you use a RAID storage device, and its driver isn’t updated, you won’t be able to access your files on that device; and if you have a graphics card whose drivers are not part of macOS, you’ll need to make sure they have been updated to use your Mac correctly. You may also want to verify that there are Big Sur compatible drivers for your printer or any other hardware that may rely on custom software for special features. Although some printers, scanners, and other common hardware may work fine without any custom software, you may not know for sure about your own peripherals until you try them with Big Sur.

Compatibility of Apple and Third-Party Software

Any software that’s actively developed by Apple should be fully compatible with Big Sur. Many major third-party apps will work as well, but there’s a possibility that one or more apps that you depend on won’t be, especially older apps that may no longer be updated.

In some cases, third-party app developers might not yet have finished developing a Big Sur compatible version, and in rare cases it may not be possible to make their apps compatible. If there are any apps you can’t live without, it is essential that you check to make sure that your apps are compatible. Imagine if you don’t, and you find that one app you use to perform an important task for your clients doesn’t work! You might be forced to rely on your system backup (more on that below) and try to revert back to Catalina.

Apple does not maintain a list of compatible third-party apps, but you can find unofficial lists in various places, such as Reddit threads like this one or sites like RoaringApps that try to crowdsource this information. Each app developer should say on their websites, or in Mac App Store information, whether they are compatible. But in some cases, especially for older or infrequently updated apps, you may not know unless you contact the developer.

Rosetta 2 logoNote that if you’re buying a new Mac with Apple Silicon (i.e. an Apple M1 processor, rather than an Intel processor), you may also want to check a site like Does it ARM? (Apple processors are based on the ARM architecture) or contact the developer to ask whether their software will work on Apple Silicon Macs. In general, most apps that are compatible with macOS Big Sur should work with little or no additional development effort due to Apple’s “Rosetta 2” technology, which allows apps designed for Intel Macs to run on new Apple Silicon-based Macs. However, there may be some exceptions where developers will need to update their apps for compatibility with new Mac hardware.

Clean Your Mac

It’s a good idea to update as much of your software as possible before upgrading to Big Sur, because in many cases updates will be available that are compatible with the new operating system before its release.

Most apps these days offer automatic update features, or, if you’ve purchased them from the Mac App Store, you can get updates via the App Store app. Updating is especially important for software like the Microsoft Office suite, the Adobe Creative Cloud apps, or other apps you may depend on for your work.

Another thing you can do is clean out some of the gunk that has been on your Mac for a while. You can start by choosing the Apple menu > About this Mac, then clicking on Storage.


How to Use Optimized Storage to Increase Disk Space

You can also use Intego Washing Machine (available as part of Mac Premium Bundle X9, Mac Washing Machine Secure X9, or standalone) to clean up and delete files you no longer need, such as cache files, downloads, duplicates, and more.

Check Your Drive

Apple’s Disk Utility (located in /Applications/Utilities) is a tool designed to manage disks, but also to check them for errors. Before upgrading, it’s a good idea to run Disk Utility’s First Aid tool on your startup volume, as well as on the disk(s) you will use to back up your Mac (see below).

Launch Disk Utility, select your startup volume, then click First Aid in the toolbar. This will take a few minutes, and during the process your disk will be locked so Disk Utility can make repairs, if necessary. When this is completed, it will tell you if all is well, and if it has made repairs.

Back Up Your Mac

If your Mac is compatible, and you’re ready to upgrade, the first thing you should do is back up your Mac. You can use Time Machine if you have an external hard drive, but the safest way to do this is to clone your drive. A clone, or bootable backup, is an exact copy of everything on your Mac’s drive: system files and personal data. You can do this with Intego Personal Backup.


Intego Personal Backup Compared with Apple’s Time Machine

If anything goes wrong during the upgrade process, you can boot from the external drive, and, if necessary, recopy all its files to your Mac.

And, of course, you can always take a belt-and-suspenders approach and do both. That way if something goes wrong with restoring a backup, you can feel secure knowing that you have an alternative option.

Choose Upgrade Method: Migration or Clean Installation

There are two ways to upgrade a Mac. The simplest is to run the macOS Big Sur installer, which will install the new files over your existing operating system. It won’t alter your personal data, but only those files that are part of the system, as well as bundled Apple apps.

The other is to use Apple’s Migration Assistant. This app is designed to move your data from an old Mac to a new one, but you can also use it for an upgrade. To do this, you should clone your Mac, on at least two drives (one to use for the upgrade, and another as a backup). Start up your Mac, then press the Option key immediately so you can select a cloned drive as the startup drive. Launch Disk Utility (in /Applications/Utilities) and erase the drive on your Mac. (You did make two backups, right?)

Download the macOS Big Sur installer and launch it. It will ask which drive you want to install the software on; select the now erased drive in your Mac. Follow the instructions to complete the installation.

When you’ve finished, you’ll have a virgin operating system on your Mac, and you’ll still be working from your external drive. You can now copy all the files in your home folder, as well as personal apps.


Setting Up a New Mac: Should You Migrate or Do a Clean Installation?

A clean installation is time consuming, but it can weed out old files from apps you no longer use, and it’s a good way to start with a clean slate. Some people do this for every major operating system upgrade; I only do it every few years, because it does take a long time. If you do a clean installation, make sure to keep both of your clones for some time, just in case there’s something you forgot to copy over.

How to Install macOS Big Sur

Okay, it’s taken a while, but now you’re ready. If you’re installing macOS Big Sur on a laptop, make sure it’s charged, or connect it to a power supply; you don’t want it running out of battery during the installation process.

Apple macOS Big Sur official logoGo to the Mac App Store and download the Big Sur installer. The update is over 12 gigabytes in size, so it will may take a while to download, depending on your bandwidth. When the download is complete, the installer will launch; follow its instructions. The upgrade process can take a while—expect it to take a half-hour or more—and this is a good time to get a cup of tea or coffee, walk the dog, or do something else instead of sitting in front of your Mac watching its progress bar.

But before you start the upgrade, you should be aware that after macOS is installed, the installer is usually deleted automatically. If you look in your Applications folder before starting the upgrade, you’ll see the installer app, called Install macOS Big Sur. It’s a good idea to make a backup copy of this app in another location: an external drive, or perhaps your Downloads folder. This can be handy in case something goes wrong and you need to run it again. This is also useful if you have more than one Mac and want to avoid having to wait to download the Big Sur installer again; you can just copy the installer app to another Mac and run it.

Once the installation is complete, you may need to go through a few screens, such as one to sign into your iCloud account. At this point, you may see an Incompatible Software screen telling you of apps that have been moved because they are known to be incompatible. You’ll find them in an Incompatible Software folder at the top level of your drive.

What to Do if Something Goes Wrong

Many things can go wrong with an operating system upgrade. If you have a problem, you can boot your Mac from the clone you made earlier, then run the installer again. In a worst-case scenario, you may need to wipe your Mac’s startup drive, the follow the clean installation method I discussed above.

Even if all seems well, keep your clone or backup for a while, just in case something goes wrong within the first few days or so. Now you can start checking out some of the new features in macOS Big Sur. Enjoy!

How can I learn more?

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About Kirk McElhearn

Kirk McElhearn writes about Apple products and more on his blog Kirkville. He is co-host of the Intego Mac Podcast, as well as several other podcasts, and is a regular contributor to The Mac Security Blog, TidBITS, and several other websites and publications. Kirk has written more than two dozen books, including Take Control books about Apple's media apps, Scrivener, and LaunchBar. Follow him on Twitter at @mcelhearn. View all posts by Kirk McElhearn →