I’ll admit it: I’ve gotten a little used to working at smaller companies, where there’s no monitoring of company computers, and it’s the Wild West as far as what you can install on them.
That’s no longer the case for me. I now work at Auth0, a company with a headcount that’s quickly approaching 800, with unicorn status and Series F funding, and it’s in the security industry. Naturally, there’s a full-fledged security team that monitors company-issued computers.
1- Design: Described by Apple this new move from macOS 10.16 Catalina to macOS 11 Big Sur. Since the introduction of Mac OS X, this is the biggest design upgrade in macOS Big Sur vs Catalina. Yosemite bought its iOS flavored remodel to the Mac and changed the look of Mac OS X back then.
In my excitement to take the new version of macOS — Big Sur — out for a spin, I’d forgotten that the Security team hasn’t yet approved it for use. They very quickly (and I should add, nicely) contacted me and let me know that I needed to reinstall macOS Catalina as soon as possible.
There are other reasons why you might need to go back to Catalina after installing Big Sur:
For the benefit of any who need to downgrade, here’s a step-by-step guide to reinstalling Catalina after you’ve installed Big Sur. You’ll need a USB key and the better part of an afternoon.
The first thing you’ll need is the macOS Catalina installer.
It’ll take up around 9 gigabytes of space on your hard drive, and the App Store will put in your Applications folder.
Once it’s completely downloaded from the App Store, the installer will start automatically. When this happens, close the installer. You’ll make use of it later.
The installer will take some time to download. Apple’s servers will be busier than usual, as many users are downloading Big Sur and other upgrades.
In the process of reinstalling Catalina, you’ll need to completely erase your Mac’s hard drive. If you have any files that you can’t live without, this is the time to back them up.
I didn’t have to worry about this, since:
The process will involve booting your Mac from a USB key containing the macOS Catalina installer, so you’ll need a key with enough space. An 8 GB USB key won’t be big enough. Because digital storage is all about powers of 2, the next size up will be 16 GB.
I strongly recommend that you use a USB 3 key, especially one with read speeds of 300 megabits/second or better, such as the Samsung Fit Plus. Doing so will greatly speed up the process. Don’t use a USB key that you got as conference swag — it may have the space, but more often than not, they tend to be slow, because they’re cheap.
If the USB key contains files that you want to keep, back them up. You’re going to erase the key in the next step.
Plug the USB key into your Mac, then launch Disk Utility.
Select the USB key in Disk Utility’s left column, then click the Erase button:
You’ll be presented with this dialog box:
Enter MyVolume into the Name field, and for Format, select Mac OS Extended (Journaled). Click the Erase button. This will format the USB key with the volume name of MyVolume.
In Step 1a, you downloaded the macOS Catalina installer and closed it after it started automatically. In this step, you’ll transfer it to your freshly-formatted USB key.
Open a terminal window and paste the following command into it:
(The command above assumes that you gave the USB key the volume name MyVolume.)
Once you’ve provided sudo with your password, you’ll be asked if you want to erase the USB key. Entering Y in response will start the process of making the USB key a bootable drive and copying the macOS Catalina installer onto it:
The Erasing disk process will be relatively quick, but the Copying to disk process may take a while. This is where using a nice, fast USB 3 key will pay off.
Be patient and let it get to 100%, and wait for the Install media now available message to appear and the command line prompt to return.
Check the year of your Mac’s manufacture by selecting About This Mac under the Apple menu:
Here’s how you change the security settings:
Restart your Mac, and hold down the Option key while it restarts. Your Mac will present you with a choice of startup disks.
Choose the USB key. Your Mac will boot up and you’ll be presented with the macOS Catalina installer screen:
Go ahead and install Catalina.
Once Catalina is installed, you can proceed reinstalling your other software.
Once that’s complete:
If your Mac is from 2018 or later, follow these steps to restore the original security settings once Catalina has been installed:
macOS Big Sur elevates the most advanced desktop operating system in the world to a new level of power and beauty. Experience Mac to the fullest with a refined new design. Enjoy the biggest Safari update ever. Discover new features for Maps and Messages. And get even more transparency around your privacy.
macOS Big Sur is compatible with the following computers. If your Mac isn't compatible, you might be able to install an old version of macOS instead.
MacBook introduced in 2015 or later
MacBook Air introduced in 2013 or later
MacBook Pro introduced in late 2013 or later
Mac mini introduced in 2014 or later
iMac introduced in 2014 or later
iMac Pro
Mac Pro introduced in 2013 or later
View the complete list of compatible computers.
If upgrading from macOS Sierra or later, your Mac needs 35.5GB of available storage to upgrade. If upgrading from an earlier release, your Mac needs up to 44.5GB of available storage. To upgrade from OS X Mountain Lion, first upgrade to OS X El Capitan, then upgrade to macOS Big Sur.
If you're using macOS Mojave or later, get macOS Big Sur via Software Update: Choose Apple menu > System Preferences, then click Software Update.
Or use this link to open the macOS Big Sur page on the App Store: Get macOS Big Sur. Then click the Get button or iCloud download icon.
After downloading, the installer opens automatically. Click Continue and follow the onscreen instructions.
Please allow installation to complete without putting your Mac to sleep or closing its lid. During installation, it might restart and show a progress bar or blank screen several times. You might find it easiest to begin installation in the evening so that it can complete overnight, if needed.
After installing macOS Big Sur, you will be notified when updates to macOS Big Sur are available. To check for updates, choose Apple menu > System Preferences, then click Software Update.