Big Sur: Read this before upgrading

Later today, you’ll be enthused by Apple’s event to upgrade your Mac to Big Sur. While that may well be a great choice, before you do, please take a careful read through the following articles here. They’ll spare you a lot of frustration and maybe even having to reformat your internal storage and re-install your previous system. Big Sur is wonderful and ready to go, but don’t rush it.

Many experienced Mac users like to leave it a while before committing their main, production Mac to a new version of macOS. This article looks at some of the issues involved, with particular reference to Big Sur. If you still want to be an early adopter, then this article gives practical advice on what you should do to prepare for the upgrade.

One of the major changes in Big Sur is its new Signed System Volume, which greatly increases the security of macOS system files. This article explains more about it, and how you can disable that when necessary. However, if you think from the outset that you might need to turn it off, you should ask yourself whether Big Sur is a good choice at all.

This article explains in detail how Big Sur changes the layout of its boot Volume Group, and provides handy reference charts. One significant file system issue which you should bear in mind is that the first release of Big Sur may still not fix the problems with cloning System volumes explained here. However, we hope that asr has been fixed properly in the release version.

If you’re thinking of a dual-boot system, which can run either Big Sur or an older version of macOS, you might like to read of the complexities of some paths, and other cautions.

There may also be some problems which arise in apps and scripts, as the result of the change in version numbering. This article examines those over a range of languages and scripting systems.

Making the leap to Apple Silicon Macs also has some important considerations. This article considers problems that can arise with apps, both in Big Sur generally, and when running on Apple Silicon Macs. One important change with those new models is that they require all ARM-native executable code to be signed, unlike Intel models which can continue to run unsigned code in Big Sur. This article explains. Finally, mixing Intel and ARM code on Apple Silicon Macs isn’t going to be a good idea, as this article explains.

As with Catalina, upgrading to Big Sur involves commitment. Should it prove a disaster, the road back isn’t quick or easy: you’d need to reformat your boot disk and install a fresh copy of the previous version of macOS. It’s also worth noting that, however alluring it might be that Big Sur can make Time Machine backups to APFS volumes, those are incompatible with previous versions of Time Machine, and converting old backups for use with Big Sur is also likely to be a one-way trip.

Whatever you choose, I wish you success. To help you, the great majority of my free utilities are not only compatible with Big Sur, but also Universal Apps, which run native on both Intel and Apple Silicon Macs. You’ll find a menu below, and in this downloadable PDF: AppSelectionChart