Preparing to upgrade to Mojave: a checklist

In a few days, Apple will be offering us its next major release of macOS, Mojave. I have already considered whether you should choose to be an early upgrader. Here is a short checklist which should help you prepare for the forthcoming excitement, and help make it exciting rather than a nightmare.

Is your Mac compatible?

This might seem an obvious matter, but if it’s an older model, it is worth checking carefully to be certain. The official list currently reads:

  • MacBook8,1 Early 2015
  • MacBookAir5,1 mid 2012
  • MacBookPro9,1 mid 2012
  • Macmini6,1 late 2012
  • iMac13,1 late 2012
  • MacPro6,1 late 2013
  • MacPro5,1 mid 2010 with suitable graphics cards (this is worth checking carefully if you are not already running High Sierra)

and all later models. Because this list is based primarily on GPU compatibility, it seems unlikely that there will be any hack or cheat which extends it to earlier models.

Is your other hardware compatible?

The most obvious to check are printers and scanners. However, Apple hasn’t dropped support for any for some time, and its current list for recent versions of macOS has remained static: you can check that here. For other devices, check with their vendor that they are fully compatible with High Sierra at least, which should be a good guide. If they’re still not ready for High Sierra, ask the vendor to confirm.

Will key apps and services work?

Are you using any services or apps which either aren’t supported in Mojave, or may cause initial problems? Apple’s Back to My Mac won’t work, so you’ll need to make alternative arrangements before even looking at upgrading. Adobe CS apps often require updating and it’s best to wait for Adobe to give the all clear before upgrading. Ensure that all your other critical apps and software are updated/upgraded/replaced first.

If necessary, prepare workarounds

If you know in advance that some apps won’t work with Mojave, you have options which can keep them running while that Mac is upgraded. One effective solution is to run them in an older version of macOS such as Sierra, inside a Virtual Machine (VM) in the likes of VMware. I have set this up on an old MacBook Air, and in most cases it works really well.

The other approach which can prove excellent is to set up a dual-boot system, which can start up in either Mojave or High Sierra. I’ve been using such a system during Mojave’s beta testing, and it has worked faultlessly for three months. This is good when you want to swap between those two versions of macOS, but less likely to work well with Mojave and Sierra, for example.

If you choose either of these, get as much up and running as you can before you upgrade to Mojave, and check that they work (as far as you can).


When you do upgrade to Mojave, you don’t want it to start with loads of potentially troublesome apps and incompatible drivers and extensions. Set aside some time now to have a really good housekeeping session to make your current Mac sleek and ready to upgrade.

Backup, backup, backup

You can’t have too many backups before you upgrade. Not only is this important to safeguard you from problems resulting from the upgrade, but it’s an excellent opportunity to ensure that your Mac is thoroughly backed up. I aim to cover two possibilities: total data loss from my startup disk, and the possibly hidden corruption or loss of important documents.

For many, the primary backup will be by Time Machine. This is a good time to check that you can really retrieve a few important files from your backup. Don’t just assume that because it seems to have been working OK for the last few months, you can rely on that backup to get you out of trouble.

If you’re backing up to iCloud, this is one occasion where I would want a complete local backup. What happens if after the upgrade, you can’t establish a reliable connection with iCloud?

In addition to regular backups, I like to make a clone or mirror copy of the disk that I’m about to upgrade. This is particularly important if you’re about to ask the Mojave installer to convert your Fusion Drive to APFS. Although by now that should be reliable, having a clone made using Carbon Copy Cloner or SuperDuper is excellent insurance.

If your startup disk is already in APFS format, then you have another option open, which I encourage you to use: a snapshot. The Mojave installer should make one of these automatically at the start of its installation process, but there’s no harm in making one yourself for safety. You can do this in some tools, including Carbon Copy Cloner, or in Terminal using the command
tmutil snapshot

In theory, with a snapshot in place it should be very easy to roll back to your last system. In practice, that may not be possible if some of your old files have already been overwritten during the upgrade. The more free space you have on your startup disk, the more likely you are to be able to roll back if you need to.

Allow time

Things only go wrong when you’re pressed for time, and when you don’t have time, sorting them out is much more difficult. Don’t rush in and try to be the first to upgrade when Mojave is released – wait until you can set aside sufficient time to allow for any problems.

Standby preparations

If you use your Mac entirely for leisure, and are only mildly inconvenienced if it’s out of normal use for a day or two while you sort out post-upgrade problems, then don’t worry about preparing a standby system. For most of us, though, we need access to email, iCloud, and some essential work tools and documents. If that’s the case, get that Mac set up well in advance, and ensure that it is properly synced. Like everything else in insurance, it’ll help ensure that your upgrade goes well.


Don’t get carried away by the upgrade experience. Once the Install macOS Mojave app has downloaded, and before you get stuck into it, make at least one copy of it, preferably on another disk.

This gets more complex if Apple tries another two-part installer, as it did to begin with for High Sierra. As none of the beta releases have tried to use that mechanism, you should just have the one very large app to copy into safekeeping. You can also use that later to build yourself a USB memory ‘stick’ as a bootable installer.

During the upgrade itself, whatever you do, don’t panic. Some upgrades do take a very long time, and knowing when to give up as frozen is not easy. This is particularly important for those converting a Fusion Drive to APFS. Installers sometimes support a verbose listing mode which you may be able to turn on by pressing Command-L.

If you do force a shutdown or restart as a last-ditch measure, start up in Recovery mode using Command-R and try reinstalling macOS from there. Some upgrades in the past have dropped straight back into the upgrade process, and gone on to complete the installation fine.

I wish you success, and look forward to seeing you here in Mojave.