Apple’s Trade In scheme is so attractive. What better time to exchange that flagging and slowing Mac for a shiny new Apple silicon model? Or maybe you’ve found a purchaser for your old Mac, or decided to pass it on to a friend or relative. This article considers how you should prepare to part with your old Mac, and get started with its replacement, in response to a recent surge in problems I’ve been asked to help with.
If you’re planning to buy or are already committed to a new Mac and parting with your old one, you must ensure that you don’t lose essential documents or data in the process, and that your old Mac is completely wiped.
Back up
The most obvious essential step in preparing to upgrade is to make a full backup of all your documents and data on your old Mac. If you use Time Machine to do that, it’s also essential to take note of how that backup is made and stored. Up to and including Catalina, your backups will be kept on a traditional HFS+ volume, a format no longer used for backups in Big Sur and later. However, if your old Mac was upgraded to Big Sur or later, you may have taken the option to continue backing up to HFS+ rather than starting a new backup set on APFS.
Although Monterey and later can migrate from old backups on HFS+ format, they may also prove keen to reformat your backup storage to APFS ready for new backups. If that happens, you’ll lose all your old backups. Forever.
One simple way to tell the old and new backup stores apart is to look at them in the Finder: old HFS+ format backup volumes have a top-level folder named Backups.backupdb containing your backups; new APFS format backup volumes just contain a long series of special backup ‘folders’ named by datestamp. If you’re still in doubt, open Disk Utility, select the backup volume and it will tell you whether it’s in HFS+ or APFS format.
Extra copies
As your old Mac is about to be lost forever, don’t be satisfied with just a backup. Make an additional copy, preferably on a different disk, of all the important files on its internal storage. In addition to the visible files in your Home folder, consider exporting your passwords from Safari, encrypting that file, and keeping that with those documents. Some may also need to preserve personal security certificates stored in their keychain: Keychain Access in Utilities can do that. Certificates are particularly important, as they’re only stored locally and aren’t shared using Keychain in iCloud.
iCloud
Sharing data in iCloud is a real boon whenever you upgrade Macs or devices, as once your replacement has been signed into that iCloud account, all that shared data is synced down to it. Even if you don’t want to do this all the time, and migration does a good job, it will still save you a lot of worry. Remember, though, that Keychain in iCloud shares passwords but not security certificates, which you’ll need to transfer separately if they don’t get migrated.
Cleaning up
Once you’re completely confident that all your old documents and data have been stored outside your Mac, at least twice, now’s the time to wipe the old Mac. If you’re able to set your new Mac up first, then that’s even better, but if the old one has to go at the same time that you get its replacement, you’ll need to get it ready to go.
This process is simplest on Intel models with a T2 chip, and Apple silicon Macs, running Monterey, where most of the work can be done with a single menu command: Erase All Content and Settings (EACAS), which I’ve explained here. You’ll need to:
- deauthorise that Mac for iTunes
- run EACAS
- remove that Mac from your account in the Apple ID pane.
If, as is more likely, your old Mac is an Intel model without a T2 chip, EACAS isn’t available to you, and you’ll have to do it by hand, as I’ve explained here. The steps are then more numerous:
- disable Find My Mac and Activation Lock
- deauthorise that Mac for iTunes
- sign out of iCloud
- sign out of iMessage
- disable any firmware password
- reset NVRAM
- unpair Bluetooth devices
- erase the Mac and install macOS
- remove that Mac from your account in the Apple ID pane.
Whichever you do, start by deauthorising any third-party apps, and migrating any licences and accounts required to support apps to be run from your new Mac.
Setting up your new Mac
You’ve now lined everything up for a trouble-free migration to your new Mac. When you start it up and begin the process of personalisation, ensure your Time Machine backup disk is connected by the fastest means possible, such as Thunderbolt 3 or USB 3.x over USB-C. Unless you’re going to perform a manual migration, take advantage of using migration either during initial setup or later.
If your new Mac has been delivered with a recent version of Monterey pre-installed, then migrating during setup makes good sense. Sometimes new Macs ship with significantly older versions pre-installed: in that case, I prefer to set it up with my primary admin user account but defer migration until after I have brought its macOS up to date. This ensures that it uses the most recent migration, which often works better. You can always run Migration Assistant in Utilities at a more appropriate time. You can read more about migration here.
If you’re migrating from Time Machine backups, be very careful with Time Machine on your new Mac. If you can, keep your old backups as an archive, and start a new set of backups on a fresh external disk. Then if you ever want to find an old file that seems to have gone missing, you can connect your old backup storage and check through that using the Finder. If you must make your new backups to the same disk, prepare an APFS volume for the purpose, before enabling Time Machine.
Open Disk Utility and select your backup disk. To create an APFS volume suitable for Time Machine backups, you’ll need to add a new partition (APFS container) to the disk. That’s not always possible if the disk is already fairly full, something the Partition tool should warn you about. If that can be performed without deleting the original HFS+ volume, then you’ll need to add an APFS volume to store your backups. That will be in Case-Sensitive format, although Time Machine will probably re-create it for you anyway.
Once you’ve got storage ready to keep your backups, set up any excluded volumes or folders using the Options… button in the Time Machine pane before setting your new volume using the Select Disk… button. When you’re confident that won’t destroy your old backups, start automatic backups.
Finally, welcome to your new Mac.
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