Upgrade Using Plan A: In-place Upgrade

Now that you’ve gone through all the preliminary steps, it’s time to begin the upgrade. For most people, Plan A—essentially letting the installer do what it wants to do—is the logical choice. And remember, if it doesn’t work out for any reason, you can always move on later to Upgrade Using Plan B: Clean Install. Nevertheless, because you may encounter some questions or confusion during the process, I detail exactly what steps to take from start to finish.

Start the Installer

Unlike installers of old, the Sierra installer requires no separate startup disc; you simply run an app and it does its thing. However, if you haven’t already done so:

• If you are installing onto a laptop, connect its AC adapter to a power source. (If you forget to do this, the installer will prompt you.)
• Quit all open apps. (The installer attempts to do this for you—and prompts you if it can’t—but you might as well take care of this beforehand.)

To begin the process, double-click the Install macOS Sierra icon in your /Applications folder or wherever else you put it. A window appears with just one button: Continue. Click it!

If you happen to be installing the Sierra public beta, you’ll see an additional alert here urging you to have a current backup of your data. But you already do—right?—so just click Continue. (If you don’t, go back and read Back Up Your Disk.)

The Software License Agreement appears next; click Agree, and then click Agree again in the confirmation dialog to proceed.

Select a Destination

The next screen asks you confirm which volume you want to install Sierra onto. In most cases, it displays its best guess—typically your startup volume (Figure 6)—but in some situations you may see multiple disks here, in which case you should select the one you want. To install Sierra onto a volume that’s not shown, click Show All Disks to display all available options and then make your selection.

If the installer can’t use a volume as the destination for any reason, that volume is dimmed; click it for an explanation. Note that you can’t install Sierra onto:

• A disk that uses a partition map scheme other than GUID Partition Table (see Prepare Your External Drive)
• A volume formatted using anything other than Mac OS Extended (Journaled), with or without case-sensitivity or encryption; you’re prompted to reformat it using Disk Utility
• A volume containing an installation of 10.5 Leopard or earlier

With your desired destination volume selected, click Install.

Next, you’re prompted to enter your administrator credentials (in order to add a helper app); do so and click Add Helper.

The installer begins copying files. The copy process may take only a few moments or it may take several minutes, but when it finishes, the installer tells you that it will restart your computer automatically in 30 seconds; you can also click Restart to restart immediately. If any applications are still open and the installer is unable to close them automatically (for example, if there are unsaved changes you must respond to), the installer displays a prompt asking you to click Close Other Applications.

Organize Your Pantry

Depending on the speed of your computer and hard disk or SSD, installation may take less than a half hour or as long as several hours. Apart from the steps you’ve already performed, the process normally requires no intervention until the very end. While the remainder of the installation proceeds, you won’t be able to use your Mac for anything else, so now’s a good time to organize your pantry, call your mom, or go for a jog—you have a bit of time to kill.

As the installer progresses, your Mac will restart one or more times, but the startup chime may not play. At the end of the installation, you’ll continue with several additional configuration steps.

Finish Setup Assistant

What happens next depends on how your Mac was previously set up:

• If you had Automatic Login turned on previously, Sierra logs you in automatically.
• If Automatic Login was off, your entire screen becomes a login screen. Select (or enter) your username if necessary, enter your password, and press Return to log in. This initial login process may take longer than usual, so be prepared to wait a few minutes before the login screen disappears.

The first time you use Sierra, macOS Setup Assistant runs, although you won’t see that name—it looks like a continuation of the installer. With an in-place upgrade, this program has little to do compared with a clean install—most of your settings are already in place.

Depending on which version of OS X you’re upgrading from and your previous settings, you may see one or more additional screens:

• Enable Siri: This screen has a single checkbox, Enable Siri on This Mac, which is selected by default. Leave it selected to enable Siri voice control after Sierra is installed, or deselect it to disable Siri. (Either way, you can always enable or disable Siri later—go to System Preferences > Siri once Sierra is up and running.)
• Sign in with Your Apple ID: Even if you were signed in to iCloud in your previous version of OS X, this screen may prompt you to sign in again. Depending on the circumstances, you may be asked only for your password, or for both your Apple ID and your password. If you have to enter both, be sure you’re using the right Apple ID (as discussed back in An Apple ID):
  • To use one Apple ID for everything, leave Sign in with Your Apple ID selected, enter your Apple ID and password, and click Continue.
  • To use one Apple ID for iCloud and a different one for iTunes purchases, click the “Use a Separate Apple ID for iCloud and iTunes” link. Enter the Apple ID and password you want to use for iCloud first. Click Continue, fill in the Apple ID and password you want to use for iTunes purchases, and click Continue again. (The option to sign in with separate accounts appears only under certain conditions.)
  • To make a new Apple ID, click Create New Apple ID and follow the prompts.
  • If you don’t want to enter an Apple ID—and are willing to forgo all iCloud features for the present—select Don’t Sign In (your wording may be slightly different), click Continue, and then click Skip again to confirm. (You can enter this information later, in System Preferences > iCloud.)
• Verify Your Identity: If you’ve enabled Apple’s Two-Step Verification for your Apple ID, an extra screen may ask you to choose an iOS device or SMS number to receive a numeric verification code. Make your selection and enter the code to continue. (In my tests, this screen did not appear during in-place upgrades when Apple’s newer Two-Factor Authentication was enabled.)
• Find My Mac: If you hadn’t previously enabled iCloud’s Find My Mac (and Location Services, on which it depends), a dialog appears asking if you’d like to do so. Click Allow to enable Find My Mac, Not Now to do nothing (you can change your settings later in System Preferences > iCloud), or About Find My Mac to learn more.
• Terms and Conditions: Setup Assistant wants to be sure that you’ve consented to a bunch of additional legalese, so it may invite you to read, study, and agree to as many as three different statements: “macOS Software License Agreement,” “Privacy Policy,” and “Game Center Terms and Conditions.” Handle these however you want; I’ve found that my lawyer enjoys chatting with me about each paragraph of such agreements in detail (at his usual hourly rates).
• All Your Files in iCloud: If you’ve already signed in to your iCloud account by this point in the installation, Sierra asks if you want it to store all the files from your Documents and Desktop folders in iCloud Drive; it tells you how much storage this will require at this time and whether you’ll need to upgrade your iCloud storage plan to accommodate that data.

  This option is selected by default, but I recommend waiting until after you install Sierra—and even then, thinking carefully about whether you want to upload all that stuff to the cloud. So my suggestion is to deselect “Store files from Documents and Desktop in iCloud Drive” for now, and if you decide later that you want that feature, you can turn it on then—see Other Noteworthy Changes.

• Diagnostics & Usage: Sierra can automatically send diagnostic and usage data to Apple and/or third-party developers to help them track down the causes of crashes and other bugs you may encounter. This information is anonymous and doesn’t contain personal information.

  If you want to send this troubleshooting data in the event that a problem occurs, select Send Diagnostics & Usage Data to Apple. With that selected, you may also select Share Crash Data with App Developers. (You can’t share crash data with app developers unless you also share diagnostic data with Apple.)

• iCloud Drive: iCloud Drive makes all your iCloud files available to any app on your Macs (running Yosemite or later) and iOS devices (running iOS 8 or later). If you see an iCloud Drive screen during setup, it’s asking whether you want to switch to this new way of accessing iCloud documents:
  • Answer Not Now if you still need to access iCloud documents using older operating systems on any of your Macs or iOS devices. If you answer Not Now, you can turn it on later by going to System Preferences > iCloud and selecting iCloud Drive.
  • Answer Upgrade to iCloud Drive if all your devices are using (or are about to be updated to) Yosemite or later, or iOS 8 or later.
• Incompatible Software: In rare cases, you may see a screen in Setup Assistant labeled Incompatible Software (Figure 7). If so, glance at it and click Continue; I explain what to do about this software a bit later, in Review the Incompatible Software Folder.

Once you’re through with all that, Setup Assistant displays a “Setting Up Your Mac” screen briefly, then quits automatically and displays your Sierra Desktop.

Check for Proper Operation

In all probability, your upgrade will have gone smoothly, and everything will now work more or less the way you expect. However, even if everything looks fine, don’t declare upgrade victory until you Perform Post-installation Tasks, including dealing with any alerts and queries that pop up shortly after installation, checking for software updates, and configuring a few new options in System Preferences.

If anything did go amiss, or if you later discover problems that aren’t solved by following the advice in Troubleshoot Upgrade Problems, you can fall back to Upgrade Using Plan B: Clean Install.