macOS for Linux Administration

Another reason to install macOS a second time is that your personal and work installations can have different Apple IDs attached to them. This allows you to easily separate your personal Apple ID from one used solely for developing software or as part of an Apple Developer Program for your organization.

To install macOS a second time, you must first create a new APFS logical volume:
Open Disk Utility (/Applications/Utilities/Disk Utility.app).
Click the drop-down menu beside the View button in the toolbar and choose Show All Devices.
Click the + button to create a new APFS volume.
Specify a name for your APFS volume (e.g., work) and optionally set a Reserve (minimum) or Quota (maximum) size if you want to guarantee or limit the space the new logical volume can consume from the underlying partition, respectively.

Next, you can open the App Store, search for macOS Catalina and choose to download it (approximately 8GB). When the download has finished, the installation will start automatically.

At the beginning of the installation, you’ll be prompted to select the volume on which to install macOS. Simply choose the new volume you created (e.g., work) and proceed through the rest of the installation normally.

The new volume will not be encrypted, and the system will automatically boot into macOS installed on your new volume (unless you hold down the Option key at boot time and select your personal macOS installation).

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