If the macOS installer can't create a recovery system on your disk, it allows you to continue the installation, but warns that some macOS features won't be available. That can happen in these circumstances:
- You're installing macOS on a RAID volume.
- You're installing macOS on a disk that contains a nonstandard Boot Camp partition: a partition that was manually modified outside of Boot Camp Assistant or was added after using Boot Camp Assistant.
If you're installing on a RAID volume
If you want to use the features enabled by a recovery system, install macOS on a disk that isn't a RAID volume, and use that disk as your startup disk.
If your disk has a nonstandard Boot Camp partition
If you want to use the features enabled by a recovery system, erase the disk before installing macOS:
- Make sure that you have a backup of your disk, including the Boot Camp partition. Time Machine doesn't back up Boot Camp partitions.
- Start up from macOS Recovery over the Internet*: Hold down Command-R on your keyboard immediately after pressing the power button to turn on your Mac, or immediately after your Mac begins to restart. Continue holding until you see the spinning globe.
- Follow the remaining steps to reinstall macOS, including the steps for erasing your disk.
- Use Boot Camp Assistant to create a new Boot Camp partition. Then restore the data from the backup of your previous partition.
* If you can't start up from macOS Recovery over the Internet, use an external startup disk instead.