It works well when troubleshooting problems with your Mac, especially if you can’t boot from the primary hard drive to access System Preferences. This is an easy way to select a startup disk before your Mac turns on. Your Mac will boot from the startup disk you selected. Click the arrow directly below the drive.Select the disk you want to use as a startup disk. Choosing a Partition Map Mac OS Extended (Journaled) Mac OS Extended (Journaled, Encrypted) Mac OS Extended (Case-sensitive, Journaled) Mac OS Extended (.A screen displaying all of the available startup disks appears. The history on this drive: It is a 2 TB Seagate external hard drive that the Mac store reformatted for me to use with Time Machine. If I mouse over it, it reads: 'Disks with Master Boot Record Partition Maps cannot be partitioned'. Immediately press and hold down the Option key. Within disk utility, the partition icon is grayed out.Press the power button to turn on your Mac.Connect the drive you want to use as a startup disk to your Mac.There’s also a way to select a startup disk immediately after you turn on your Mac. To change your startup disk back to the primary disk, repeat the instructions and select the primary disk as the startup disk. Select the hard disk or partition you want to use as the startup disk.Ĭlick Restart to restart your computer and boot from the selected startup disk.
#MAC OS PARTITION HARD DRIVE HOW TO#
Here’s how to change your Mac’s startup disk:Ĭonnect the drive you want to use as a startup disk to your computer.įrom the Apple menu, select System Preferences. Changing Your Mac’s Startup Disk with System Preferences Normally, the startup disk is set as the hard disk inside of your Mac, but you can use an external hard drive, USB thumb drive, or DVD as your startup disk. When your Mac turns on, it loads the operating system on the designated startup disk, a hard disk or partition containing the macOS operating system. But if you forgot to backup your disk and lost some files after partitioning, dont worry. Actully you can avoid this by backing up your disk before partitioning your Mac.
#MAC OS PARTITION HARD DRIVE MAC OS X#
AirPort Apple Apps Backups Developer Education Email Hardware Internet iPad iPhone Mac Music Network Photos Security TV Weekend Wonk How To Partition A Hard Drive Mac Os X 10.6 Risks of Partitioning A Mac: When you partition your hard drive on Mac, a main risk of that is data loss.