Boot drive or Startup disk of your Mac is the volume, in which the Mac operating system has been installed. Usually the startup disk of your Mac OS X is Macintosh HD. This boot drive stores all the operating system files and is responsible for booting the machine. Moreover, this is the default location, where all third party software applications get installed.
Mac users always want to use the best and the most recent technology. This is the thought with which many users prefer to use the new versions of Mac operating systems along with their older one. A Mac machine that is installed with two or more operating systems is called as a dual boot machine, in which you can boot from any of the installed Mac operating systems as per your requirement. If you have a dual boot Mac, you must be aware of the below steps to boot using any of the installed operating systems.
Steps to Choose between OS in a multi-boot Mac
While starting up your Mac machine, hold down the ‘Option’ key and you will see all the operating system based partitions. Choose the one you want and that will boot-up.
Switch From One OS to Other
If you are already logged in, go to the ‘System Preferences’ and select the startup disk.
There are instances, when you run out of disk space and on the contrary the boot volume of your Mac still has enough unused space. In such a situation, you may want to trim the unused space from the boot volume, which can be added to any other needy data volume.
However, as the Mac has started-up from the boot volume, various system files in the volume remain in use until the machine gets shut down. Resizing of a volume may involve some sort of shifting of files and in case of resizing the boot volume; it may be needed to shift the system files, which are currently in use by the OS. Hence, such an operation may result in the corruption of the Mac hard drive, resulting in the inaccessibility of all your precious data. Indeed, this is the reason for which the Mac OS does not allow resizing the boot volume while booting from the same.
Here, you can resize your boot volume only if you boot the Mac from a Bootable MEDIA rather than the boot volume of your machine. Stellar Partition Manager provides an option to create a Bootable DMG that can help booting up your Mac. This Bootable DMG contains only the necessary system files needed to boot your Mac and allows resizing the boot volume of your Mac as like any other Mac volume.
To create a Bootable Media using Stellar Partition Manager,Click here