Dec 18, 2018 - You can use an external drive or secondary volume as a startup disk. From a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan.

Stellar Partition Manager is an OS X El Capitan compatible software that performs the following activities on Mac hard drives and external drives: (1) Creates & formats partitions with HFS, FAT, NTFS and EXFAT file systems (2) Resizes and removes partition as per user’s requirement (3) Trim and expand BootCamp partition and Macintosh HD (4) Hides & reveals partitions (5) Creates bootable media to resize Mac startup disk drive ** Note: Stellar Partition Manager utility efficiently performs all the above activities on external hard drives as well. This helpful utility is compatible with OS X El Capitan, Yosemite, Mavericks, Mountain Lion, Lion, and Snow Leopard. Below is the process of creating OS X El Capitan bootable media with Mac partition manager utility Step 1: Free demo of the Stellar Partition Manager utility allows evaluation of all the features on your Mac hard drive. To implement these features,. Step 2: Launch the full version of the Stellar Partition Manager utility on OS X El Capitan. Click on the Apple hard drive from the software interface and you will receive the message “ Create Bootable Disk Image”. Please click the button ‘ Continue’ to proceed.

Step 3: In this step, a mini window appears titled ‘ Create Bootable DMG’. It further suggests you to have at - least 8GB of free spaces on your Mac hard drive in order to save the DMG file. Please click ‘ Create Image’ to proceed. Step 4: Upon clicking the ‘ Create Image’ button, the Mac partition manager software will ask you to provide file path in order to save DMG file on Mac hard drive. As mentioned, please give a suitable path, which has good amount of free spaces (8GB recommended) to save this file. Define the path and click Choose. Step 5: Disk creation process of your Mac hard drive begins.

The process is shown in the below image: Step 6: The file ‘ StellarBootImage.DMG’ is saved on your chosen destination. How to make StellarBootImage.DMG file to boot up Mac OS X?

You will be requiring a UBS external hard drive in order to restore StellarBootImage.DMG file using Disk Utility. Process of restoration: Step 1: On OS X El Capitan, launch Disk Utility Step 2: Double click the StellarBootImage.DMG file to mount it on Disk Utility. Also connect your external hard drive to Mac OS X and select it on Disk Utility as shown in the image below: Step 3: Go to Disk Utility ---- EDIT menu and click Restore Step 4: Select StellarBootImage and click Restore to make it bootable. Please view the screenshot below: ** Wait for the restoration process to conclude Your bootable media will be ready in some time. Restart Mac OS X and press Option key before Apple Logo in order to bring Mac startup device manager.

Once the start menu shows, select bootable media to start Mac in bootable environment. In this environment you can create, format, remove, and resize Mac hard drives and logical partitions.

With the release of, Apple took the opportunity to give. You can still use the software to format a startup drive—it’s similar to the steps in the previous version. This how-to goes through the steps of formatting a startup drive using Disk Utility 15 in El Capitan. If you’re using an older version of Disk Utility, the steps are. Connect your drive To format an external storage device, connect it to one of the ports on your Mac. Turn the drive on, and make sure it appears in the Finder.