By default, your Mac starts up from its built-in hard disk, but a startup disk can be any storage device that contains an operating system compatible with your Mac. For example, if you install macOS on an internal or external drive, your Mac can recognize that drive as a startup disk. You can then follow the steps in this article to start up from it.

Use Startup Disk preferences

Also note: Disk Drill does provide a separate feature to install a new instance of Mac OS X using the bootable drive that can be created with it. However, this article explains the steps required to create the Mac OS X USB boot disk for lost data retrieval and running Disk Drill in a ready-to-use standalone recovery environment. Oct 30, 2017 How to Fix an Almost Full Startup Disk for Mac OS X. If you are receiving the message that your startup disk is almost full on OS X, you can fix this following the steps below. Know what the message looks like. This image shows the. If the volume contains OS X, start your computer from OS X Recovery and use Disk Utility to repair the volume, or reinstall OS X on the volume using the Recovery System. Depending on the Mac you are using and the version of OS X that is installed, the Recovery System volume (Recovery HD) might not show up in Startup Manager. Backup your complete MAC OSX hard drive, then when there is an issue boot from the MAC Recovery disc and easily recover from the backup. The Mac recovery system includes a drive diagnostic system to determine if the drive has failed. For Warranty support from Apple, you required to obtain your own backup when the hard drive has failed.

When you use Startup Disk preferences to select a startup disk, your Mac starts up from that disk until you choose a different one.

Choose Apple menu  > System Preferences, then click Startup Disk.
Click the lock and enter your administrator password.
Select your startup disk, then restart your Mac.

If you see a message that your security settings do not allow this Mac to use an external startup disk, check the External Boot setting in Startup Security Utility.

Use Startup Manager

When you use Startup Manager to select a startup disk, your Mac starts up from that disk once, then returns to using the disk selected in Startup Disk preferences.

Press and hold the Option (Alt) key immediately after turning on or restarting your Mac.
Release the Option key when you see the Startup Manager window.
If your Mac is protected by a firmware password, you can release the key when you're asked to enter the password.
Select your startup disk, then click the arrow under its icon, or press Return.
If you press and hold the Control key during this step, your selection is saved in Startup Disk preferences, so it persists until you change it.

If your Mac is using OS X Lion 10.7.3 or later, you can also use this method to start up from your Time Machine backup disk. Startup Manager identifies your Time Machine backup as ”EFI Boot.”

If you can't select your startup disk or start up from it

Mac Os X Startup Disk For Sale Near Me

Check for these possibilities if you can't see your disk in Startup Disk preferences or Startup Manager, or your Mac won't start up from it.

Check for a compatible operating system on the startup disk

Make sure that your startup disk is using a version of macOS that is compatible with your Mac.

To start up from an external disk with macOS Catalina 10.15 or later, the disk must connect via USB-A, USB-C, or Thunderbolt, not FireWire.

Check startup security settings

If you're using a Mac that has the Apple T2 Security Chip, check the settings in Startup Security Utility. These settings determine whether your Mac can start up from another disk.

Check for Option ROM firmware

If you're in Startup Manager and can't see a third-party startup disk, the startup disk could be using Option ROM firmware. To enhance system security, Mac computers with up-to-date software don’t show devices that use Option ROM firmware until you load their firmware. To do that, press Option-Shift-Command-Period while in Startup Manager. If your startup disk appears, do that each time you want to start up from it or from another disk connected to it.

If you're using a firmware password, the ability to load Option ROM firmware is disabled as an additional security protection.

Your Mac has a native application called Disk Utility to create a or partition. A disk image is a file that emulates a drive or volume whose image it contains. Also, the disk image file stores other files & folders just like a virtual drive and can be mounted as a volume within Finder. Generally, the native disk image format of macOS has the .dmg file extension.

In this blog, we’ll share the Disk Utility method to create a disk image file of your Mac startup disk. We’ll also share how to restore your startup disk by using the already created image file.

The need for Creating Disk Image of Mac Startup Disk

You can create a disk image of your Mac startup disk:

·To burn the startup disk’s data to CDs or DVDs

·To back up your startup disk’s apps and settings

·To restore your Mac from the recovery image file

·To compress the startup disk’s data for archival purpose

·To protect startup disk’s files and folders through encryption

·To transfer startup disk’s files and folders between Macs

·To store the startup disk’s data in NAS or a different volume

Prerequisite

To create a disk image of your Mac startup drive, you need any one of the following save locations with sufficient space:

·Additional volume on your Mac

·Mounted external storage drive

·Connected network storage drive

What is next upgrade for os x 10 11.6. You can upgrade to OS X El Capitan from on any of the following Mac models.

Methods to Create Disk Image of Startup Disk

First Method

First off, quit or stop any apps and services to minimize writing on to the startup drive during the image creation process. Subsequently, perform the following steps to create a disk image of your Mac startup disk:

1.Go to Applications > Utilities > Disk Utility.

2.On the Menu bar, select File > New Image > Image from Folder.

3.On the dialog window, select your startup disk (Macintosh HD) then click Open.

4.Provide a name for the disk image, add tags if needed, and specify a save location.

5.If you wish to encrypt the disk image, then click the Encryption pop-up menu and choose an encryption option.

6.Click the Image Format pop-up menu, then specify an image format. You can choose from Read-only, Compressed, Read/write, DVD/CD master, Hybrid image (HFS+/ISO/UDF)

7.Click Save