There are times when, for some reason, the operating system of your Mac computer has stopped working (does not start), or has serious errors that affect its daily operation. And for this reason you cannot log in to recover important files.
To solve, the errors that the system presents, start the operating system or rescue the files that you thought were lost, there is the bootable USB, this solution will allow you to have a copy of your operating system in a Pendrive or a Disk Hard or external solid disk.
In this tutorial we will explain how you can boot your MacOS computer from a bootable device and how you can create one in just a few simple steps.
Steps to start the Mac computer from a bootable external USB
The procedure to use a bootable USB device is very simple, but before starting with the explanation there are a number of elements that you must have for the creation of this great tool.
- Device USB (Pendrive) of at least 12 GB or an external storage disk, with the same minimum capacity specified above.
- MacOS installer, these can be macOS Mojave or macOS High Sierra, you can see how install and update Mac software from here . You may be asked to start the installation, once the download is complete, cancel this step .
- Then, the file downloaded for no reason will you will use , just make a backup copy of it in a separate folder , that copy is the one that we will use. To create the bootable device (the method will be explained later)
These are the necessary elements for its creation, now the way to start the device is much simpler than you might think.
Suppose the bootable device has already been created, now it only remains, how to start it on your computer so that you can correct or repair system problems, or retrieve important information.
For this there are two methods, which are:
- The first way is using the « System Preferences» , in it you will have to choose the section that says “Boot Disks” . In this menu you can select the disk that will start when you restart or turn on the computer. The only problem with this is that it can only be used if you have two or more systems functioning correctly. ( That is your classic disk , and the external drive connected and that you can access the main disk to make the configuration setting).
- In case the internal system is completely inaccessible , you have another way to boot the computer, and it is from the external disk. To do this you have to press and hold the “alt” key during the startup of your Mac . In this way you will get all the units connected to the computer to be displayed, select using the arrows on your keyboard the unit that contains the bootable operating system and press Enter to start.
How to create a boot installer for MacOS?
Previously we indicated a list of elements that are strictly necessary, for the creation of a boot installer or a Bootable USB device for MacOS . Added to this must be added that it is necessary to perform this procedure on a computer, without failures.
That is, the equipment you are using at the time of creating this device, has to work in perfect condition, so as to avoid failures when using the external disk or pendrive on another computer.
Steps to create a boot disk in MacOS
These steps can be somewhat complicated, for the user who does not have much knowledge in them, but pay close attention and you can carefully create it.
- Connect the USB device to your Mac computer.
- Wait for it to be recognized by the computer , now you just have to select the device, from the list of disk utility. And click on the delete tab (Erase) .
- Now check that, in the format section, it is specified as follows: “Mac Extended OS (journaling) ” You will find this in the tab« Partition «
- You can modify the name only if you wish.
- Now you will click on delete (Erase ), the button in the lower corner right.
- Wait for the device to erase, and restore it to a new partition.
- Now you are going to use the backup, which you created from the MacOS operating system file .
- Open the “Disk Utility” application.
- You will have to drag the file, which you previously downloaded and backed up, to the white box located to the left of the disk utility application. And automatically the disk image will be added.
- Now reconnect the USB device that you previously formatted. (if you have connected this step obviously).
- Open the window of the disk image again. In the disk utility application.
- Here you will see that the operating system is already added, in the section that says “Source” or “Source”. Now you just have to drag the device (USB drive) that was just formatted, in the section that says “Destination” or “Destination”.
- Finally, you will click on the “Restore” or “Restore” option. Wait, complete the procedure. This may take a long time.
- Once the entire process is finished, you can close the disk utility application.
Check that the device works correctly
Now that the creation of the tool is complete, it only remains to verify that it works correctly. For this, it will only be enough to restart the computer and start from the USB device, of course, you must first configure your computer, so that it can start correctly from a Booteable USB device.
If you haven’t already done so, you must configure it . Once you have done it, choose the corresponding options to load from an external device. If the system starts correctly, the USB device has been created correctly .
In case it doesn’t start, you just have to repeat the steps , always formatting the USB drive you will use, check that it is working correctly before doing any task.
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