Boot From External Dvd Drive Mac

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If you have bought an M1-based Mac or MacBook but need to upgrade your storage without buying a brand new device, you can set up your Mac to run from an external drive. Here's how to boot macOS Big Sur using external storage on the new Mac lineup.

Bootable optical media (CD or DVD) on Macs equipped with Apple’s Super Drive or a USB thumb drive formatted with a GUID partition type and containing a macOS installer or a usable operating system. Apple advises against booting from external storage containing a version of macOS earlier than the one your Mac shipped with. In our test, we created a bootable external hard drive clone of the internal startup drive using ASR. Drawbacks to this external bootable drive are the required initial boot-up check on the first startup. This means that it can take around 20 to 30 mins for all the resources to come back to idle when first booting up into your external hard drive.

The new Mac mini, MacBook Air, and 13-inch MacBook Pro are a tempting purchase for those eager to try out Apple Silicon for themselves. However, not everyone will have picked up a Mac with enough storage to meet their needs.

Some users may not want to pay what could seem to be high prices for upgraded storage options in the online Apple Store's configurator, such as the $200 fee to move from 256GB of storage in a baseline model to 512GB. Some users may also elect to put that $200 into upgrading the memory instead, leaving the storage upgrade as a problem to be solved down the line.

Others may have opted for a lower-capacity model just to get the Mac in their hands quicker, such as via a physical Apple Store, without considering their storage needs.

You can easily store a bootable external Thunderbolt 3 drive on the flat top of an M1 Mac mini.

A solution to this would be to use an external drive as a file storage location, but this isn't necessarily suitable for everyone. There's a lot of work involved in setting all apps to use that external storage, and many will simply prefer to deal with one drive instead of two or more.

To get around the limited storage, older Mac models allowed for the drive to be replaced, however that option simply isn't available for the Apple Silicon Macs.

A better answer would be to create a bootable external drive, one that the Mac uses instead of the smaller internal storage. This guide will explain how to do it.

While this article is more about making it possible to have an M1-based Mac that has more primary storage, the same principle can be used to create a bootable drive for emergencies. If the main macOS installation fails, using an externally-bootable drive will allow a user to quickly get their Mac up and running without touching the internal storage, which can help with file retrieval and backing up before data is lost in a format.

For Intel-based Macs, there are already known processes that can be followed to create the bootable external drive, but the same instructions weren't readily available for M1-based Macs until late December, following experimentation by users.

To create the external bootable drive, you will need a few things to get going. Firstly, you will need an M1-based Mac running on macOS Big Sur 11.1 or later, as earlier releases were problematic.

You will also need to have an external drive to boot from. As well as needing to be sufficient in capacity for your needs and fast, it also has to be compatible with the process itself, so you will need to use a drive that connects over Thunderbolt 3.

We need to stress that the process does require a Thunderbolt 3 drive to work, as you won't have much luck with one using USB-C alone. It seems that something is preventing it from working with USB-C drives on a technical level, but Thunderbolt 3 drives work fine.

In researching the process, various Mac users have found success with non-Thunderbolt 3 drives, but under oddly specific circumstances without any real rhyme or reason for them working. Save yourself the time and just use a Thunderbolt 3 drive from the outset.

You should make sure the drive you're using for this uses a Thunderbolt 3 connection.

This could take the form of a straight external hard drive that uses Thunderbolt 3, or a sufficiently-fast SSD or NVMe in a Thunderbolt 3 enclosure, or an external RAID enclosure that uses Thunderbolt 3. The key here is that it must connect using Thunderbolt 3.

This is a fairly lengthy process, so make sure your external drive is suitable before starting. The last thing you want is to go through all of this and discovering it fails halfway through because you used a USB-C drive instead of Thunderbolt 3, wasting your time and bandwidth in the process.

  1. Open Disk Utility. This can be accessed within the Utilities folder in the Applications list.
  2. Select the drive you want to use for the bootable external storage. Make sure it is the external drive and not the Mac's internal drive, as this is the last chance to make sure.
  3. Click Erase.
  4. Click the Format drop-down box and select APFS. Make sure it is the standard version and not a variant with encryption.
  5. Give the drive a name.
  6. Click Erase, then Done.

There are two ways to actually install macOS Big Sur to the external drive. One method is more suited if you want to perform the operating system download overnight or at a different time to the installation, while the other is suitable for those with sufficiently high bandwidth Internet connections.

How to install macOS Big Sur to an external bootable drive (Download first method)

  1. Open this Mac App Store link. If your browser asks, select to open it in the Mac App Store.
  2. Click Get or the iCloud download icon to download it.
  3. Open the Install macOS Big Sur app.
  4. Click Continue in the installer, and follow the onscreen instructions carefully.
  5. When the installer asks which drive to install macOS Big Sur to, select the APFS-formatted external drive that you want to make bootable, then Continue.
  6. Proceed through the installer to the end.
  7. When the Mac restarts, it will automatically boot from the external disk.
The Mac App Store listing for macOS Big Sur.

This method has users downloading macOS beforehand, then installing it to the external disk as a separate action. It is probably the more favorable of the methods due to freeing up the time for the download to when the Internet connection isn't being used, such as at night or outside of business hours.

The second method, which follows, has users downloading the operating system and installing it as part of the process itself.

How to install macOS Big Sur to an external bootable drive (Download later method)

  1. With the formatted external drive connected beforehand, turn off your Mac.
  2. Turn the Mac back on by pressing and holding the power button, until the screen shows startup options.
  3. Select the Options icon.
  4. Enter an administrator's user credentials.
  5. Select Reinstall macOS Big Sur and follow the onscreen instructions carefully.
  6. When the installer asks which drive to install macOS Big Sur to, select the APFS-formatted external drive that you want to make bootable, then Continue.
  7. Proceed through the installer to the end.
  8. When the Mac restarts, it will automatically boot from the external disk.
One of the menus you will see when installing macOS Big Sur to the external drive.

Both methods leave your Mac with a fresh macOS installation, running off the external bootable drive. You will have to complete the initial Mac setup process, but once that is complete and the desktop is accessible, you can shut down the Mac and disconnect the drive safely.

When you turn the Mac back on, with the bootable drive disconnected, it should automatically select the internal drive and load normally. If not, turn it on with a long press of the power button to bring up the startup options, and select the primary drive.

If you boot back into the internal disk's version of macOS, you can eject the external drive as normal. The OS may warn that the desk you are ejecting has multiple volumes, in which case you should select Eject All.

If there comes a time when you need to boot from the external bootable drive, such as the main macOS installation being corrupted in some way, this can be accomplished in a few steps.

How to boot macOS Big Sur on an M1 Mac from an external bootable drive

Cannot Boot From Hard Drive

  1. With the Mac powered off, connect the external bootable drive to the Thunderbolt 3 port.
  2. Turn the Mac back on with a long press of the power button, holding until the screen shows startup options.
  3. Select the bootable external drive.
  4. Your Mac will then boot from the external drive instead of the internal storage.

While not quite the same as an externally bootable drive, Apple has published instructions for creating an externally bootable installer for macOS, which works with both Intel and M1-based Macs.

You could also reinstall macOS to the internal drive instead of the external drive using the second method by selecting the internal drive, a method we have covered previously. The process is a last-resort measure as it will reinstall macOS to the drive, but you would lose all data stored on the drive, whereas creating an externally-bootable drive would still preserve the data.

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by Jenefey AaronUpdated on 2021-06-16 / Update for OS X

You may need to boot up your Mac using an external drive or boot volume once in a while, rather than using a start up disk. Booting with an external disk has a lot of significance. Maybe you want to troubleshoot some problems, repair the disk, do partitions, format the entire disk, update, and install OS X etc. All these are executed perfectly when you use an external boot volume to boot up your Mac. In this article, we are here with the detailed step by step guide on how to boot Mac from external hard drive easily. So, let's get started…

How to Recover Data from External Hard Drive in 3 Ways?

Part 1: How to Boot Mac from USB Drive/CD/DVD

Actually, it is possible to boot Mac from external drive or a hard drive, but there are a few specific requirements needed for your Mac to become eligible for that process.

  • First, you have to have an Intel-Based Mac.
  • Second, the CD or DVD you are using to boot must contain Apple’s Super Drive or if you are using a USB drive then it should be formatted with GUID Partition, and you are also required to install OS X installer. Apple is against booting Mac from an external storage device, because you may install an older version of OS X than the one you were using.

Boot from CD or DVD:

If you want to boot your MacBook/Air/Pro/iMac from an optical media like CD or DVD you need to follow the steps below:

Boot From External Dvd Drive Mac

1. Open your Mac or restart the device if you were already using it.

2. When the startup music is playing press and hold the “C” key from the keyboard.

3. This will start the OS X installer from the CD/DVD on your Mac.

So, it is not too complicated to Mac boot from CD/DVD. You can easily burn a bootable image of OS X on a DVD by using Disk Utility.

Boot from External USB:

Using your USB drive to boot Mac is not as simple as you think. You need to prepare your USB drive beforehand for this specific purpose. You have to format the USB drive and insert the proper Operating System, which is OS X.

1. Turn on your Mac.

2. As soon as the startup music begins you need to press and keep holding the 'Option' key.

3. After that release that key, the Startup manager will be launched.

4. Startup Manager will begin scanning your device and you will be provided with a list of devices that are connected to your Mac.

5. Now, select the drive you want to use with your mouse.

6. Finally, press 'Return' key on the selected option to boot Mac.

This way you can boot your Mac with an external USB drive, but the most critical part is to prepare the USB drive. If you have multiple USB drives connected, then the Startup Manager shall list the drives with the bootable OS. So, this is how to boot Mac from USB drive.

Part 2: Common Problems and Fixes When Boot Mac from External Drive

You may face several issues during MacBook Pro Boot from USB or any external drive. So, a few FAQs are mentioned below which may help you when you are facing any difficulties.

  • 1. Have you tried connecting to a different USB port?
  • If you are unable to startup the installer after connecting the USB drive to your Mac, then first you should try connecting it to a different USB port. It may fix the problem.

  • 2. Have you formatted the USB drive with GUID partition?
  • If you are having problems with your USB storage device then you need to make sure that if you have properly formatted the drive with GUID partition. You have to do it properly otherwise the Intel-Based Mac won't start.

  • 3. Is your Mac shutting down after connecting the disk?
  • Actually, the MacBook contains a preventive measure and because of that computer shuts down automatically when a damaged USB drive is connected or if the USB port itself is damaged.

  • 4. Is your Disk needs repair?
  • If your Mac fails to boot from an external drive even though you have properly installed the OS X installer, then maybe your disk is damaged. You should open Disk Utility and ask permission to repair disk.

  • 5. Have you connected the USB drive properly?
  • There are two types of Apple keyboards, Wired and Wireless. There are also some keyboards with inbuilt USB ports but they may not have enough power to run the drive.

So, this is how to startup Mac from external drive. Follow the frequently asked questions to clear any doubts that you have while booting from external hard drive Mac.

Create Bootable Os X Usb On Windows

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