- Download And Boot From A Flash Drive Mac Os
- Boot Macbook From External Drive
- Download And Boot From A Flash Drive Mac Torrent
Creating a MemTest86 bootable USB Flash drive in Linux/Mac
- Download the current Memtest86 package as a Zip file from this page.
- Unzip the file. Inside the Zip there is a 'disk image' file. For the free edition of MemTest86, this file is called, memtest86-usb.img
- Insert a USB flash drive into a USB slot. It needs to be at least 512MB in size.
Warning: The contents will be overwritten in the next steps. - Determine which device the USB drive is assigned as by opening the Terminal and typing the following command. Don't get this wrong as you don't want to overwrite the wrong drive. diskutil list
- Unmount all volumes on the USB drive by typing the following command: diskutil unmountDisk <device_name>In the example above the device name is /dev/disk2
- As the root user, use the 'dd' command to write the image to the USB drive. For example, sudo dd if=memtest86-usb.img of=<device_name>where the <device_name> is the device the USB key is assigned to. Use the base device (ie. /dev/disk2) not a partition designation (ie. /dev/disk2s1).
Warning: all data on the USB key will be lost.
3rd warning! Make sure that the device used in the dd command above is correct. The consequence of picking the wrong drive are potentially disastrous. Total and compete data loss from your hard drive, if you overwrite the wrong drive. - When finished, Reboot your On a Mac, you need to hold down the ALT / Option key on the Mac keyboard while powering on the machine to boot from USB.
On newer Macs (from 201 with the Apple T2 Security Chip, you may need to change the SecureBoot settings for MemTest86 to boot. Please see the following page for instructions: https://support.apple.com/en-us/HT208330
Set your bootable USB as your startup disk for the next boot in “Apple Menu - System Preferences - Startup Disk,” then click “Restart” to reboot your Mac. Your Mac will reboot from the USB instead of your default startup disk. Alternatively, you can also use the Startup Manager to select your boot drive when you start macOS. Plug your external drive into your Mac. Power up (or restart) your Mac. Press down on the Option key while the Mac boots. After a few moments, your Mac should display the Startup Manager, which.
These advanced steps are primarily for system administrators and others who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.
What you need to create a bootable installer
- A USB flash drive or other secondary volume, formatted as Mac OS Extended, with at least 12GB of available storage
- A downloaded installer for macOS Big Sur, Catalina, Mojave, High Sierra, or El Capitan
Download macOS
- Download: macOS Big Sur, macOS Catalina, macOS Mojave, or macOS High Sierra
These download to your Applications folder as an app named Install macOS [version name]. If the installer opens after downloading, quit it without continuing installation. To get the correct installer, download from a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. Enterprise administrators, please download from Apple, not a locally hosted software-update server. - Download: OS X El Capitan
This downloads as a disk image named InstallMacOSX.dmg. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder. You will create the bootable installer from this app, not from the disk image or .pkg installer.
Use the 'createinstallmedia' command in Terminal
- Connect the USB flash drive or other volume that you're using for the bootable installer.
- Open Terminal, which is in the Utilities folder of your Applications folder.
- Type or paste one of the following commands in Terminal. These assume that the installer is in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace
MyVolume
in these commands with the name of your volume.
Big Sur:*
Catalina:*
Mojave:*
High Sierra:*
El Capitan:
* If your Mac is using macOS Sierra or earlier, include the
--applicationpath
argument and installer path, similar to the way this is done in the command for El Capitan.After typing the command:
- Press Return to enter the command.
- When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
- When prompted, type
Y
to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the volume is erased. - After the volume is erased, you may see an alert that Terminal would like to access files on a removable volume. Click OK to allow the copy to proceed.
- When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Big Sur. You can now quit Terminal and eject the volume.
Use the bootable installer
Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:
Apple silicon
- Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
- Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes and a gear icon labled Options.
- Select the volume containing the bootable installer, then click Continue.
- When the macOS installer opens, follow the onscreen instructions.
Intel processor
- Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
- Press and hold the Option (Alt) ⌥ key immediately after turning on or restarting your Mac.
- Release the Option key when you see a dark screen showing your bootable volumes.
- Select the volume containing the bootable installer. Then click the up arrow or press Return.
If you can't start up from the bootable installer, make sure that the External Boot setting in Startup Security Utility is set to allow booting from external media. - Choose your language, if prompted.
- Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.
Download And Boot From A Flash Drive Mac Os
Learn more
For more information about the
createinstallmedia
command and the arguments that you can use with it, make sure that the macOS installer is in your Applications folder, then enter the appropriate path in Terminal:Boot Macbook From External Drive
- Big Sur: /Applications/Install macOS Big Sur.app/Contents/Resources/createinstallmedia
- Catalina: /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia
- Mojave: /Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia
- High Sierra: /Applications/Install macOS High Sierra.app/Contents/Resources/createinstallmedia
- El Capitan: /Applications/Install OS X El Capitan.app/Contents/Resources/createinstallmedia
Download And Boot From A Flash Drive Mac Torrent
Writing software, free download for mac full version. A bootable installer doesn't download macOS from the internet, but it does require an internet connection to get firmware and other information specific to the Mac model.