On the corresponding Mac the drive should appear as a mounted volume, allowing you to transfer files to or from it freely. Start up in Target Disk Mode by holding T on startup on the Mac you want to share. If either computer has macOS 11 or later, you’ll need to use a Thunderbolt cable for this. If you have an Intel-based Mac user Target Disk Mode to make your drive available to another Mac using a USB, USB-C, or Thunderbolt cable. Tim Brookes / How-To Geek T: Target Disk Mode Note: Mac models with a T2 chip may need to mount the startup volume before this will work, which instead requires booting into Recovery Mode and then following the same instructions as Apple Silicon models as described above.

After this, you can perform standard Terminal operations. Before long, you’ll see a command line prompt where you may need to authenticate with your password. Press and hold Command+S while your Mac boots to access single-user mode. Press and hold Command+Option+P+R while your Mac boots to reset it. There are all sorts of reasons to reset your NVRAM or PRAM, like if you’re having trouble getting your machine to start, starting from the wrong volume, or are simply having unexplained issues. This is only present on older Intel-based Mac models, so Apple Silicon users don’t have the option to reset it. This includes things like screen resolution, which drive to boot from, volume, and more. Non-volatile RAM (NVRAM) or parameter RAM (PRAM) stores information while your Mac is off. Tim Brookes / How-To Geek Command+Option+P+R: Reset NVRAM/PRAM You can also launch Apple Diagnostics from the internet by holding Option+D at startup, which is handy if you can’t get online. Run Apple Diagnostics to check your Mac for known issues, then cross-reference any error codes you get with Apple Support. This includes USB drives that are plugged in while your computer starts up, Windows partitions created with Boot Camp, or additional macOS installs that are stored on external drives. If you want to boot from a different partition or volume then hold Option while your Mac boots to see a list of eligible boot disks. This allows you to do things like reinstall macOS, access Disk Utility to attempt to repair any drives, execute commands using the Terminal, or restore from a Time Machine backup. To access Recovery Mode, press and hold Command+R while your Mac boots. In the Utilities section are a few more useful tools:

Disk Utility: Apple’s built-in storage utility allows you to format drives, create partitions, run First Aid, create or restore disk images, and more.Īt the top of the screen, you’ll see “Recovery” on the menu bar along with a Utilities drop-down menu.

Safari extensions and plug-ins are disabled. A nice failsafe to have if you need to search for solutions to a problem you’re fixing in Recovery Mode. This will download the required files from the internet.

Reinstall macOS: Depending on the version of macOS, you’ll see an option to reinstall or install the operating system.

Plug in your drive, select this option, and wait for the process to complete.

Restore from Time Machine: Choose this to restore your Mac’s data from a recent Time Machine backup.Once you’ve done so you’ll see a few options appear:

Once macOS has booted, you will need to select an admin user and log in to make changes. Click on it, and your computer will boot into Recovery Mode.

Next to your volumes in the startup options is a button with the “Options” label. Learn more about fixing macOS problems with Safe Mode. In safe mode, your Mac will disable all startup items, run system integrity checks, delete caches, only load system fonts, and more. Now click “Continue in Safe Mode” to start booting. To do this, click on your chosen volume (likely “Macintosh HD”), then hold the Shift key. While you’re on this screen, you can boot your Mac in safe mode.

Mac restart command line