You can turn it on again after using Target Disk Mode. Before using Target Disk Mode, you can boot the Mac normally, open the System Preferences window, select Security & Privacy, select FileVault, and temporarily turn it off. FileVault Disabled: Macs now enable FileVault encryption by default, which will prevent you from accessing FileVault-encrypted home directories over Target Disk Mode.If one Mac has a Thunderbolt port and the other Mac has a Firewire port, you’ll need a Thunderbolt-to-Firewire adapter cable. A Firewire or Thunderbolt Cable: You’ll need either a Firewire cable or a Thunderbolt cable for this.Each Mac needs either a Thunderbolt port or a Firewire port. Two Macs: Target Disk Mode works with Macs, so you’ll need two Macs for this.You can now quit Terminal and eject the volume.RELATED: How to Encrypt Your Mac's System Drive, Removable Devices, and Individual Filesīefore entering Target Disk Mode, you’ll need a few things: When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Catalina.Terminal shows the progress as the bootable installer is created. When prompted, type Y to confirm that you want to erase the volume, then press Return.Terminal doesn't show any characters as you type your password. When prompted, type your administrator password and press Return again.If it has a different name, replace MyVolume in these commands with the name of your volume. These assume that the installer is still in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. Type or paste one of the following commands in Terminal.

Open Terminal, which is in the Utilities folder of your Applications folder.

Make sure that it has at least 12GB of available storage and is formatted as Mac OS Extended.

Connect the USB flash drive or other volume that you're using for the bootable installer.

Use the 'createinstallmedia' command in Terminal You will create the bootable installer from this app, not from the disk image or. It installs an app named Install OS X El Capitan into your Applications folder.

On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg.

Install os x el capitan target disk