Many of us will eventually experience that sinking feeling, a never-ending spinning beachball. Even worse, when testing reveals an error in the Volume Structures test. Making repairs to your startup disk requires starting up from a separate disk, which exactly the scenario that an eDrive or Protogo device is designed to fill. If, at this point, you have an eDrive or Protogo device, you will be well situated to get your Mac back up and running. You’ll have a life raft.

If an eDrive or Protogo device isn’t already available, you can end up caught in a catch-22. There are times when creating an eDrive or Protogo device fails because the basis for that device – your internal hard drive – is unable to copy the necessary files. So it’s especially important to be prepared and create your eDrive or Protogo device in advance of hard drive problems.

Creating an eDrive starts with the eDrive tool. Simply select the destination device (an external drive is the better option if using Mojave or later), and click create eDrive. Techtool Pro will add a new partition to the drive, and then copy the necessary components to make a valid startup disk.

Similarly, creating a Protogo device starts with the Protogo tool. After clicking Open Techtool Protogo, a separate Protogo window will open. Select the device and the profile (we recommend the Basic Profile for most cases), then click Build Techtool Protogo Device. With Protogo, the device is reformatted, making it a dedicated startup disk, rather than the separate partition with the eDrive. When finished, you have a diagnostic startup device.

Once your eDrive or Protogo device is created, your life raft is ready, and you can restart and hold the option key to choose the device as your startup disk. Once started up, Techtool Pro will launch, providing quick access to do your necessary tests or repairs.

Pro Tip: In particular, when creating Protogo device before it is needed, start with a good target device.