When you download and install Mac OSX Lion, the installer creates a small invisible partition on your startup hard drive containing recovery options in the event you encounter system problems. Since there’s no physical DVD containing the Lion operating system, you need a “boot disk” in case you ever need to reinstall Lion or run Disk Utility in an attempt to repair an ailing hard drive.

But what happens if your startup hard drive develops serious physical problems? It’s possible that your recovery partition itself could be damaged, rendering it unusable. What do you do in that situation? Fortunately, Apple just released a solution: an application called the Lion Recovery Disk Assistant. Basically you download and run this utility to create a startup disk on an external USB drive. Here’s how to create it:

  1. Download the free Lion Recovery Disk Assistant application from:
    http://support.apple.com/kb/DL1433.
    It’s a small 1MB download.
  2. Drag the application from the installation disk image onto your Mac’s hard drive. Then open it by double-clicking.
  3. You’ll be asked to locate a USB drive with at least 1GB of free space. Be advised: The application will erase everything on this USB drive.

I installed it on a 4GB SD card inserted into a USB card reader. The installation was quick and easy.

How to use the Recovery Drive

Restart your Mac while holding the option key down and with the USB drive connected. You should see the recover volume appear.

Click the appropriate Recovery HD icon. You’ll be taken to a menu of recovery choices:

  • Restore From Time Machine Backup
  • Reinstall Mac OS X
  • Get Help Online
  • Disk Utility (to try to repair the hard drive)
Make your selection and try to recover from your system problem. I almost always start with Disk Utility and a “repair” option.

There’s also a Utility menu with more technical diagnostic and recovery options:

  • Firmware Password Utility
  • Network Utility
  • Terminal

Important Note: You should create a recovery drive BEFORE you encounter problems — not after when it’s too late! In other words, do it today.