Apple Has A New Way To Recover, Repair, Or Restore Lion
Therefore, however, providing the means to recover or repair a system has become a unique challenge. With Lion Recovery, the OS has a built-in Recovery HD with which you can repair a disk, run a restore from Time Machine, browse the Web (with Safari only), or completely reinstall the operating system. It’s certainly a nice feature, but this option is not helpful in the slightest if the hard drive itself is going south.
Should the Recovery HD fail for whatever reason, you can also use Lion Internet Recovery, which connects to Apple’s servers remotely even without the system booted. Once your computer is connected and a Recovery HD is established, you can do whatever you would normally be able to do from the built-in Recovery HD.
There’s now a third option, Lion Recovery Disk Assistant, which allows you to create a Recovery HD on an external disk. Your external drive must have at least 1GB of space, and of course it will wipe whatever was previously on that drive unless you partition it first.
If a given system shipped with Lion installed on it, any external recovery partition you make can only be used with that computer. However, if you create the external Recovery HD on a computer that has been upgraded to Lion from Snow Leopard 10.6, you can use it on multiple machines that shipped prior to Lion’s release. You also can’t create an external recovery partition on a machine that doesn’t already have a Recovery HD. (Good news: that Recovery HD is already built in.)
Using the tool appears easy enough; according to Apple’s instructions, you simply open the Lion Recovery Disk Assistant and follow the onscreen instructions. To access the partition, hold down the Option key during startup and select it when the choice is available.
The Lion Recovery Disk Assistant fills essentially the same role that Lion Internet Recovery does in that it’s there to bail you out if the built-in Recovery HD fails or if you have a new hard drive, but you don’t need to use the Internet. You do have to keep track of a USB stick with this method, though.