Safety in Backups

Here's a lengthy report from John Carter, but it's worth your time to read it.  From here on we're quoting John. 

Scenario: You've had your Mac now for 2+ years and everything seems to be running just fine. Suddenly, without warning, you can no longer boot up the system. What happened?

The hard drive just failed!!! Well, maybe something else, but let's say it was the hard drive.

What's the best recovery method? Well, to get you started right away it would be nice if you could simply continue to use your computer until you have the time and the money to get it fixed. That can be done if you have an external drive ready to plug in and boot from.

To prepare an external drive as an alternate boot source, you need an external hard drive of the same size as your internal hard drive (use Get Info on Macintosh HD and read the Capacity). The external hard drive can have any configuration of inputs; USB 2.0 is the most common, but Firewire 400 is better, and Firewire 800 is best. When USB 3.0 is available for the Mac, that is even better. However, the price increases with each better interface, so it is quite all right to use USB 2.0 for this emergency external hard drive. Don't worry if the external drive doesn't say it is for a Mac, because it will be reformatted when you create the boot drive next.

The next thing you need is SuperDuper! for Mac. Download it from here. You can use SuperDuper! for free as long as you don't attempt to use any of the advanced features, and you won't need them for creating an emergency boot drive.

When the USB external drive is connected, launch SuperDuper!.

 (Double click to enlarge the illustration.) 
Notice in the image above that the Copy field points to the Macintosh HD (your internal drive) and in the To field you click on the double arrow and select the external drive you plugged in.

Next comes the easy part. Click on "Copy Now," take the defaults for any prompts that follow, and go to bed. In the morning, you may discover an error message on your screen that says, "You have been logged out..." blah, blah, blah. Just ignore that message. What you need to know at this point is that you should now be running off of the external drive and NOT off of the internal drive. This is simply a confirmation that creating the external boot drive actually worked!

To get back to working off of the internal drive, open System Preferences and click on "Startup Disk." The external drive you are running on should be highlighted. If it isn't, something went wrong with the copy process. (I shouldn't scare you like that. But if this did happen, you should still be running off of the internal drive and you should then call for help to figure out what to do next.) To boot up off the Internal drive, click on the icon identifying "Mac OS X < ... > on Macintosh HD," then click on the Restart button. When the Mac starts up again, eject the external hard drive and put it away for emergencies.

You're not done. If you ever do need to use the external boot drive, remember that the only applications, updates, and files in it are the ones at the time you created the boot drive. Maybe once in a while you might want to do this all over again? Not really. If you were also smart enough to maintain a Time Machine backup, you only need to update the boot drive from the latest Time Machine backup entry. Now you're back in business right where you left off, and maybe with just a few lost minutes (the Time Machine performs a backup every half hour). When time and money permit, take your Mac to your repair center and have them install a new drive. Be sure to also give them the boot drive you created so they can restore it to the new internal drive.

Remember, failure to protect your work with adequate backups is a down payment on future upsets.

When you are ready to purchase a suitable boot drive, do a Google/Yahoo search on the Internet for "external hard drivegb" (fill in the size - without the < and >) and consider one of the compact (thin) drives from Seagate, Iomega, Western Digital, or LaCie - because small is cute.


A recommended external drive to use with Time Machine depends on how much of your internal drive is being used and how much you expect to fill it in the next year or two (before it crashes). The size should be at least three times larger than what you expect to be using in your internal drive. Let me explain why. The larger it is, the farther back in time you can go to retrieve a lost file. For example, a 1.5TB drive used to backup a 500GB internal drive that contains 300GB of data will store backups for about the last three or four months. If your internal drive is 500GB and you're using less than 100GB, then a 500GB external drive might be adequate for short-term recovery. However, it is highly recommended that the drive has a Firewire 800 input so that performing a backup is performed in the quickest time possible. That being said, a USB 2.0 drive will work if saving an extra $50 means more. At least do a search for "external hard drive firewire 800" and look for bargains.

There's a bright side to every catastrophe. If your hard drive does fail, it could be a good excuse to buy the newest computer. You really don't need to hang onto years of photos and email anyway, right?