FileVault and Backups

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Mac OS X's FileVault feature optionally encrypts the entire contents of your home folder, so that your files are protected from prying eyes and thieves. It accomplishes this behind the scenes by storing your home folder in an encrypted disk image. Using File-Vault may complicate backups.
If you ask your backup software to archive the entire disk image, it will be unable to perform incremental archives of your home folder, instead making a complete copy of the image each time it runs. This is because, from the point of view of the backup software, your entire home folder is a single fileso any change to the data in your home folder, no matter how small, must result in that entire FileVault disk image being copied again.
You can work around this problem by instructing your software to ignore the FileVault disk image and instead look only at the files stored within it; you must then make sure your FileVault-protected home folder is unlocked and mounted when your backup software runs. However, if you have backups running when you are not at your machine, an unlocked FileVault disk image can jeopardize the security of your files. For this reason, if you must use FileVault, you should schedule backups to begin when you are physically present.

But my recommendation, instead, is to avoid using FileVault in the first place. Backup concerns aside, the way FileVault stores your data in day-to-day use makes it extremely vulnerable to corruption; theoretically, even a tiny amount of damage could render your entire home folder unusable.
Finally, start the backup. Often this is just a matter of clicking a "Backup" button.
After testing your archive, you can repeat this procedure to set up archives to additional hard drives or other media.

Test Your Archive

When the backup is complete, test it by choosing a few random files or folders from the archive to restore. If your backup software has a Restore feature, use it; if not, select your former destination volume as the source. To test your archive, follow these steps:

1. Restore to a different location: You can usually restore files either to their original locations or to another location of your choice. For this test, restore your selected files to a different locationsay, your Desktop folder or another spot where you can find them easily.


2. Check the restored files: Compare the restored files to the originals using the Finder's File > Get Info command. Each pair of files should match exactly: same name, size, icon, creation date, and modification date. If the files were not copied to your selected destination or they are not identical, then either your backup software or its user made an error! Check your software's documentation, and if necessary contact the developer's technical support department for assistance.

3. Try an in-place restoration: Temporarily move one of the original files you backed up to a different location (again, the Desktop folder works well for this), then use your application's Restore feature to restore the file to its original location.

4. Check the restored files: Again, check each file carefully to make sure it is correct.

If the files are correct regardless of the location to which you restored them, your archive is working properly

Tip
Although your initial test of a backup may succeed, it's important to test backups regularly to confirm that the archives are still intact, and that all the required files are being updated as they should be. If you're unaware of an error that has been preventing your backups from running properly for the past few months, the consequences could be severe. Get in the habit of doing a test restoration every time you change your car's oil or test the batteries in your smoke detector. By the way, if you haven't changed your oil or tested the batteries in your smoke detector recently... now might be a good time.

Automate Your Backups

Now that you have successfully performed and tested both a duplicate and an archive, it's time for the last important step: scheduling these backups to occur automatically.
Any backup software worth its salt will make it easy to put a given backup procedure on a simple, recurring schedulee.g., Daily Archive every night at 11:00 p.m., Weekly Duplicate every Sunday morning at 6:00 a.m.
When choosing times and days for your backups to run, keep in mind these considerations:

• Will the destination media be ready? If not, will you be available to insert or enable it?
• Do you need to supply a passwordfor the backup software itself, or to mount a network volume? If you cannot store such passwords in your Keychain, or do not wish to do so, be sure the backups run when you're present to enter the passwords.
• Will the backup slow down your computer? If so, think about scheduling it for a time when you're not busy.

Regardless of your software, begin by scheduling your archives, which will probably run every day. Then schedule duplicates, choosing a time of day well before (or after) your scheduled archive run to avoid conflicts between the two schedules. Repeat as necessary for each media set you will be using.
Be sure to make a note of your duplication schedule in your favorite calendar application or on a paper calendar so that you will know when to swap media for off-site storage. For example, if you do a weekly duplicate on Sunday, you might create a recurring reminder to swap media every Monday morning before work.

Power Management and Backups

Although this may seem self-evident, a scheduled backup will not run unless your computer is already turned on and awake at the scheduled time. Some people leave their computers running all the time, perhaps setting the display to dim or the hard drive to spin down after a certain amount of idle time to save energy. However, if you normally turn off your computer or put it to sleep when you're done using itor if you have it set to go to sleep automaticallyyou may run into problems with scheduled backups. In most cases, these problems are easily solved with a bit of foresight.
Power management on a Mac is controlled using the Energy Saver pane of System Preferences. If you click the Schedule tab, you'll see a checkbox labeled "Start Up the Computer." What it does not tell you is that this setting will also wake up a computer at the scheduled time if it's on but asleep. If you select that checkbox and enter the days and times corresponding to your backup schedule (say, Every Day at 2:00 AM), the machine will turn itself on (or wake itself up) at the appropriate times. However, a few words of caution:

• Be sure to select times at least 5 minutes before your backups are scheduled, to allow the computer time to start up completely.
• If you configured your Mac to request your password when you turn it on or wake it up, the computer may get stuck at the Log In screen when you're not there. To turn off the password prompts, first go to the Security pane of System Preferences and deselect the checkboxes labeled "Require password to wake this computer from sleep or screen saver" and "Disable automatic login." Then go to the Accounts pane and click the Login Options icon near the bottom on the left. Select "Automatically Log In As," choose your user name from the pop-up menu, and enter your password when prompted.
• You can also use the Schedule pane of Energy Saver Preferences to turn off your computer (or put it to sleep) after completing a backup. If you do this, be sure to allow plenty of time; full backups sometimes take hours.
• After setting your backups on a schedule, check them periodically to make sure they are running as you expect. Some backup software provides logs for this purposeor you can look at the files on the backup media and confirm that they are as recent as they should be.

Mind Your Media

So you've got your carefully labeled hard drives, DVDs, or other media with freshly recorded data. Now what?
Taking care of your media is just as important as making proper backups in the first place. If the media is lost or damaged, it does you no good. So I want to say a few words about handling, storing, and caring for backup media.
Whether you use hard drives, optical discs, or another type of media, the same general rules apply: store them in a cool, dry place away from significant sources of light, static electricity, vibration, and other hazards (such as inquisitive pets or children). All this may seem obvious, but it pays to remember that you're doing backups in the first place because your data is valuableperhaps even irreplaceable. So treat your media with care.

Note
For extra safety, store your media in a container that's rated fireproof for media.

Recycling vs. Long-Term Archives

If you use hard drives for backups, sooner or later they will fill up. (Whether this takes a few months or a few years depends on the rate at which you accumulate new data and the size of your backup disks.) And if you use lower-capacity removable media, sooner or later you will have a stack so large it threatens to collapse under its own weight. When this happens, you have two options: buy completely new media and start over, or recycle.By "recycle" I don't mean throw your backups in a blue binI mean erase the media and reuse it for a new set of backups.
One argument for starting fresh is that new media is virtually always more reliable than old media. Another is that you can save your old media as a long-term archive, in case you need to see what was on your computer a few years ago. On the other hand, recycling media saves money, not to mention physical storage space. And most people have little need for backups stretching back more than a couple of years.
The cost of buying a new stack of DVD-R discs is, of course, much lower than the cost of buying new hard drives. In addition, as I mentioned earlier, hard drives make a poor choice for long-term storage (though an older hard drive that you wouldn't trust for backups may be fine for casual, non-critical uses). So, if you use hard disks to store your backups, you should recycle instead of replace. However, remember that hard drives don't last forevereven if they're just sitting on a shelf, your data will deteriorate over time. A reasonable compromise may be to recycle your hard drives once a year or so for 3 or 4 years, and then replace it. If, when it comes time to erase your drives, you still wish to maintain a copy of the old data, use your backup software to duplicate your archives onto a stack of DVDs first.

Recycle Before Full

For archive backups, you may wish to recycle your media on a regular basis, before it fills up. By performing periodic full backupsinstead of relying indefinitely on incremental additions since a single full backup long agoyou reduce the risk of data loss due to file corruption or misbehaving backup software. How often you recycle your media is up to you, but in general I'd suggest recycling no less often than every 6 months.
Do, however, be aware that when you recycle media, you lose all the archived files stored since you started that particular cycle. If this makes you nervous, you might consider copying the archive to a set of DVDs before erasing it. In addition, if you recycle more than one set of media (for example, two or three hard drives), stagger themdo one, wait a week or two, then do the next one, and so on. That way, if you suddenly discover that you've erased the archive containing an old file you need, you'll still have a chance to recover it easily from another set of backup media.

Tip

Be careful when erasing a hard disk that contains months or years of backupsespecially if you chose not to copy its data onto optical media. For safety, erase just one disk at a time, then perform (and test) regular backups for 1 or 2 weeks before erasing the next disk. If you erase all your backups at once, you're inviting trouble.

Off-Site Storage

Raise your right hand, place your left hand on the nearest sacred text (such as The Macintosh Bible), and repeat after me:
I hereby solemnly swear that henceforth, I will at all times maintain a recent, complete set of backup media off-site.
Good. Now I'm going to tell you why you just made such a promise and how to keep it.
No matter how diligently you back up, if something happens to your backup media, you're in trouble. Now, it is safer to keep your backups on an external volume than on, say, another partition of your internal hard disk. But as long as the media on which your backup is stored is physically located near your computer, your data is unsafe. Consider for a moment the range of events that could wipe out both your internal hard drive and any backups in the same area at the same time: fire, flood, earthquake, hurricane, tornado, burglary, destruction by rambunctious children or pets, wayward meteorites. These things all seem so unlikely until they happen to you. Insurance may enable you to replace your hardware and software, but not your data. So please take seriously my advice to keep at least one set of backups, by which I mean in a different building.
The best approach is to rotate multiple sets of backup media, so that you always have one near your computer and another stored safely somewhere else. Periodically (say, once a week), bring the off-site media back, adding it to your normal backup routine so that it can be updatedand take your most recent local backup off-site.

Tip
When it's time to replace a hard drive completely, you may consider giving away or selling your old drive. Before doing so, be sure to securely erase it so that its new owner cannot use a file recovery program to retrieve all your data! Merely dragging files to the Trash will not erase the data in such a way that it cannot be recovered. Even the default Erase feature in Disk Utility won't do the trick. Instead, use a tool that can overwrite the entire disk (including free space, not just particular files) multiple times with random ones and zeroes. Clicking the Options button in Disk Utility's Erase pane provides two ways to zero the data. Other examples of products that include this capability are:

• Shredder (www.dekorte.com/Software/OSX/Shredder/; $5)
• Trash X (www.northernsoftworks.com/; $9)
• ShredIt X (www.mireth.com/; $20)
• SafeShred Pro (www.codetek.com/; $25)
• SPX (http://rixstep.com/4/0/spx/; $39)
• TechTool Pro (www.micromat.com/; $100)

Although you can use this process with just two sets of media, having three makes it more convenient. At any given time, you'll have one set (A) in use, your next-most-recent set (B) on site, and your oldest set (C) off-site. When you rotate the media, you bring your oldest set (C) back on site and make it active, taking what has now become the oldest set (B) off-siteand so on. For maximum safety, if you use only two sets, don't bring your off-site backup media back to your home or office until after you've taken another set away; those few hours when all your media is in one place could be the time when disaster strikes.
You may be wondering where exactly "off-site" could be in your case. Here are some suggestions:

• Your place of work
• A neighbor's or relative's home
• A storage unit

Don't keep an off-site backup in your car, which is if anything more susceptible to damage or theft than your home. Heat and cold extremes in your car can also hasten data corruption. If you want as much security as possible with a trade-off of less convenience, keep it in a safe deposit box at your local bank.
Warning! Because hard disk-based duplicates are, by definition, unencrypted, storing them off-site presents a significant security risk: anyone who obtains the drive also has complete access to your data. Here are some ways of reducing that risk:

• Store the drive in a safe deposit box.
• Keep all your important data on the drive encrypted within a disk imageperhaps using a utility such as PGPDisk.
• Instead of storing the duplicate directly onto a hard disk, put it on an encrypted disk image that's stored on the hard disk. This will require extra steps when it comes time for restoring, but it's much more secure.
• Keep (encrypted) archives and (unencrypted) duplicates on separate media, and store only the archives off-site.