6.2 Where to Back Up?

Now that you have an idea of what you should back up and how often, the next question is to what location should you back up that data?

If you are using the Backup application, there are two options as to where you can back up your data:

• Your iDisk

• CDs or DVDs (depending on whether your Mac has a Combo or SuperDrive, respectively)

• USB and FireWire drives , including your iPod (which connects to your Mac via FireWire)

• Networked file shares such as a remote server or even to another Mac that has File Sharing enabled

Ah, decisions, decisions...but let's look at this in terms of data storage capacity, frequency of backups , and the cost factor involved.

Backup may not play well with some third-party CD/DVD burners. To see whether your device is supported, go to http://www.apple.com/macosx/upgrade/storage.html.

6.2.1 The Price of Backing Up

With a basic .Mac membership, you get 100 MB of storage space. This can be used for anything you desire ”including for backups ”but keep in mind that the files you use for your Mac.com HomePage (see Chapter 7) are stored on your iDisk in the Sites folder, QuickTime movies are stored in the Movies folder, and the photos you use to create slideshows with iPhoto are stored in the Pictures directory.

If your Mac has a Combo or SuperDrive, you can back up your data on CDs or DVDs, respectively. Depending on which you have, you can back up anywhere from 750 MB to 4.5 GB. CD-R's are fairly inexpensive these days, and they make a cheap solution for quick, throwaway backups. CD-RWs cost a bit more, but you can reuse the CDs a few hundred times before having to toss them. If you plan to use CD-RW discs for doing backups, you should probably pick up 20 or 30 of them so you can have one set of discs for each week. DVD-R's are probably twice the cost of CD-RWs, but they hold far much more data ”up to 4.5 GB.

If you look at the cost per megabyte (CPM) for storage media and compare that with the cost of purchasing additional space for your iDisk (Table 6-1), you'll quickly see the cost savings.

Table 6-1. Cost per megabyte (CPM) for storage media

Media type	Maximum storage capacity	Retail cost	CPM
iDisk	100 MB	$100/year	$1.00
	200 MB	$160/year	$1.25
	300 MB	$200/year	$1.50
	500 MB	$280/year	$1.79
	1 GB	$450/year	$2.22
CD-R	700 MB	$0.40/disc	$0.00057
CD-RW	700 MB	$0.80/disc	$0.0011
DVD-R	4.5 GB	$2.00/disc	$0.00044

As you can see from Table 6-1, unless your Mac has a SuperDrive for burning DVDs, CD-R's are probably the most inexpensive way to go, particularly if you can find the discs on sale somewhere. You can typically find a 50-disc spindle of CD-R's for around $20 (or $0.40 each), while a 50-disc spindle of CD-RW's will run around $60 (or $0.80 each). ^[2] Since CD-RWs can be erased and written again many times, they're more cost-effective in the long run (and you'll have less waste going to the landfill every month, too).

^[2] Disc spindles don't include jewel cases or sleeves for the CDs. If you want to store your CDs in jewel cases, you can purchase the writeable CDs with the jewel cases, but they might cost a little more.

6.2.2 So to What Location Do I Back Up?

Chances are that you will overshoot the 100 MB limit if you try to back up everything in your Home directory to your iDisk. Even if you upgrade your iDisk's capacity to 1 GB, you could be pushing it. So what should you do?

I actually use a three-step backup method:

• I backup the bare bones to my iDisk daily. By "bare bones," I mean that I'm mostly backing up my preferences, my Keychain file, and some of the default backup packages.

• Every night, I back up my Documents folder and my email from Mail.app to an external FireWire drive.

• Once a week, I back up my entire system to a set of CDs (if my PowerBook G4 had a SuperDrive, I would back up to DVDs).

While this might sound like overkill, you should never take your data for granted. Give some thought to your backups, and find the time to work them into your daily or weekly routines. The only backup that takes any amount of time from me is my weekly backup of the entire system; the others are scheduled to run in the middle of the night when I should be sleeping. While it might seem like you're wasting time that you could spend watching the latest reality TV show, you'll actually be doing yourself a favor. You never know when your system is going to crash hard, and when it does, you'll be thankful that you have a backup you can restore from.

Backup works best if the drive you are backing up to is formatted as HFS+ (Mac OS Extended). While I haven't had any problems backing up to my USB key fob or to my LaCie FireWire drive, you should check to see that the filesystem you're going to back up to is formatted properly.

To do this, launch Disk Utility ( /Applications/Utilities ), click on the name of the drive in question, and then click on the Info button. The third item down should be labeled "File System"; if it says either Mac OS Extended or Mac OS Extended (Journaled) next to it, you're good to go.

Now that we've discussed the why's and where's of backing up, it's time to get rolling with it.