Dr. Mac's Guide to Backing Up Your Mac
By Bob "Dr. Mac" LeVitus
Chapter 3: Backup Hardware and Media
You'll need to backup to some type of media-optical media such as a CD-R, CD-RW, DVD-R, or DVD-RW, or to a magneto-optical cartridge, tape, or external hard drive. So you may need to purchase an additional piece of hardware. Bear in mind that the initial cost of your hardware device is only the tip of the iceberg. In addition to the hardware you will also need to purchase enough media-optical discs, disks, tapes, or cartridges-to back up your hard disk at least 3 times. And if you follow Immutable Rule #3 in the previous chapter, you know that you'll eventually need even more media, so keep that in mind.
How much media will I need?
How do you know how much media you're going to need? That's easy. Click the hard disk's icon and choose Get Info from the File menu, or use the keyboard shortcut Command-I, which brings up the Info window as shown in Figure 3-1.
Figure 3-1: The Get Info window for my startup disk, Boots.
My hard disk named "Boots" has a capacity of 148.93GB, of which 77.51GB is currently being used. So if I want to back up the entire thing, I'll need enough media to back up roughly 80GB at least three times.
As I mentioned previously, most backup programs compress your files as they back them up. Most of them use less-efficient software compression but many tape drives use faster, more efficient hardware compression. Compression can reduce the size of your files anywhere from 0% to 70% depending upon what kind of files they are. (JPEG graphic files, for example, won't compress as much as Microsoft Word files.)
The bottom line is that if you use backup software, your backed up files will almost always take up less space than the number you see in the Get Info window for your hard drive.
So consider the size of your hard disk and how much important stuff is on it. Then, make sure you can afford not only a hardware device if necessary, but also enough media for 6 or more backup sets.
You'll find cost estimates for backing up various amounts of data to the types of media discussed below at the end of this chapter. You probably ought to read everything in this chapter before you even consider shopping for new hardware.
CD-R (and CD-RW)
CD-R (CD-Recordable) and CD-RW (CD-Rewritable) are two similar technologies that basically "burn" your data onto CD-ROM discs. CD-R can only do this and nothing else; CD-RW can record regular CD-Rs, but it can also read and write to special (and slightly more expensive) CD-RW discs, which unlike CD-Rs, can be erased and rewritten numerous (1,000 is most people's best guess) times.
CD-R discs you create can be read in most standard CD-ROM drives; the more expensive CD-RW discs can be read only by other CD-RW drives as well as some CD-ROM drives.
You can also use a CD-R device to create music CDs that you can play in your portable or car CD player. (iTunes makes this a snap.)
If you try to burn an Audio CD onto a CD-RW disc it may or may not work in your audio CD player. An Audio CD burned on CD-R media, on the other hand, should work in almost any audio CD player.
Although the drives and media are the least expensive, CD-R and CD-RW discs only hold 650 to 700MB of data. So even though this may appear to be an economical system for backing up, if you have more than 650 MB of data you're going to have to do some disc swapping during some of your backups. And if you have a lot more data (which is likely), you'll need a LOT of CD-R or CD-RW discs to complete all of your backups.
A CD-R or CD-RW drive is probably just right for a Plan A user, but due to the relatively small capacity per disc-700MB tops-CD technology isn't going to cut it for a Plan B or Plan C user. (See Chapter 2 for more on plans A, B, and C.)
Not all CD-R and CD-RW media is created equal. For added reliability, make sure you get a brand of media recommended by the manufacturer of your burner. Bulk, cheap CD-R media can be very flaky.
Also, if you're going to do incremental backups on a CD-R, your backup software must support the burner. EMC/Dantz (maker of Retrospect) offers a list of compatible CD-R/CD-RW burners on their Web site. Without this compatibility you can only burn a disc in one session; with compatibility you can add to a CD-R disc in multiple backup sessions, a feature you almost certainly want. So if you're shopping for a third-party CD-R/CD-RW burner, make sure your backup software supports it properly.
CD-R/CD-RW at a glance:
- Media capacity: 650MB/700MB.
- Approximate hardware cost: $50 and up.
- Approximate media cost: $0.18 per disc and up.
DVD-R (DVD-Recordable) and DVD-RW (DVD-Rewritable) are two similar technologies that basically "burn" your data onto DVD-R or DVD-RW discs. DVD-R can only do this and nothing else; DVD-RW can record regular DVD-R discs, but it can also read and write to special (and slightly more expensive) DVD-RW discs, which unlike DVD-Rs, can be erased and rewritten numerous (1,000 is most people's best guess) times.
DVD-R discs you create can be read in most standard DVD-ROM drives; the more expensive DVD-RW discs can be read only by other DVD-RW drives as well as some DVD-R drives.
You can also use a DVD-R device to create video DVDs that you can show on almost any standard DVD player. (iDVD makes this a snap.)
DVD-R/RW discs come in two sizes-4.7GB and 8.5GB. Older DVD-R/DVD-RW devices are limited to the smaller discs but new Macs come with SuperDrives (see below) capable of burning both types.
DVD-R/RW drives and media have become quite inexpensive, but backing up to a DVD-R or DVD-RW disc can take an hour or more per disc. Can you say "S-L-O-W?" So a DVD-R or DVD-RW drive is probably just right for a Plan A user. A Plan B or Plan C user might be able to get by with DVD-R backups in a pinch but that means he or she will have to be present during backups to swap discs, which may be unacceptable. (See Chapter 2 for more on plans A, B, and C.)
Not all DVD-R and DVD-RW media is created equal. For added reliability, make sure you get a brand of media recommended by the manufacturer of your burner. Bulk, cheap DVD-R media can be very flaky.
One last thing: Some DVD-R/RW drives can burn to both DVD-R/DVD-RW (commonly referred to as DVD minus R/RW) and DVD+R/DVD+RW (commonly referred to as DVD plus R/RW discs. If your drive supports both plus and minus, feel free to purchase whichever flavor you can get the best deal on.
If you bought your Mac in the last few years it's likely you have an optical disc burner known as a "SuperDrive" built into your Mac. Most SuperDrives can burn CD-R, CD-RW, DVD-R and DVD-RW discs. Many newer SuperDrives can also burn DVD+R and DVD+RW discs.
If you're not sure what type of optical discs you can burn on your Mac, launch the Apple System Profiler application (it's in your Utilities folder) and click on Disc Burning in the Contents column as shown in Figure 3-2.
Note that my SuperDrive is capable of writing to CD-R, CD-RW, DVD-R, DVD-RW, DVD+R, and DVD+RW discs.
Also, if you're going to do incremental backups on a DVD-R, your backup software must support the burner. EMC/Dantz (maker of Retrospect) offers a list of compatible DVD-R/DVD-RW burners on its Web site. Without this compatibility you can only burn a disc in one session; with compatibility you can add to a DVD-R disc in multiple backup sessions, a feature you almost certainly want. So if you're shopping for a third-party DVD-R/DVD-RW burner, make sure your backup software supports it properly.
DVD-R/DVD-RW/DVD+RD/DVD+RW at a glance
- Media capacity: 4.7GB/8.5GB.
- Approximate hardware cost: $75 and up.
- Approximate media cost: $0.75 per disc and up.
I've had terrible luck with DVD-RW and DVD+RW (e.g. rewritable) discs. I've found that rewritable discs fail much more often than DVD-R or DVD+R discs. It might seem like a good idea to get erasable -RW or +RW discs, and thus save a few bucks, but in my experience the rewritable discs are more trouble than they're worth. I have a pile of them in my cupboard.
Magneto-Optical (MO) drives use laser technology similar to a CD-ROM drive to write your data on MO cartridges that hold 1.3GB or more of data. (Larger capacity MO drives are available but are more expensive, so for the sake of this discussion we'll limit ourselves to the 1.3/2.3GB variety.) Unlike CD-R or DVD-R (which, once you fill a CD-R or DVD-R with data, you can't write any more data to it) you can read and write to the same MO cartridge over and over again.
One of the best things about MO cartridges is that they're nearly indestructible. If you're hard on your media, and often drop stuff on a hard floor, MO may be a good choice for you. Another advantage is that backing up to an MO disc is much faster than backing up to a CD or DVD.
An MO drive is probably overkill for a Plan A user, a solid choice for a Plan B user, and too expensive (device + media) for a Plan C user. (See Chapter 2 for more on plans A, B, and C.)
An MO drive can also serve as an additional 1.3GB or 2.3GB hard disk (per cartridge) when you're not using it for backing up.
MO at a glance:
- Approximate hardware cost: $200 and up.
- Approximate media cost: $6.00 and up.
- Media capacity: 1.3GB to 2.3GB.
Tape is the holy grail of big backups. Tape drives come in many flavors-Travan and DAT (up to 20 GB per tape), AIT and DLT (up to 400GB per tape). Each uses a slightly different mechanism and requires slightly different tapes.
Tape drives are less versatile than any of the devices discussed so far. Unlike the others, a tape drive can't be used for anything but backups. In other words, you can't copy files to a tape from the Finder and you can't open a file directly from a tape. Still, if you have big backup needs, there's nothing like backing up two or three hundred gigabytes of data to the one tape. The biggest advantage of tape, for most people, is that backups can be performed "unattended" (i.e. no disc swapping) regardless of how much data needs to be backed up.
But tapes have a dark side. My experience is that tapes don't maintain their integrity over long periods of time; they last a few years at best. After a few years, tapes tend to develop errors, which can render them useless. That's because, unlike optical discs, which use lasers to record your data, tape drives use magnetic tape heads kind of like a big audiocassette recorder. Which basically means backup tapes are subject to the same idiosyncrasies as audiotapes: They deteriorate over time and are particularly sensitive to temperature extremes and magnets. This is yet another reason Rule #1 (one backup is never enough) is so important. Also, the heads on tape drives get dirty and wear out, which can damage a tape beyond redemption.
So I only recommend tape for short-term backups. In other words, if you think you are going to need data from a tape 5 years from now, I strongly recommend you also back up that data to a more permanent media such as CD, DVD, MO, or hard disk. I recommend a combination of tape and another media such as DVD, MO, or hard disk for Plan C users who want their backup data available both tomorrow and several years from tomorrow.
A tape drive is way-overkill for a Plan A user, and probably too expensive (tape drives cost more than any of the devices listed so far) for Plan B users. But they're great for the serious Plan C user who doesn't want to hang around to swap discs during large backups. (See Chapter 2 for more on plans A, B, and C.)
Tape at a glance:
- Approximate hardware cost: $200 and up.
- Approximate media cost: $2.50 and up.
- Media capacity: 4GB and up.
External hard disks are my favorite backup devices these days. They are by far the fastest devices you can backup to or restore from, and are available in sizes that insure that you won't have to hang around and swap discs. Best of all, you can make a bootable clone of your startup disk and have a backup you can plug into any other Mac on earth and thus be "back in business" in just a few minutes.
With prices today hard disks are a viable option in place of removable media. Their speed and reliability makes them ideal in circumstances where time is money. If you need to recover quickly from disk-based problems, hard disks may be your best choice. In other words, if you are a Plan C user, you should definitely consider using a hard disk for at least one of your backups.
It doesnt much matter how the hard disk connects to your Mac for this purpose: USB, USB 2, FireWire 400, FireWire 800, or even SATA. The major difference is speed. Plain old USB (USB 1, the original) will be significantly slower than any of the others; USB 2 will be about as fast as FireWire 400; FireWire 800 will be faster than USB 2 or FireWire 400; SATA (which requires an adapter card) will be the fastest. As of this writing, you cant boot a Mac with a PowerPC processor from a USB or USB 2 hard disk. Intel-based Macs can boot from a USB hard drive, but you must format the drive using GPT (GUID Partition Table) instead of the older APM (Apple Partition Map). The kicker is that Disk Utility formats internal drives on the Intel macs as GPT and external drives as APM by default, so you have to choose to format the external drive as GPT. This holds true for FireWire drives as well.
So if youre thinking of making a bootable clone as one of your backups for a PowerPC-based Mac, stick with FireWire 400 or 800. And if you choose to use a USB disk with an Intel-based Mac, remember that you must format the disk using GPT rather than APM.
For the most part I recommend buying the least-expensive type of disk your Mac supports from a reliable supplier. If USB 2 disks are on sale, get USB 2 disks (assuming your Mac supports USB 2). If FireWire is less expensive, go for that instead. It really doesnt matter much.
Hard Disks tape at a glance:
- Approximate hardware cost: $40 and up.
- Approximate media cost: $0.
- Media capacity: 20GB and up.
Media Cost Matrix
Figure 3-3 is a cost comparison of the media you'll need to perform your backups calculated for each of the devices we've just looked at. For this exercise I recommend you compare the cost of enough media to backup your data 3 times. To that end I've estimated the cost of backing up 1GB, 2GB, 5GB, 10GB, 20GB, 50GB, 100GB, 150GB, 200GB, 300GB, 500GB, 1,000GB, 2,000GB.
To use the matrix, first figure out how much data you will be backing up and multiply that number by 3. Then look at the total media cost for that number for the device you intend to use.
If you have a copy of Microsoft Excel, you can download the spreadsheet I used to create the table above. The advantage of using the Excel version is that you can change any of the numbers in blue cells to suit your needs. So, for example, if you think you can get blank DVDs cheaper than what I used in the table, you can insert that price in the spreadsheet and it will recalculate the media cost for your backups based on the lower price.
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