Thursday, July 31, 2008
Toolbox: External Storage Solutions
Smart image backup solutions for home and on the go
FOR HERE OR TO-GO?
External drives come in several flavors. The most common are the single-drive setups with up to 1 TB of storage and the dual-drive units with up to 2 TB split over the two drives in a RAID configuration. We'll talk more about RAID in just a bit. The third option, and one that's finally at a price that us mere mortals can handle, are the dedicated RAID units with multiple drives, capable of many TB of storage; they have become easier to use, too. One such unit is the Drobo, which holds up to four drives. If you need to back up multiple computers to a single device, Network-Attached Storage (NAS) devices make it easy to share drives over your network.
While you want a big drive for your master backups at home, it's also wise to back up when you're on the go. More and more photographers are carrying a laptop just for this purpose, as well as a portable drive to be sure they have multiple copies of their photos until they're safely archived at home. These little wonders pack up to 500 GB in a case that's not much bigger than your cell phone and need no external power supply—just plug it into your USB or FireWire port, and you're good to go.
PLAN FOR IT
All the storage in the world won't do you much good if a drive fails and you don't have a backup plan in place. Here, the external units really shine. Almost all the drives include a backup program, and with the storage space you'll have available, it's a simple task to set up these programs to run automatically, backing up everything you want in the background while you work or sleep. This can't be stressed enough—back it up or lose it!
Another option, mentioned earlier, is RAID. If you use one of the multidrive systems, you can set it up so that each drive is an exact copy of the other. You have only half the storage space, but you have a constant, real-time backup should one drive fail. Essentially, RAID is a way to use multiple drives to increase performance, reliability and capacity—but not all at the same time.
The most common configuration is RAID 0, which uses multiple drives to increase performance—two 1 TB drives are seen as a single 2 TB drive, but both drives can be working simultaneously through a process called "striping."
RAID 1 is more applicable to our needs as digital photographers. Those same 1 TB drives are seen as independent, and each drive is a mirror copy of the other. If one fails, the other has identical data, so nothing is lost.
The less common RAID 5 configuration requires at least three drives and provides both the speed benefits of RAID 0 and the protection of RAID 1. Three or more drives are required in RAID 5 to ensure data redundancy if one of the striped drives fails.
Along with deciding on a capacity, you need to determine the best method of connecting your drive. There are four major interfaces in external desktop drives. USB is by far the most common and works with any computer that has a USB port, which is just about every computer you're likely to use. For the portable drives, USB serves as both the connection and the power source, eliminating the need to carry a power supply. FireWire is another common option, particularly on Mac computers.
If you need to connect to a network, consider a drive that includes Ethernet. Although the access speeds with a network drive typically are slower than one connected directly to your computer, if you need to share space across several computers, this is a good solution.
The eSATA interface isn't as common—in fact you may need to get an eSATA card for your computer—but it offers the highest transfer rates of any external drive. Many of the drives covered here are available in multiple versions, including some that include USB, FireWire and eSATA, giving you the most flexibility as your computer hardware is upgraded over time.
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