External Storage: When One Disk Isn’t Enough

Network Attached Storage (NAS) devices are an easy and inexpensive way to provide storage for a group of networked computers, but sometimes storage just doesn’t need to be shared. When you want to add capacity to a single system, the easiest, least expensive way to do it — and still get the performance you need — remains an external hard drive. Most such products use single drives, which limit their storage capacity (currently a maximum of 1 TB) and don’t provide any added security through data redundancy (e.g., a second drive that stores an exact copy of the first drive).

Products like Buffalo Technology‘s DriveStation Duo gets around these limitations by using a pair of drives instead of just one — every DriveStation Duo unit has two 7,200 rpm Serial ATA (SATA) hard drives inside. The $249 model we tested offered 500 GB of storage (the lowest-capacity available), but if you need more storage you can choose from three other models — 800 GB ($449), 1 TB ($499) or 1.5 TB ($999).

Features
Your connect the DriveStation Duo to a PC to either a USB 2.0 or 400 Mbps FireWire port, and Buffalo provides cables for both interfaces. The DriveStation Duo has both six-pin and four-pin FireWire ports on the back of the unit, and since the included FireWire cable is a 4-pin to 6-pin cable, you can connect the DriveStation Duo to systems that use the more compact 4-pin port (such as notebooks or other low-profile systems). Doing so eliminates the need of a power adapter.

The DriveStation Duo’s black plastic chassis sports a built-in fan to help dissipate excess heat, and the unit runs very cool to the touch. In spite of that fan, it’s also extremely quiet— you certainly won’t hear it over the din of a nearby PC. There’s also a convenient power-down feature that you can activate by a switch on the back of the unit. When enabled, the DriveStation Duo automatically turns itself off when the PC it’s connected to is shut down, or when you disconnect the USB/FireWire cable.

You configure the DriveStation Duo in one of three storage modes. In the default mode, each disk is treated as an individual drive and receives it’s own drive letter. If you’d rather deal with just one drive letter you can switch to spanning mode, which combines the total capacity of both drives into a single large volume. If you prefer the data security redundant drives offer, configure the Duo as a RAID 1 mirror, which the cuts the unit’s overall capacity in half but ensures that data your survives even if one of the drives should fail.

Unlike similar products (most notably, the Maxtor One Touch III Turbo Edition) the DriveStation Duo doesn’t include a RAID 0 configuration option (which uses disk striping to increase performance). Although we’d prefer to see RAID 0 offered, we don’t necessarily consider it’s absence a deal-breaker since RAID 0’s performance benefit is limited on slow USB or FireWire interfaces, and using it increases your odds of data loss in the event of a hardware failure because even if only one disk dies, you lose the contents of both.

Extra Software
You can change the DriveStation Duo’s storage mode using an included utility — the process destroys any data on the disk, so be sure to do it before you put any information on the device. A separate utility partitions and formats the individual disks, but you can also do that job using Windows’ built-in Disk Management utility.

If you plan to use the DriveStation Duo to store very large files such as digital video, you might want to forgo Buffalo’s formatting utility, since it can format drives using only the FAT32 file system, which has a maximum file size of 4 GB. The DriveStation Duo comes formatted with FAT32 for compatibility reasons, since Windows, Mac and Linux systems can all read the file system. The drive also includes a copy of Memeo AutoBackup should you want to store system backups.

Double Up: Buffalo’s DriveStation Duo external storage device has two hard drives inside, not just one, for more room or extra data security.

Whatever you choose to store on it, the DriveStation Duo holds an awful lot of data, and if you want to protect all that information from prying eyes you can use Buffalo’s SecureLockWare encryption software — a nice addition you don’t get with many external drives.

SecureLockWare supports both 128-bit or 256-bit encryption, and it can be used to encrypt either individual files and folders or a whole disk. You encrypt data by specifying a password that must be subsequently entered in order to access the protected file, folder or disk.

As with changing the DriveStation Duo’s storage mode or partitioning/formatting a disk, encrypting an entire disk is a destructive process, so you can’t do it without erasing the data that’s already there. That said, when we moved an encrypted unit to another system, we weren’t able to see or access the drive in Windows (in Disk Manager it was displayed as an unknown partition).

Encrypting individual files or folders is more convenient; a right-click context menu lets you easily encrypt any file or folder, and you can use SecureLockWare to encrypt data located anywhere on your system, not just the data stored on the DriveStation Duo. However when encrypting files and folders, the resulting encrypted file only retains the first eight characters of the name, and the missing characters aren’t restored when you decrypt the file or folder.

The Bottom Line
If you need more capacity than a single external disk can provide, or if you require data redundancy in an external storage device, then the Buffalo DriveStation Duo will do the job handily. In fact, if your appetite for storage is so voracious that you need more than a terabyte, the Buffalo DriveStation Duo is one of only a handful of products available that can provide it.

Product: Buffalo DriveStation Duo (HD-W500IU2/R1)
Price: $249 (500 GB), $449 (800 GB), $499 (1 TB), $999 (1.5 TB)
Pros: available in up to 1.5 TB capacity; includes data encryption software
Cons: lacks RAID 0 support, drives are not easily upgradeable or replaceable

Joe Moran spent six years as an editor and analyst with Ziff-Davis Publishing and several more as a freelance product reviewer. He’s also worked in technology public relations and as a corporate IT manager, and he’s currently principal of Neighborhood Techs, a technology service firm in Naples, Fla. He holds several industry certifications, including Microsoft Certified Systems Engineer (MCSE) and Cisco Certified Network Associate (CCNA).