BIOS: Technology Means Business

Plextor has overcome the problem of small business networks requiring extra storage with a convenient 250GB Network Attached Storage (NAS) device. As well as providing shared storage across the network, the PX-EH25L integrates a print server that allows you to share a printer over the network when connected to the NAS via USB, as well as an automated backup scheduler that lets you backup the device's data onto a USB-connected hard disk drive. Additionally, the PX-EH25L includes a security feature that allows administrator to limit access to certain folders, and it can be configured as a dedicated FTP server. What more do you need, except perhaps a more accommodating capacity?

Pros: Compact size; built-in NIC and print server; security controls
Cons: Only 250GB; no built-in DHCP server or FireWire port

This new disk drive is designed to broaden Plextor's product portfolio to provide solutions for home enthusiasts and businesses to convert and manage data content. In addition to optical storage, flash memory and, more recently, digital video converters, Plextor has also started to offer portable hard disk drives (£69.99 ex. VAT) for those requiring extra mobile storage.

The PX-EH25L is a compact (420x265x131, 1.2kg) NAS device encased in a relatively robust metal-and-plastic housing. Its form factor is slim and attractive but it can only be used in a vertical position. The device supports Windows (98SE and later) and Mac OS platforms (Mac OS 8.1 or later), so you can forget about connecting it to a Mac or Linux system.

Connectivity options are all located at the rear of the device, comprising a single 10/100Base-TX NIC and two USB 2.0 ports (used for connecting another hard disk drive for backup or a printer). There's also a power switch, allowing you to turn the device on and off at the beginning and end of each working day as well as Power and Activity LEDs at the front of the drive. However, there's no write protection switch to prevent accidental deletion of data and no FireWire port.

The drive itself is based on a 7200rpm unit with an 8MB buffer and average seek time of 8.2ms. While these specifications can be bettered by dedicated internal hard disk drives, they're actually very good for an external USB/LAN drive. The only real bottleneck you may encounter will be when dealing with large files, such as videos. If speed is mission critical, you should go for an internal 15,000rpm SATA drive with a 16MB buffer.

Setting up and configuring the PX-EH25L requires a little networking know-how, unlike installing a typical USB hard disk drive. For instance, there's a MDI/MDI-X selector switch at the rear of the drive that has to be configured in accordance with the network equipment to which the PX-EH25L is connected - the MDI-X setting is used when connected to the MID-X port of a computer or hub, and the MDI switch is used when connected straight to a hub.

You then have to find the drive using 'My Network Places', just as you would when finding any other network-attached device. This, of course, is a little more involved than simply plugging in a USB hard disk drive and having it recognised instantly by Windows.

The process is also made a little more complicated due to the lack of a built-in DHCP server. Short for Dynamic Host Configuration Protocol, DHCP is a protocol for assigning dynamic IP addresses (an identifier for a computer or device) to devices on a TCP/IP network.

With dynamic addressing, a device can have a different IP address every time it connects to the network. In some systems, the device's IP address can even change while it is still connected. DHCP also supports a mix of static and dynamic IP addresses.

Dynamic addressing simplifies network administration because the software keeps track of IP addresses rather than requiring an administrator to manage the task. This means that a new computer can be added to a network without the hassle of manually assigning it a unique IP address. Many ISPs, for instance, use dynamic IP addressing for dial-up users.

Because the PX-EH25L doesn't have a built-in DHCP server, you'll have to connect it to a network that does in order to assign it an IP address. Thankfully, the default setting of the PX-EH25L allows it to automatically obtain an IP from a DHCP server. [7.5]