Trying to sort through network-attached storage options? The nice thing about NAS is that you have lots of choices - but it can get confusing as you examine the different products. This overview will discuss the differences between NAS types and products and point you to some good options for the small to midsized business.

Besides being a replacement for a standard PC-based Windows or NetWare server, NAS devices are great for small businesses or remote offices where support staff is thin to nonexistent. They also fit the bill if you need to place a server in a public area and want the added security of not having a keyboard and monitor to tempt prying eyes and fingers. And some offer easy methods of adding extra storage when the original drives inevitably fill up with files.

The table below shows a range of NAS devices, from the midrange to the low end. Linked product names point to the 8wire review for that device.

Value

When you first look at the price tags for these devices, they can come as a bit of a shock, especially since you can buy 80-GB disks these days for about $300. However, when you consider everything else you need to do to assemble a network server, the NAS servers can be a very cost-effective alternative to installing a new PC-based server on your network. Adding additional storage to your network with a NAS device is very simple, fast, and doesn't disrupt your existing network configuration. You just connect the box to power and network, configure a few parameters, and within minutes you have gigabytes of disk space available.

Contrast that with setting up a PC, installing an operating system or upgrading an existing server by taking it offline to add a bigger disk. The second factor is the extra components that come with several of the units, such as RAID drives and disk mirroring software, extra power supplies and other gear normally found only on high-end servers. Some also permit clustering both to add capacity and to improve availability. Finally, if you are connected to the Internet and worried about server security, the NAS devices are hardened and don't offer any open ports or other loopholes for hackers to take advantage of.

Usability

Each device can be used as a primary domain controller and a Dynamic Host Configuration Protocol (DHCP) server to dole out IP addresses across your network, should you need something to do this. You can turn these options off if you already have these services taken care of with a regular PC server. We found all the devices easier to set up than a standard Windows file server. The downside with these units is that most don't include connectors for keyboards or screens, so sometimes debugging problems and troubleshooting can be difficult using the configuration software that comes with each unit.

All the devices can fit with 10-Mbps or 100-Mbps Ethernet networks, and can automatically sense the appropriate speed without user intervention. Some units come with Gigabit Ethernet or multiple Ethernet ports as well. This can be handy if you have large networks or multiple network segments that you want to connect your NAS device to, or need a redundant network connection.

Capacity

The first decision you will have to make is how much disk space will you need, and how you want it configured. While you can never have enough disk storage for your network users, it makes sense to try to find the appropriate target. In the table shown below, the NAS units range from 8 GB to several terabytes of disk space. A good rule of thumb is to have 1 GB for every network user if they aren't producing graphic images and presentations, and 10 GB for every user who is.

The lower-end models lack support for RAID drives and the added data protection and redundancy of this specification. The more expensive models offer RAID along with upgrade options which allow you to add additional disk storage when you run out of room. Of course, if you do configure these NAS units for RAID or disk mirroring, that might halve your quoted disk capacity. The good news is that you will increase the potential reliability of the unit by having a second copy of your files in case the primary copy gets damaged. The higher-end models also come in 1U or 2U sizes that are perfect for 19-inch rack mounting, but this can be a pain if you don't have a rack and just want to place them in your office out of harm's way.

Network Integration

Next, you'll want to take stock of your network and ensure your new storage server will support all of your client operating systems and protocols. All units shown in the table above support Windows networks, and some also offer support for Unix and NetWare clients, as well as being able to share files among Macintoshes and offering access to their files from any Web browser. Speaking of Web browsers, most of these units offer some kind of browser-based software utility to manage their storage configuration and setup access controls and such.

Also investigate other options that come with the units. The SMC Barricade unit offers an 8-port hub and router as part of the package. The Linksys Gigadrive comes with a print server port. HP's SureStore comes with its own CD burner and backup software routines. Some of the units come with external SCSI connectors that can be used to connect a tape drive for backups or additional hard disks if you run out of room on the internal disks.

Finally, you'll want to investigate how these units integrate with your existing Windows and other directory services on your network. If your network only has a dozen or so users, it isn't a big deal to set up user accounts on the NAS device for everyone. But if you have several dozen users, you'll want a unit from Quantum, Maxtor, or Intel, among others; these units will import users from your Windows Active Directory or domain list automatically.

Once you take these factors into account, buying a NAS device isn't difficult. The biggest challenge is that this remains a very active market, with products coming and going as vendors upgrade their features or add additional storage capacity to their units. As 8wire continues to review these devices, check this page to see how they compare in terms of usability, performance, and price.

David Strom has written over a thousand articles for various computer trade publications and Web sites, and publishes his own essay series called Web Informant that can be found at http://strom.com. His latest book, Home Networking Survival Guide, was published in Sept. 2001 by McGraw-Hill/Osborne and can be found at Amazon.com and other major book retailers.