Keeping Data Within Reach

Storage options include online, offline and near-line solutions on media such as tape, hard disks and CD-ROMs. In many cases, the best storage solution is a combination of these options.

In the Information Age, government agencies must find ways to handle data generated, shared and demanded at ever-increasing rates.

And it's not just handling the volume of data that poses a problem. Today's information technology managers need to store all that data securely and determine how often and how quickly users need to access it.

Storage options include online, offline and near-line solutions on media such as tape, hard disks and CD-ROMs. In many cases, the best storage solution is a combination of these options. To pick the solution best for your agency's needs, consider the following questions:

Do users need instant access to data on a network? If so, an online storage solution is necessary.

The most powerful online solution is a Redundant Array of Independent Disks device attached directly to the servers or as an additional storage device connected to the network. RAID solutions offer immediate access across the network to stored data, but this type of architecture likely will cost you more money per megabyte. Another downside: Once a RAID device is full, you need to add disks to the system or put an additional device on the network. That's decidedly more expensive than simply inserting a new data cartridge or storing the old data offline.

What if users don't need instant access to data? Tape libraries are a good option, especially if cost is a factor in your decision.

Network tape libraries often are referred to as near-line storage. Data is accessible, but not as quickly as with RAID units. When a user requests stored data, a robotic arm locates and retrieves the appropriate tape from the library and inserts it into the drive. The drive works its way through the tape until it finds the requested data and sends it to the server. The process can take 30 seconds to five minutes, depending on where the data is located on the tape.

Such delays can be inconvenient for some users, but a trade-off lies in the ease of adding more storage space. Once a library is full, tapes can be taken offline, archived and replaced with blank tapes. This is a faster and less expensive way to increase data storage than adding RAID devices to the network. Tapes also can be easily moved to other storage locations for safety.

In this look at storage, the Test Center tried several tape storage devices ranging from single-server to departmental solutions. Our purpose is not to provide a complete survey of available products. Rather, we intend to delineate the range of options available to users. In selecting products to review or test, we chose three vendors who are well known in government markets and who are representative of the industry.

— Andreas Uiterwijk