When K-mart launched its e-commerce site, called BlueLight.com, a few
months ago, this nationwide retailer turned to solid-state disk technology,
not mechanical disk drives, to provide lightening fast delivery of e-mail
message to customers. In fact, David Hill, the Aberdeen Group’s
research director for storage, says that solid-state disk technology has
become useful for Web-based applications where mechanical disks can’t read
and write fast enough to keep up with the fast processors and database
systems. For example, both Yahoo and EBay use solid-state disks to store
frequently used files, such as database logs of transactions, which are too
large and too slow for mechanical disks to handle.
At K-mart’s BlueLight.com, solid-state disks help to accelerate the
SendMail application by blasting out 250,000 mail messages an hours. This
speed is about 100 times faster than what the company could get from server
hard disks, according to a source at Imperial Technology, the provider of
K-mart’s solid-state disks.
Solid-solid disks, which have their roots in the mainframe-era, earn
their keep by storing the handful of frequently used files that ate at the
largest causes on input/output, or I/O bottlenecks. These common traffic
jams occur when a server’s central processor has to wait for disks to
complete a read or write before it can move to the next transaction.
By relocating these few key files from mechanical disk drives to a speed
demon of a solid-state disk drive, you can increase an application’s
performance by up to 50 percent. This increase in speed enables you to put
off purchasing an expensive, new high-performance server, as well not having
to deal with the cost of managing this server.
Ironically, solid-state disks aren’t disks at all. They consist banks of
dynamic RAM chips packed into a cabinet and configured to appear to a server
as just another storage device containing disk drives. Solid-state disks
usually contain one mechanical disk drive. It acts as a battery-powered
safety net where data can be stored temporarily in case an electrical failure
shuts down the memory chips.
Undoubtedly, solid-state disks can make life happier for database
administrators and systems administrators. But there’s a catch – the price.
Storing data on a solid-state disk can range from $10 per megabyte to $15 per
megabyte as opposed to 5 cents per megabyte with a mechanical disk drive. To
this end, organizations, such as Kmart, Ebay, and Yahoo, can easily cost
justify putting their most used files on solid-state disks.
Server consolidation may be another area where you can perhaps cost justify
using solid-state disks and eliminating I/O bottlenecks. Centralizing IT
operations can mean fewer, more manageable servers. But server consolidation
often results in concentrating data traffic. The government has stepped up
its efforts to use solid-state disks to support server consolidation.
Rather than use solid-state disks to eliminate I/O bottleneck, you can
try to boost server performance by increasing the amount of server’s internal
main memory. The drawback here is that if the server crashes of locks up,
the data in memory gets lost. On the other hand, solid-state disks don’t
have this problem. As standalone devices, solid-state disks come with their
own backup capabilities.
Today solid-state disks appear a bargain compared to their $10,000 per
megabyte price tag in the mid 1980s. They also have shrunk from the size of
a refrigerator to a rackmounted pizza box.
Elizabeth M. Ferrarini is a free-lance writer from Boston,