Guard picks scalable servers

The
National Guard recently chose servers to house the data for its nationwide
distance-learning network.


The Guard will install the 300-MHz Media Engine servers from Removable Media Solutions
Inc. of Rancho Cordova, Calif., in Distributed Training Technology Project classrooms, at
the network hub and at a hot site, said Lt. Col. Philip Vermeer, DTT product manager.


DTT is a nationwide distance-learning program aimed at fulfilling the National
Guard’s education requirements by training Guard members and giving communities tools
for economic development, Vermeer said.


The servers will run on an asynchronous transfer mode backbone linking 3,200 armories
and supporting multimedia computer training for 387,000 citizen soldiers and others [GCN, Jan. 26, Page 41].


The Guard will manage the network, and the states will manage local facilities. To
offset costs, Vermeer said, states can sell access to agencies and civilians 28 days a
month while the Guard isn’t using the network.


The classroom servers, which cost about $15,000 each, will first run 300-MHz Pentium II
processors. But RMSI expects to ship 333-MHz units this summer. Each classroom unit will
have 128M of EDO RAM, the hub servers 256M and the hot site server 384M of RAM, Vermeer
said.


RMSI developed the hardware to support Integrated Information Services, the
system’s network software from Booz, Allen & Hamilton Inc. of McLean, Va.


The project will link 162 classrooms by December; the Guard expects to add 600 more
connections by 2000.


The Media Engine will provide online and near-line storage of course material, as well
as backup, said Chuck Kucinski, director of information systems and information technology
at RMSI.


RMSI had many requirements to meet when it developed the server for the Guard project.


“I had never seen so many specifications in either government or the private
sector,” Kucinski said.


The primary requirements were for scalability, Kucinski said. First, he said, the
bureau wanted the system to have room to grow.


“When you have a nationwide network that spans 50 states and four territories, you
have to expect that the customer base for quality courseware will expand
exponentially,” Kucinski said.


Second, he said, the servers had to support three levels in the program hierarchy. End
users will be in classrooms of 25 to 30 users each. The classrooms then will link to four
regional hubs, each of which could eventually support 200 to 300 classrooms. The
classrooms in turn will link to a national hot site that will distribute tests and
courseware throughout the country.


Other requirements were compactness, easy transport, self-contained environmental
control, uninterruptible power, high availability and fast throughput, Kucinski said.


The heart of the Media Engine is a RAID storage subsystem that can support up to nine
hard drives, Kucinski said. Initially, each classroom will get three 9G disksof Level 5
RAID that will let the system run without interruption if a disk fails.


With RAID Level 5, the parity data, which is used to rebuild a bad disk, is striped
across all disks in the array, Kucinski said. Because one-third of each disk is reserved
for parity, the initial system in each classroom will have 18G of storage. But the Media
Engine can scale up to a terabyte of storage, Kucinski said.


The system includes a hot swap feature that lets technicians replace failed disks while
the server is running. The server can also rebuild the data onto the new disk without
interrupting service to users, Kucinski said.


The servers provide 100-Mbps throughput to the motherboard and network through
peripheral controllers and Ultra-Wide SCSI-3 channels, he said.


To meet the Guard’s specification for near-line storage, RMSI builders included a
digital linear tape drive.


When a user requests a program contained on tape, the courseware automatically loads to
the hard drive. Each tape, which also serves as backup, can hold up to 70G of compressed
data.


If any classroom needs more near-line storage, users can insert the tape drive into a
tape library that holds up to 15 cartridges.


The system includes a seven-drive CD-ROM array to support military training programs
stored on CD-ROM. In creating the front end to the program, Booz, Allen had to alter the
way Microsoft Windows 95 recognizes CD-ROM drives.


Normally, Win95 recognizes each drive as a lettered drive such as d: or e:. Because the
software would select courseware by drive letter, it would have no way of knowing if a
CD-ROM program had been moved to another drive or taken offline.


To solve that problem, Booz, Allen created a utility that lets users access CD-ROM
disks by volume name rather than drive designation. Because the volume name remains on the
CD-ROM, the program can find it regardless of drive, Kucinski said.


Despite the large number of components, the Media Engine cabinet, which weighs 700
pounds fully loaded, fits through standard classroom doorways. It is about 7 feet tall and
2 feet wide. It includes an uninterruptible power supply and environmental controls that
automatically switch fans on when the interior temperature becomes too hot.  

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