At lab, speed causes storage shortfall

The lab used its prediction models to simulate wind speed, above, and atmospheric pressure and temperature, below, for Tropical Storm Gustav.

When the Naval Research Laboratory acquired a fast computer for testing weather prediction codes, it became clear that a lot more storage capacity was necessary.

The code developers at the Monterey, Calif., lab were more concerned about redundancy than long-term archiving. They installed a storage area network from Zzyzx Peripherals Inc. of San Diego.

The Meteorological Applications Development Branch, part of the lab's Marine Meteorology Division, writes weather prediction systems for operational applications, said Patricia Phoebus, acting division superintendent. The researchers develop and validate computer simulations with global weather data collected daily from satellites and ground sensors.

The Fleet Numerical Meteorology and Oceanography Center, located on the Monterey campus, uses the finished codes to make operational weather and sea surface forecasts for the Defense Department.

'We're just on the R&D side,' Phoebus said.

Each simulation processes tremendous amounts of data, representing 3-D fields of meteorological parameters, such as wind speed and air temperature. The test runs of new and revised codes average two to four hours of computer time each.

Typical output for a five-day global forecast is 1G to 5G of data, said Rich Hodur, head of the lab's Atmospheric Dynamics and Prediction Branch. A three-day regional mesoscale forecast generates up to 3G.

Ted Tsui, head of the development branch, said he and his colleagues study ways to translate the weather models' output into information relevant to naval operations. For example, Navy surface ships need advance notice of storms to seek safe harbor.

The Navy also needs detailed predictions of wave height and of dust in the upper atmosphere, Phoebus said.

First SAN

The Zzyzx system is the lab's first SAN, said Allan Caughey, a Unix systems administrator at the lab. The SAN currently connects to just one machine, a 128-processor SGI Origin 2000. Fleet Numerical passed it along after acquiring a 512-processor SGI Origin 3000 supercomputer as its primary platform.

The division started using the SAN in March for storage for the SGI Origin 2000, which had only about 60G of internal storage.

The storage network includes four Zzyzx RocketStor 2000-F RAID arrays, each with more than a dozen 181G Seagate disks totaling about 2.5T.

The Zzyzx SAN has enough rack space for 30T worth of disks, but division officials invested in 10T of raw capacity initially, Caughey said.

Configured at RAID Level 5 for redundancy, the SAN provides 8T of usable storage. The branch uses about half that so far, Caughey said.

The storage network also has two 16-port SANbox2 Fibre Channel switches from QLogic Corp. of Aliso Viejo, Calif. Each port has 2-Gbps bandwidth, and each RAID array is connected to both SAN switches for redundancy.

The RAID management server, a generic rackmount unit, runs RAID management software from Zzyzx and a SAN management application from QLogic, under Microsoft Windows 2000.

The SAN 'takes up very little floor space,' Caughey said. All the components'disks, RAID controllers and SAN switches'fit into two standard racks at the Fleet Numerical data center.

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