Storage

Institutions and scientists worldwide rely on the facility’s resources to conduct research. LONI is architected to achieve a fault-tolerant, high-availability systems design to ensure 24/7 functionality. Concurrent with its graphics and computation systems, the laboratory uses a fault-tolerant storage area network (SAN) to accommodate current and projected storage requirements. The SAN hardware infrastructure is composed of the cluster and SMP supercomputers previously mentioned, RAID storage, dual robotic tape silos and a full complement of Brocade fibrechannel switches, delivering up to 800 megabytes per second data throughput. Alternate paths exist throughout the fabric so that no single point of failure exists, guaranteeing access to critical data and processing power. Two quad-processor 500MHz MIPS-R14000 processor SGI Origin300 servers mediate all data transactions and provide networking services. These two machines act as primary and backup metadata servers for the software component of the SAN—CXFS, a shared, high performance cluster filesystem and DMF, an automated hierarchical storage management subsystem that transparently moves data online to disk and offline to tape. A high availability application ties both servers together and ensures failover in the case of hardware failure. LONI relies on two silos, a Storagetek SL8500 and a Powderhorn 9310, to store mirrored copies of the facility's nearline tape data with a combined capacity of nearly 4 petabytes. Both serve alongside DMF as the back end of the SAN. Furthermore, these tape robots are housed in two different buildings, ensuring that catastrophic events in any one data center will leave a copy of all tape data intact in another data center. Seven high-speed 40-gigabyte and two high-capacity 400-gigabyte tape drives provide LONI's tape services. To leverage the available SAN throughput, an SGI TP9500, TP9400 and a TP9100 RAID5 arrays as well as SUN 3510s provide nearly 60 terabytes of fault-tolerant disk storage.