CCS: ORNL Mass Storage System Components

The Mass Storage Facility at ORNL currently consists of tape and disk storage components, IBM servers and High Performance Storage System (HPSS) software. As of mid-January 2004, the Mass Storage Facility contained 232 terabytes of data in over 4.8 million files.

Tape storage is provided by four StorageTek 9310 (Powderhorn) robotic tape libraries.

The StorageTek libraries can each hold up to 5000 cartridges. The libraries house a total of eighteen 9840 drives (20 GB cartridges, uncompressed), two 9940A drives (60 GB cartridges, uncompressed) and sixteen 9940B drives (200 GB cartridges, uncompressed). The 9840 and 9940A drives read and write uncompressed data at 10 megabytes/second; the 9940B reads and writes at 30 megabytes/second. The beneficial feature of the 9840 tape technology is its fast seek time for small file access; these are the performance drives. The 9940 tape technology provides the ability to store a larger amount of data on each tape cartridge for more voluminous data sets; these are the capacity drives.

The design of the CCS Facility has allowed for the ability to have data redundantly written on two separate floors of the facility. This provides for additional disaster protection as the two machine rooms are protected with different fire zones. User data is not only protected by writing twice, but we physically keep the media in separate robots, on separate floors.

Four types of RAID (Redundant Arrays of Independent Disks) are used in the Mass Storage Facility. There are Compaq StorageWorks disks, comprising about a half of a terabyte, (to be retired in 2004) IBM SSA (Serial Storage Architecture) drives comprising roughly a half a terabyte, IBM FastT-700 FibreChannel arrays comprising roughly one terabyte, and DataDirect Networks S2A8000 Fibrechannel disk array providing three terabytes of disk cache, with two more being added soon.

Robert Silvia -- email: silviarj@ornl. gov

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