John Merrill, head of SCD's Mass Storage System Group, and (L to R) computer operators Jirina Kokes, Julie Harris, and Melissa Breedlove mount the last IBM 3490 cartridge, transferring data to the MSS robotic library and completing a 15-month "data ooze."

Left, Melissa loads the last 3490 cartridge into the tape drive. Right, As the cartridge is read, its number shows up on the electronic display of the tape drive.

Photos: Lynda Lester, NCAR/SCD

Mass Storage System data migration complete

For the past 15 months, SCD's computer operators have been hand-mounting IBM 3490 cartridges onto tape drives in NCAR's Mass Storage System (MSS), transferring data from the old cartridges onto newer media in a process called "data ooze."

On 01 August 2003 at 14:30, SCD staff mounted the last 3490 cartridge, marking the end of a labor-intensive process that began on 02 May 2002

Over the course of the data migration, SCD staff mounted a total of 115,909 cartridges containing 4,189,431 user files—an average of one mount every 5.65 minutes, 255 times per day, 7 days a week. The total amount of data "oozed" was 58.9 terabytes.

The IBM 3490 cartridges were remnants from the mid-1980s, when the MSS consisted solely of library shelves of cartridges filled with research data. The 3490s were made read-only in early 1999, so none of them contained
any recently created files.

Storage technology has evolved since the 1980s, and new cartridges have higher capacities and data transfer rates. And whereas 3490 cartridges had to be hand-mounted, newer media are stored in StorageTek Automated Cartridge Systems ("silos"), and are mounted by high speed robots.

For more information on the MSS and its data holdings, see "Supersizing a community data trove."