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Migration of 3480s to Redwood: Progress Satisfactory

  Charles Curran IT/PDP


At the time that the introduction of the new STK automation equipment was announced, users were informed that IT intended to try to move user data off 3480 media onto the newer and fully automated Redwood media.

The 3480 cartridge was still in frequent use, but no longer supported by automation at CERN. The basic proposal was to copy all 3480 cartridges in the Tape Vault (some 200,000) onto 25 GBytes Redwood volumes, using VID-mapping features of the Tape Management System (TMS) to make this as transparent as possible to users. The new copies would be accessible for READ only, but this was not expected to be a great difficulty as this mode corresponded to the great majority of usage. The new media was to be provided by IT, as was the actual copying scheme and manpower.

I am pleased to say that this project, thanks to the goodwill and cooperation of all concerned, is now in its closing stages. It took a little longer than expected to start up, but from late July 1997 it has been possible to keep eight copy streams active for almost 168 hours/week, using the Tape Vault self-service copy stations and some 170 GBytes of dedicated stage disk. When no problems were met, over 5000 volumes could be handled in a week. You can find more details at URL:

http://wwwinfo.cern.ch/pdp/vm/migration.html

As the 3480 works finishes, work has started to migrate 3490s in the same way, starting with the busiest volumes and those that were previously in the SMCG robot. Although these volumes are not so numerous (some 20,000) they take longer to copy: they contain more data, and we can expect to use only 6 streams at best. Nevertheless, it is still expected that all tape handling apart from preparation and import/export support activities will be automated by the end of 1998.


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