Rutgers University Digital Repository
Operating Assumption #2 - Content and Use of the Mass Storage System
January 8, 2004
Definitions:
Online is storage on disk.
Near-line is readily-accessible storage on tape.
Offline is storage on tape for routine backup or disaster recovery. It is not accessible unless content from tape is restored.

The mass storage system, consisting of a high-capacity disk array and a tape library, will contain objects (metadata) and datastreams ingested into Fedora, in addition to temporary files and directories written by the Workflow Management System. Storage will be divided into three categories: online, near line, and off- line.

The mass storage system will contain objects and metadata ingested into Fedora and the storage will be divided between online, near-line, and offline. All content will be initially written to disk (online). From there, all content will be copied to tape for disaster recovery purposes (offline). If the content is archival, e.g. uncompressed TIFFs, uncompressed video, "master" -level material as opposed to derivatives in presentation formats, it will also be copied to tape storage in the library (near line) where it will live permanently, at which point it can be deleted from disk. If content is NOT archival, it will remain on disk permanently, i.e. datastreams in presentation formats will be stored on both online and offline storage while datastreams in preservation formats will be available only from near-line storage.

Reviewed by DAWG January 21, 2004
Revised January 23, 2004, January 27, 2004, February 4, 2004

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Posted April 23, 2004
URL: http://www.libraries.rutgers.edu/rul/staff/groups/dig_infrastructure/reports/assumption_02.shtml
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