Digital Preservation Panel

Medusa at the University of Illinois at Urbana-Champaign: A Digital Preservation Service Based on

PREMIS

Kyle Rimkus, Preservation LibrarianTom Habing, Head of Software Development

University of Illinois Urbana-Champaign Library

Short Paper Presentation

July 23, 20132013 Joint Conference on Digital Libraries

Indianapolis, Indiana

OAIS Management

SIP: Submission Information PackageAIP: Archival Information PackageDIP: Dissemination Information Package

Access Systems• ContentDM: digitized unique and rare materials from locally held

collections• DSpace: IDEALS institutional repository and electronic theses and

dissertations• ARTStor: image collections used for teaching and learning• Internet Archive: books digitized through participation in the Open

Content Alliance• HathiTrust: digitized books• Voyager catalog and locally-developed web pages: digitized books and

book-like content • Archon: digitized manuscripts and archival content • Olive ActivePaper: digitized newspapers• Ensemble Video: streaming video content, primarily digitized from the

University Archives• DLXS: XML-driven text-analysis research projects

Medusa Digital Preservation Service

• https://medusa.library.illinois.edu/• Documentation:

https://wiki.cites.illinois.edu/wiki/display/LibraryDigitalPreservation/Home

• enduring storage and management environment for digital content at the University of Illinois at Urbana-Champaign Library

• Infrastructure based on the Open Archival Information System reference model (OAIS)

• policies and underlying technological architecture designed in keeping with the model of a Trustworthy Digital Repository (TDR)

National Digital Infrastructure and Information Preservation(NDIIPP) Program grants•Phase I : 2004-2007•Phase II: 2007-2010

“Hub and Spoke” (HandS tool suite): http://dli.grainger.uiuc.edu/echodep/hands/index.html

Metadata for Digital Preservation

Intellectual entities

Intellectual entities RightsRights

ObjectsObjects AgentsAgents

EventsEvents Metadata standards in Medusa:•PREMIS (digital preservation metadata)•MODS (descriptive metadata)

• Quick Overview of Architecture

• Modeling Complex/Compound Objects in PREMIS

• Fedora Content Models for PREMIS

Part 2

Medusa Technical Architecture

Disaster RecoveryPrimary

Bit-level Preservation Object-level Preservation

Collections Registry

Fedora

Blacklight

SOLR

Content Storage Content Storage

Hydra

DX6000 Storage Cluster

Storage Node

Storage Node

...

DX6000 Storage Cluster

Storage Node

Storage Node

...

Replication

Content File Server

SOLRizer

SQL

Dat

abas

e

File SpoolAkubra

Modeling Complex/Compound Objects with PREMIS

Intellectual entities

Intellectual entities RightsRights

ObjectsObjects AgentsAgents

EventsEvents

PREMIS Relationship Type & Subtype• Collection

• Is Member Of• Metadata

• MODS• MARC• …• Parent

• Basic Image Asset• Production Master• Archival Master• Screen Size• …• Parent

• Paged Text Asset• Pages• LoRes PDF• HiRes PDF• …• Parent

• Basic Compound Asset• First Child• Child• Parent• Next Sibling• Previous Sibling

• Derivation• Has Source• Is Source Of

• …

Example

<relationship> <relationshipType>Paged_Text_Asset</relationshipType> <relationshipSubType>Pages</relationshipSubType> <relatedObjectIdentification> <relatedObjectIdentifierType>LOCAL</relatedObjectIdentifierType> <relatedObjectIdentifierValue>MEDUSA:xxx.2</relatedObjectId </relatedObjectIdentification> </relationship>

Page Images

RepresentationMEDUSA:xxx

CollectionIs Member Of

Filexxx_1.jpg

Paged Text AssetPages

RepresentationMEDUSA:xxx.2

Basic Compound AssetFirst Child / Parent

RepresentationMEDUSA:xxx.1

Filexxx_1.jp2

Basic Image AssetProduction Master

RepresentationMEDUSA:xxx.2

Basic Compound AssetNext Sibling / Previous Sibling

Filexxx_2.jpg

Basic Image AssetScreen Size

Filexxx_2.jp2

Basic Image AssetProduction Master

Basic Compound AssetNext Sibling / Previous Sibling

...

Basic Compound AssetParent

Basic Image AssetScreen Size

• Separate Fedora Object and Content Model for Each PREMIS Entity

• All PREMIS relationships are converted to Fedora RELS_EXT

PREMIS to Fedora Content Model

-PREMIS_EVENT()

-DC-RELS_EXT

PID: EVENT_1234

-PREMIS_AGENT()

-DC-RELS_EXT

PID: AGENT_1235hasAgent

-PREMIS_REPRESENTATION_OBJECT()

-DC-RELS_EXT

PID: REPRESENTATION_OBJECT_1236

-PREMIS_FILE_OBJECT()-CONTENT()

-DC-RELS_EXT

PID: FILE_OBJECT_1237relationshipType.Subtype

hasObject

• info:fedora/afmodel:MedusaPremis_FileObject

– DC– RELS-EXT • http://medusa.library.illinois.edu/ns#relationshipTypeRelationshipSubtype• http://medusa.library.illinois.edu/ns#relationshipTypeRelationshipSubtypeLinkingEvent• http://www.loc.gov/premis/rdf/v1#hasEvent• http://www.loc.gov/premis/rdf/v1#hasRightsStatement• http://www.loc.gov/premis/rdf/v1#hasIntellectualEntity

– PREMIS-FILE-OBJECT (inline PREMIS XML)– CONTENT (managed content)

Fedora CModel for PREMIS File Object

Questions?

• Medusa documentation (more coming soon) :• https://medusa.library.illinois.edu • https://wiki.cites.uiuc.edu/wiki/display/

LibraryDigitalPreservation/HomeMore on digital preservation at UIUC:• http://www.library.illinois.edu/prescons/

services/digital_preservation/digital_preservation.html

• Contact: rimkus@illinois.edu