The Migration Saga�Fedora 3.8 to 5/6/7? at The National Library of Wales�Siân Thomas – Head of Systems, NLW

Background – National Library of Wales

• Founded by Royal Charter in 1907
• Legal Deposit Library
• Focused on the culture and history of Wales and the Celtic nations
• Home to a broad range of collections, including rare books and manuscripts, archives, maps, art works, photographs, film and video, sound material – and much more
• Actively digitising collections for broader access since late '90s. 

www.library.wales

Background – Fedora at NLW

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• Procured packaged DAMS (VITAL) in 2005 – built on Fedora 2
• Last migration to 3.8.1 done in 2017. 
• Many large and disparate digital collections, photographs, prints, manuscripts, wills, journals, newspapers maps. 
• c. 6 million objects on Fedora 3 currently, ingest is still ongoing. 
• Access via IIIF integrated into websites and catalogues

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www.library.wales

www.library.wales

www.library.wales

Outline of DAMS environment

Digitisation outputs

Camel workflows

Digital Archive

Access stack (IIIF)

Fedora

Ingest workflows

METS

www.library.wales

Drivers for change

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• Cyber security compliance
• Reduced resources and loss of expertise
• Broken workflows / project hangovers
• Need to implement new workflows
• Complexity developed over time

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www.library.wales

The journey begins...

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• Had looked at Fedora 4 back in 2014
• Started looking at Fedora 5 in 2019
• 2020...
• Started again in earnest in 2022
• Prioritisation issues
• Staffing changes and resource challenges

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www.library.wales

The approach

• Analysis of what we have – 53 different models

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www.library.wales

www.library.wales

The approach

• Analysis of what we have – 53 different models
• Identify key similarities and differences
• Keep it simple!
• Remember core principles: 
• Preservation
• Sustainability
• Stick to strengths
• Migration, update, ingest and access

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www.library.wales

New models

• One, Two and Three-levels: 
• Image binaries attached to lowest level
• Descriptive record binary attached to highest level. 

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• One-level – photographs, wills
• Two-level – digitised books, manuscripts, photograph collections
• Three-level – newspapers, journals

www.library.wales

To PCDM or not to PCDM?

• Had identified standard early on
• Good adoption by community
• IRIIIF Tool for IIIF manifest generation
• Death by proxy!

www.library.wales

www.library.wales

To PCDM or not to PCDM?

• Had identified standard early on
• Good adoption by community
• IRIIIF Tool for IIIF manifest generation
• Death by proxy!
• METS to the rescue
• Have adopted some elements, but expanded NLW namespace for others

www.library.wales

Migration itself

• Take copy of live data
• Pre-migration tasks: 
• Update archival datastreams
• Remove unwanted datastreams
• Size=0 error
• Run migration
• Indexing....
• Testing - great results!

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www.library.wales

Endless indexing!

• First production migration (Sept 24), initial reindex ran for a month!
• c. 6m Fedora 3 objects > c. 53m OCFL objects
• Started again with a smaller sample, lots of iterations and testing
• Most recent full migration indexed in around 3 days
• Triplestore indexing
• Multiple failures
• Optimisation and throttling
• Possible memory leak issue
• Managed to complete in two weeks. 

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www.library.wales

Where are we now?

• Setting up eventual production server
• Working on migration phase 2 – modifying migrated output to fit new models
• Re-developing ingest workflows
• New access stack 
• Switch to Fedora 6 for ingest Jan 2026

www.library.wales

What’s next?

• Lots of post-migration tasks: 
• Long tail clean-up tasks
• New IIIF manifest generation processes
• Re-establish ingest for newspapers and journals
• Develop new workflows: 
• AV material
• Archival material
• Born-digital material
• Fedora 7

www.library.wales

Diolch yn fawr - Thankyou

sian.thomas@library.wales

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www.library.wales