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OCFL v1.0
OCFL is an open standard for storing digital objects in a repository-independent and preservation-friendly format. It aims to ensure completeness, parsability, robustness, versioning, and storage diversity. The standard was developed through an open community process and draws on existing digital preservation best practices. An OCFL storage root contains digital objects and their metadata and versions arranged in a filesystem structure. The standard is now in version 1.0 along with implementation notes and validation tools.
OCFL v1.0
- 1. OCFL v1.0 –The Oxford Common File Layout Andrew Hankinson (University of Oxford) Neil Jefferies (University of Oxford) Rosalyn Metz (Emory University) Julian Morley (Stanford University) Simeon Warner (Cornell University) – presenter Andrew Woods (LYRASIS) #WeMissiPRES, online, 2020-09-22/23/24
- 2. OCFL is … anopen community effort to define an application-independent way of storing versioned digital objects for long-term digital preservation
- 3. Origins and Process •2017 discussion among digital repository architects about the ideal layout and characteristics for repository storage (in Oxford) • Initial community meeting (47 attendees from 32 institutions) • Collected use cases, best practices, recommendations • Editorial group, regular community meetings and open process on github • Significant design influences from Library of Congress Bagit format and Stanford University Moab experience (see https://doi.org/10.3390/publications7020039)
- 4. 1. Completeness – sothat a repository can be rebuilt from the files it stores • The complete intellectual object is stored together with its metadata • Falls in line with standards such as Trusted Digital Repositories (TDR, ISO 16363), NDSA Levels of Preservation, and Open Archival Information Systems (OAIS) • Allows ease of mapping from one system to another These standards typically talk about what you should do, but not how OCFL provides the how
- 5. 2. Parsability –both by humans and machines, to ensure content can be understood in the absence of original software • In disaster recovery situations, humans should be able to understand the content • Machine readability allows for simple applications to be placed on top of an existing OCFL storage root
- 6. 3. Robustness – againsterrors, corruption, and migration between storage technologies • Strong fixity is baked into OCFL • Objects can easily be validated using the inventory.json file • Objects can be completely self- contained
- 7. 4. Versioning –so so that a repository can make changes objects while persisting their history • Changes to objects are tracked over time, entire history can be reconstructed using the inventory.json file • Content for a version is immutable once written • Forward delta versioning reduces the amount of content stored (supports delayed description workflows)
- 8. 5. Storage diversity –to ensure content can be stored on diverse storage infrastructures including cloud object stores • Supports conventional filesystem metaphor • Designed to work with various storage infrastructures including object stores prevalent in cloud offerings (e.g. Amazon S3 API). • Allows deduplication of content, lowering overall storage costs
- 9. OCFL v1.0 First alphaOctober 2018 Beta draft June 2019 Version 1.0 July 2020 – specification and implementation notes Validation and manipulation tools implemented in multiple programming languages • Stand alone tools through • Fedora 6 using OCFL for persistence (in development)
- 10. Specification Describes: • OCFL Objects– including the object structure, versioning, and the inventory.json which provides a comprehensive registry of the object • OCFL Storage Root – how objects are arranged with examples to illustrate use Implementation Notes Recommendations and practices for implementing the specification, including: • Digital preservation issues – including rebuildability and fixity • Storage choices – including different content cases and infrastructures • Client behaviors – to support common operations and objects in motion
- 11. Thank you! Details andlinks to get involved: https://ocfl.io/
Editor's Notes
- #2 I'd like to thank the We Miss iPres festival and the Digital Preservation Coalition Awards for the opportunity to speak today I'm going to briefly present about OCFL - the Oxford Common File Layout I’m speaking on behalf of the OCFL Editorial Group which comprises
- #5 I’d like to focus on five key requirements that OCFL meets