National Digital Stewardship Alliance is a consortium of organizations (212, including, Digital Public Library of America, Yale University Library, and New York Public Library (NYPL)) committed to the long-term preservation of digital information.
Levels of Preservation
NDSA Levels of Preservation (LOP), a rubric that can provide guidance for institutions that want to do digital preservation, or are doing digital preservation. The rubric sets out a minimal set of standards an insitution can aim for and progressions that they can then seek to achieve. Levels of Preservaiton is an understandable and pragmatic guide for folks in the industry.
Levels of Preservation, Level 1
Protect your data
Levels of Preservation, Level 2
Know your data
Levels of Preservation, Level 3
Monitor your data
Levels of Preservation, Level 4
Repair your data
Level 1: Storage and Geographic Location
- Two complete copies that are not collocated.
- For data on heterogeneous media (optical disks, hard drives, etc.) get the content off the medium and into your storage system.
Level 2: Storage and Geographic Location
- At least three complete copies.
- At least one copy in a different geographic location
- Document your storage system(s) and storage media and what you need to use them.
Level 3: Storage and Geographic Location
- A least one copy in a geographic location with a different disaster threat.
- Obsolescence monitoring process for your storage system(s) and media.
Level 4: Storage and Geographic Location
- At least three copies in geographic locations with different disaster threats.
- Have a comprehensive plan in place that will keep files and metadata on currently accessible media or systems.
Level 1: File Fixity and Data Integrity
- Check file fixity on ingest if it has been provided with the content.
- Create fixity info if it wasn't provided with the content.
Level 2: File Fixity and Data Integrity
- Check fixity on all ingests.
- Use write blockers when working with original media.
- Virus-check high risk content.
Level 3: File Fixity and Data Integrity
- Check fixity of content at fixed intervals.
- Maintain logs of fixity info; supply audit on demand.
- Ability to detect corrupt data.
- Virus-check all content.
Level 4: File Fixity and Data Integrity
- Check fixity of all content in response to specific events or activities.
- Ability to replace/repair corrupted data.
- Ensure no one person has write access to all copies.
Level 1: Information Security
- Identify who has read, write, move, and delete authorization to individual files.
- Restrict who has those authorizations to individual files.
Level 2: Information Security
Document access restrictions for content.
Level 3: Information Security
Maintain logs of who performed what actions on files, including deletions and preservation actions.
Level 4: Information Security
Perform audit logs.
Level 1: Metadata
- Inventory of content and its storage locations.
- Ensure backup and non-collocation of inventory.
Level 2: Metadata
- Store administrative metadata.
- Store transformative metadata and log events.
Level 3: Metadata
Store standard technical and descriptive metadata.
Level 4: Metadata
Store standard preservation metadata.
Level 1: File Formats
When you can give input into the creation of digital files encourage use of a limited set of known open formats and codecs.
Level 2: File Formats
Inventory of file formats in use.
Level 3: File Formats
Monitor file format obsolescence issues.
Level 4: File Formats
Perform format migrations, emulation and similar activities as needed.