Associated with the Digital Preservation Framework’s Technological Support Levels
The University of Minnesota Libraries uses a variety of preservation actions based on general preservation strategies to be able to preserve digital materials for the long-term. The Libraries’ Digital Preservation Framework document describes two technological support levels. These levels assume a continuum of actions from less to more as the support level increases. This document discusses the continuum of those preservation actions performed by the Libraries.
Fundamental Preservation Actions
All materials receive the following:
- One local copy (secondary copy) of the data is stored separately from the Libraries primary copy
- One remote copy stored at a separate geographical location, preferably on a different system (such as tape)
Risk Mitigated: Loss of data, including loss of use across all local systems.
- Fixity checks created at time of receipt (if not received with objects)
- Fixity checked when content is moved from one location to another
- Fixity is periodically checked on at rest items [set periodically]
- Corrupted items will be corrected from non-corrupt copies.
- Provenance of objects will be documented and traced as appropriate.
Risks mitigated: Objects protected against bit-rot (media corruption). Objects protected against accidental changes. Objects will be traceable back to their source, to verify authenticity.
- Virus checking on all received materials
- Limited access to main preservation storage area
- Monitor and audit and document who has read and read/write access to the primary and secondary storage locations.
- Workflows will use authorizations and document the chain-of-custody of people/roles allowed to perform tasks such as ingest, storage, and edits.
Risks mitigated: Prevent corruption of data via viruses. Prevent unauthorized changes or unauthorized access to the data. Provide a chain-of-custody and a history of actions as proof of due diligence.
Interpretability over time
- At minimum guarantee that the bits deposited will be the bits that are returned upon request. In addition, file formats will be identified, recorded and tracked where possible.
- Identification: format(s) of items will be identified if possible
- Validation: the conformance of the identifiable item to the format specification will be validated and recorded, if possible
- Metadata: technical metadata about the items will be generated and preserved alongside the items
- Formats at risk: the data owners will be warned when their data is preserved in an at-risk format, if possible
Risk mitigated: Attempt to maintain the ability to recover and understand the preserved items at a later date. Prevent loss of comprehensibility caused by changing standards and technologies over time.
- Materials transferred to the University Libraries for preservation must either come from within the Libraries or have a written agreement stating or allowing for:
- Owners have the right to grant the Libraries permission to preserve and/or provide access to the materials.
- Libraries has the permission to preserve the materials over time including using file format migration
Risks mitigated: Ensure chain-of-custody and management of preserved assets over long periods of time.
Advanced Preservation Actions
- A third copy stored offsite (most likely on tape)
- Audit logs of corruption and remediation events will be gathered and made available in reports, if possible
- Format migrations may be completed on a case-by-case basis
- Software/system environment may be preserved to aid in recoverability of data
Page last modified August 11, 2020
[The general thoughts around this section were adapted from a document the University of Wisconsin - Madison created.]