Digital Preservation at CSUN University Library

The following preservation strategy is presented as a summary of workflows used to secure the acquisition, migration, transfer, storage, and access of digital and digitized archival materials. This summary maps to the NDSA levels of preservation for the following functional areas.

Storage:  Redundant physical locations where preservation files and metadata or stored to ensure records are accessible and secure.

Integrity: A set of protocols and audits such as fixity checks (checksums and digital signatures) and format validations that ensure the trustworthiness of digital objects through evidence that digital records and their associated files are unaltered, reliable, and not corrupt.

Control: The designation and monitoring of human and software agents to access, process, and manage digital and digitized records.

Metadata: Data about a digital resource that is stored in a structured form suitable for machine processing. Metadata can reflect the administrative, descriptive, technical, and preservation information regarding a digital object. It is often embedded within a digital file, kept as a sidecar text file, or managed within a collections and the preservation management system.

Content: The documentation, verification, and monitoring of digital file characteristics to protect against obsolescence and facilitate user access.

Documentation

1. Using inventories for unprocessed audiovisual and born-digital media, digital services personnel document migration and acquisition activities, noting physical condition, conservation activities, and topical descriptions to assist archival processing.
2. Physical carriers of the media are photographed to capture metadata which are added to the inventories to assist with archival descriptions.
3. Media are visually assessed to determine the method of migration/acquisition, conservation (if needed) and agents required for preservation.

NDSA Tasks

• Control:  Levels 1-2
• Metadata: Levels 1-2
• Content:  Levels 1

Format Migrations

Audiovisual formats are migrated in-house for selected audio and videotape. We are currently unable to capture 1’’, 2’’, or ½’’ inch tape, PAL or SECAM videotape, or any motion picture film at this time. If any of these formats are found in a collection, they are sent to a local vendor for digitization as needed once funding is secured.  

1. Digital services personnel provide preservation protocols for textual and visual media upon request to mediate degradation or as part of digital projects and initiatives.
2. Basic conservation treatment is applied to most media on an as-needed basis. This includes rehousing, baking, cleaning, and lubrication. 
3. Digitally reformatted files receive baseline checksums to support integrity monitoring.
4. Digitally reformatted files are embedded with additional metadata to identify titles, creators, source, dates, copyright, and technical metadata.
5. Migrated files are redundantly stored until ingest into the preservation management system.

Preservation and Access Levels

With consideration to use and need, media are captured and encoded with file specification standards outlined by FADGI Audiovisual Working Group, Library of Congress, and other applicable organizations to produce the following preservation and access files.

Archival (Preservation) Master: Lossless or virtually lossless media captured for long-term preservation at high resolution with no other adjustments to represent the highest quality derivative.

Production Master: Captured as needed for long-term preservation at high resolution. The file may be lossless or virtually lossless but may contain adjustments or alterations to improve the user experience. For example, filters used to enhance the fidelity (usability) of an image or other media file.

Access file: Compressed, reformatted, or otherwise resized derivative for online use.

NDSA Tasks

• Storage: Level 1
• Integrity: Levels 1-2
• Control: Levels 2-3
• Metadata: Levels 2-3
• Content: Level 2

Data Acquisition

Born-digital data are acquired to preserve their original state without alteration to ensure the capture of associated technical metadata; original order of the files; and establish a file integrity regimen. 

1. Original bitstreams (disk images) are captured from data storage media for which an original byte-for-byte copy is desired and/or manageable as a preservation format within our storage infrastructure. Otherwise, records are packaged for transfer and protected against overwriting.
2. Virus checks are applied to acquired born-digital media and quarantined when positive.
3. Checksums and format validations provide baselines for integrity monitoring.
4. Original data storage media are scanned for personally identifiable information (PII).
5. Additional acquisition reports are preserved with acquired data as needed for documentation.
6. Acquired files are redundantly stored until ingest into the preservation management system.

NDSA Tasks

• Storage: Level 1
• Integrity: Levels 1-2
• Control: Levels 2-3
• Metadata: Levels 2-3
• Content: Level 2

Long-Term Storage

The completion of documentation, migration, and/or data acquisition procedures facilitate archival descriptions and prepare digital objects for ingest into the preservation management system for long-term storage.

1. Settings for file normalization for derivative access are made prior to (common formats), or at the time of ingest (proprietary formats).
2. Ingests include subsequent layers of integrity checks through checksums and format validations.
3. Format obsolescence is monitored within the preservation management system at regular intervals. Files are updated (normalized) to new formats as needed.
4. Data are redundantly stored across multiple locations within the preservation management system.

NDSA Tasks

• Storage: Levels 3-4
• Integrity: Levels 3-4
• Control: Level 4
• Metadata: Level 4
• Content Levels 3-4

Access

Unless published online, digital records are served to researchers remotely via authenticated online access provided through the preservation management system, or alternatively made available through secure online platforms.