Digital preservation
Digital preservation is a combination of infrastructure and services which collectively guarantee the availability of the National Library’s digital archive for future generations.
Digital preservation ensure that digital material is archived and preserved exactly as it was received, and that data over time can be read, and understood, as closely as possible to the original expression.
Digital preservation at the National Library is based on the following principles:
- Ensure that digital preservation is done in a sustainable way
Digital preservation is a resource-intensive process. Be deliberate when selecting which files to preserve and in what format. Choose storage technologies that are environmentally friendly and energy efficient. - Use well-documented and open file formats wherever possible
This increases the likelihood that we will be able to read and understand and utilize the file now and in the future. Good format choices make it easier to manage the file over time. Proprietary and undocumented file formats can have short and unpredictable life spans. - Preserve the original file
With future format conversions, there is always a risk that the content will be changed in an undesirable way, either deliberately or through errors in the conversion process. Preserving the original file means that it will always be possible to redo this process. In this context the original file refers to the file as it was originally preserved. - Analyze files that are to be preserved
Generate checksums as early as possible to verify that the file is not modified in handling and retains integrity over time. Identify and validate the file type to reveal its current state, and to enable management over time. - Maintain sufficient metadata to ensure that the files are identifiable and retrievable
This information should ensure that the files can be managed, understood, used and retrieved in the future, regardless of the external environment.- Technical metadata, such as information about file format, file size, structure, etc. This provides detailed knowledge of the technical composition of the file. It strengthens the integrity of the collection and improves the quality of planned preservation activities, such as format conversion, etc.
- Administrative metadata, such as the source of the files, how they were created and processed, rights information and other provenance. This provides knowledge about the origin and history of the files and helps to establish the credibility of the content.
- Descriptive metadata, such as synopses of plot, content descriptions, information about creators, credits, etc. These describe the intellectual content of the files and make the content identifiable and retrievable.
- Use a standardized format to package files for preservation
Standardization enables content and metadata to be exchanged efficiently and in a consistent way, regardless of the type of material or depositor. In the NLN, the eArchiving standard is used. The use of established standards enables the use of documentation and existing tools. - Standardise documentation preservation activities
This strengthens the integrity of the collection and improves the quality of planned preservation activities related to format conversion, etc. The NLN uses PREMIS for this. - Files should be readable and understandable in the present
If it is not possible to open the file in the present, it is unlikely that it will be possible in the future. This requires monitoring of file formats and playback platforms in order to take the necessary measures. Old and outdated file formats are converted to new open formats as needed. - Ensure that a file is stored in multiple instances, on different storage technologies and in different geographical locations
Multiple instances of a file reduce the likelihood of material being lost due to technical or physical events affecting individual copies.