Digital preservation practices

Pocket Archive is not a full end-to-end digital preservation solution, but it allows an administrator to build one using simple, effective, and free tools.

Since "Digital preservation" is a very loaded term, with many different schools of thought interpreting it in a variety of ways, it may be good to begin stating what we intend with digital preservation in this context.

A "pocket" digital preservation strategy includes:

  1. Digitizing physical artifacts, and/or producing born-digital contents, according to widely accepted standards for preservation-worthy file formats and quality;
  2. Effective cataloging through mindful metadata entry;
  3. Storage of files and metadata on a reliable support;
  4. Maintaining multiple copies of the archive on multiple platforms;
  5. Use of an archival system based on stable technologies;
  6. Planning an exit strategy from the current system;
  7. Strategic use of fixity checking to verify data integrity.

These points are explained in detail in their individual pages, with pointers on how to achieve them with Pocket Archive.

Features not supported by design

Some practices and features usually offered by digital preservation systems have been purposefully excluded from the Pocket Archive design:

Versioning

Pocket Archive does not keep previous versions of data or metadata. This is a deliberate choice, even though many use versioning as an added safeguard against human error.

While recognizing the usefulness of versioning, the decision was made not to support this feature as it is complicated to implement and expensive to maintain. The vast majority of times, versions are created for trivial changes, making the writing and retrieval of data slower, and increasing the size of the database and file store significantly.

Pocket Archive relies on its users to be mindful about data entry, especially bulk updates, and on the fact that many mistakes made in bulk operations can be reversed with another bulk operation, which is not always easy to do, but still easier and less expensive than maintaining a versioning system that grows indefinitely.