n.the practice of copying records from one physical carrier to another for preservationCook 1991b, 36At any stage in the appraisal process, archivists can consider requesting that the institution convert the records or key information in them to electronic, micrographic or optical disk formats as an alternative to collecting extensive series of bulky paper records, or to solve conservation and perhaps privacy issues. They can also consider alienating all or some of the records from the archives of first jurisdiction to another repository. However, these are preservation or political issues, not appraisal options. The records in such instances have already been appraised as having permanent value before the practical and preservation concerns of actual transfer and acquisition are considered. Unless such media migration has been done by the creating agency in the course of its normal business, however, archives will normally find that the conversion costs outweigh the storage ones, and only a small portion of their holdings will be so treated.Caplan 2004, 39Once we decided to accept all formats, however, we realized we could not guarantee that we would have an action plan for each archived format ready in time to do forward migration on it when necessary. This led us to offer two levels of preservation treatment, bit-level and full. Bit-level preservation means we will keep a file safe through secure storage and backup, media refreshment, media migration, and data security measures. Full preservation includes bit-level preservation and a promise to do file migration and/or normalization when called for. Full preservation treatment will be available only for formats with completed action plans.Grimard and Pagé 2004, 116With regard to records management, the Association of Records Managers and Administrators (ARMA) published a guide to cost indicators; the guide comes with a software program which allows users to calculate the cost of various operations such as storage of active and inactive paper and microform records, media migration (paper-to-microform, paper-to-electronic format, microform-to-electronic format), destruction of paper records and microforms, retrieval of information on paper and microform, and in electronic formats.Fleischhauer and Bradley 2019, A-4, fn. 5In the field of digital preservation, the term migration is used in two ways. Media or system migration refers to the movement of digital files from obsolete data-storage media or an obsolete data-management system to new media or a new system. Media migration is sometimes called physical migration and media refreshment. In this form of migration “the bits do not change.” In contrast, format migration, also known as logical migration, refers the movement of a content item from one format to another: “the bits do change.”Baxter and Tadic 2020, 36Media migration. All data must be stored on physical media, whether spinning disk, SSDs, or LTO data tape. Media doesn’t last forever; it fails, and becomes obsolete. Therefore, files must be migrated (refreshed) to new storage media over time.
Analog media migration may include a change of format; in digital preservation, the change of physical storage medium is deliberately bit-for-bit duplication.