Category: Digital Preservation

Media Migration

Also known as: media or system migration, system migration

Simply put

Media migration is the process of moving digital files off storage media or a data-management system that is becoming obsolete and onto newer media or a newer system. It is typically done to keep digital records accessible and usable as older technology and formats fall out of use. It is not the same as making routine backup copies, though it may involve copying as part of the transfer.

Formal definition

In a recordkeeping and digital preservation context, media migration refers to the movement of digital files from obsolete or failing data-storage media, or from an obsolete data-management system, to new media or a new system. It is generally undertaken to mitigate the risks of media degradation, hardware and software obsolescence, and loss of access, thereby supporting the continued usability of digital records over time. Depending on organizational policy and the preservation objectives, migration should be planned and documented to protect the authenticity, integrity, and reliability of the records being moved, since transfer between media or systems can introduce risks of alteration or loss. Media migration is distinct from format migration or conversion (which changes the file format rather than the storage medium or system) and from routine backup; it also falls outside broader, unrelated senses of 'migration' concerning the movement of people, which appear in some sources but are not relevant to this recordkeeping term.

Why it matters

Digital records depend on the storage media and management systems that hold them, and both are subject to physical degradation and technological obsolescence over time. As older media wear out and as the hardware and software needed to read them fall out of common use, records stored on them can become difficult or impossible to access. Media migration is one of the principal strategies used to address this risk, allowing organizations to keep digital records usable as the underlying technology changes.

Because migration involves moving files between media or systems, the transfer itself can introduce risks of alteration or loss. This is significant from a recordkeeping perspective, where the authenticity, integrity, and reliability of a record are what distinguish it from mere information or a casual copy. If migration is carried out without planning and documentation, an organization may preserve access to content while inadvertently weakening the evidential qualities that make a record trustworthy. For this reason, migration in a preservation context is treated as a controlled activity rather than a purely technical one.

It is worth noting that 'migration' carries an unrelated everyday meaning concerning the movement of people, which appears widely in other sources. That sense is outside the scope of this term. In recordkeeping, media migration refers specifically to the movement of digital files off obsolete media or systems and onto newer ones.

Who it's relevant to

Records managers

Those responsible for controlling records across their lifecycle need to plan migration so that records remain usable as media and systems age, while ensuring the transfer does not compromise the authenticity, integrity, or reliability of the records being moved.

Digital preservation practitioners

Practitioners tasked with keeping digital materials accessible over the long term rely on media migration as one strategy for mitigating media degradation and hardware and software obsolescence, and are typically concerned with documenting the process to preserve evidential value.

Archivists

Archivists managing digital holdings may use media migration to sustain access to records transferred for continued preservation, and need to distinguish it from format migration and from routine backup when defining preservation approaches.

IT and storage administrators

Staff who operate storage media and data-management systems often carry out the technical transfer of files. Their work benefits from coordination with records and preservation staff so that migration meets recordkeeping requirements and not only operational or capacity goals.

Information governance officers

Those setting policy and managing risk across the organization have an interest in ensuring that migration is governed, planned, and documented, since uncontrolled transfers can undermine the trustworthiness of records the organization may need as evidence.

Inside Media Migration

Media Migration

The process of transferring records or data from one storage medium to another, often to address the physical degradation, technological obsolescence, or end-of-life status of the original carrier. It is primarily concerned with preserving the continued accessibility and usability of records over time, and is typically distinguished from format migration, which addresses the obsolescence of file formats rather than the storage carrier itself.

Source and Target Media

Media migration involves a source medium (the carrier holding the records prior to transfer, such as magnetic tape, optical disc, or an older disk array) and a target medium (the newer or more sustainable carrier receiving the records). The suitability of a target is often assessed against expected longevity, supportability, and organizational infrastructure, though what qualifies as appropriate depends on organizational policy and context.

Integrity and Authenticity Preservation

Because migrated records should remain trustworthy evidence of activity, the process typically seeks to preserve the properties that make something a record, including authenticity, reliability, integrity, and usability. Verification techniques such as checksums or fixity checks are often used to confirm that the transferred content matches the source, though the specific methods applied depend on the systems and standards an organization adopts.

Metadata and Contextual Continuity

Migration generally aims to carry forward associated metadata and contextual information so that records remain understandable and usable in their new environment. Loss of metadata during transfer can undermine the evidential value of a record even where the primary content survives intact.

Relationship to Disposition

Media migration is an ongoing preservation and continuity activity rather than a disposition decision in itself. It should be distinguished from disposition actions such as transfer, destruction, or permanent preservation, although migration is often performed in support of records identified for long-term or permanent retention.

Documentation and Audit Trail

A record of migration activity, including what was migrated, when, by whom, and with what verification results, is commonly maintained to support accountability and to demonstrate that integrity was preserved. The extent and formality of such documentation typically depend on organizational policy and applicable requirements.

Common questions

Answers to the questions practitioners most commonly ask about Media Migration.

Is media migration the same as making a backup copy of records?

No. Backups are typically short-term, operational copies created to enable recovery after data loss or system failure, and they are usually cycled and overwritten on a schedule. Media migration, by contrast, is the deliberate transfer of records from one storage medium or carrier to another to sustain accessibility and integrity over the retention period, often because the original medium is degrading or becoming obsolete. A backup may preserve bits for a limited window, but it does not by itself address long-term carrier obsolescence, and it is generally not a substitute for a planned migration strategy.

Does migrating records to new media automatically preserve their authenticity and evidential value?

Not automatically. Moving records to fresh media addresses the physical carrier, but authenticity, reliability, integrity, and usability must be actively maintained and demonstrable through the process. Migration can introduce risks such as alteration, loss of metadata, or breaks in the chain of custody if it is not controlled and documented. Whether the migrated records remain trustworthy typically depends on verifying that content and relevant metadata transfer intact, capturing evidence of the migration event, and confirming that the records remain usable in the target environment.

How can we verify that records survived a media migration unchanged?

Verification approaches commonly include comparing the source and target using integrity checks, confirming that expected files and record counts are present, and validating that associated metadata has transferred correctly. Many organizations document the outcome of these checks as part of the migration record. The specific methods appropriate to a given migration depend on the volume, formats, and criticality of the records involved, as well as organizational policy and any applicable requirements.

What should be documented when carrying out a media migration?

It is generally advisable to record what was migrated, when, by whom, the source and target media, the tools or methods used, and the results of any integrity or completeness checks. This documentation supports the chain of custody and helps demonstrate that authenticity and integrity were maintained. The level of detail that is appropriate often depends on the evidential importance of the records and on organizational or jurisdictional expectations.

How does media migration relate to retention and disposition decisions?

Media migration is typically applied to records that must remain accessible for the duration of their retention period or, where applicable, permanently. It is not a reason in itself to retain records beyond their scheduled disposition. Before migrating, organizations often confirm that the records are still required, so that resources are not spent carrying forward material that is already eligible for disposition. Migration and disposition are therefore best coordinated with the retention schedule.

When should an organization plan for media migration?

Migration is often planned proactively, before storage media, formats, or the systems needed to read them become obsolete or begin to degrade, rather than in reaction to a failure. Many organizations monitor the condition and supportability of their storage carriers and the technology environment required to access records, and schedule migration accordingly. The appropriate timing depends on factors such as the expected lifespan of the media, the length of retention periods, and organizational risk tolerance.

Common misconceptions

Media migration and format migration are the same thing.

They address different problems. Media migration moves records to a new storage carrier to counter carrier degradation or obsolescence, while format migration converts records from one file format to another to counter format obsolescence. A single preservation strategy may involve both, but they are distinct activities and should not be conflated.

Copying records to new media automatically preserves them as authoritative records.

A straightforward copy does not guarantee that authenticity, integrity, and usability are maintained. Without verification of the transferred content and preservation of associated metadata and context, the migrated version may lose its evidential value. Migration typically requires controls, not just a data copy.

Media migration is a one-time task completed once records are moved to modern media.

Storage media and the technologies that read them continue to degrade and become obsolete over time, so migration is generally treated as a recurring activity across the lifecycle of long-lived records rather than a single event.

Best practices

Distinguish clearly between media migration and format migration in preservation planning, and address each where relevant rather than assuming one covers the other.

Verify the integrity of migrated content using fixity or checksum techniques appropriate to your systems, and confirm that the target matches the source before retiring the source medium.

Ensure associated metadata and contextual information are migrated alongside the primary content so that records remain authentic, understandable, and usable in their new environment.

Maintain documentation of each migration, including scope, timing, responsible parties, and verification results, to support accountability and to demonstrate that integrity was preserved.

Treat migration as a recurring activity by monitoring the longevity and supportability of current media and planning future migrations before carriers or reading technologies reach end of life.

Align migration decisions with disposition and retention policy, focusing sustained migration effort on records identified for long-term or permanent retention, and confirm requirements against applicable jurisdictional and sector obligations.