Archivetar

Archivetar is a term used in digital archiving to describe tar-based archives prepared for long-term preservation. It combines the general tar archive format with structured preservation metadata to improve accessibility, integrity, and provenance over time.

A typical archivetar package consists of a tarball containing the objects and, optionally, a metadata bundle that documents provenance, file formats, checksums, and events (creation, modification, transfer). Preservation metadata commonly follows standards such as PREMIS for the data's provenance and events and METS for structural metadata; checksums are recorded in a manifest file. Some implementations store metadata in sidecar files or as extended attributes.

Usage and workflow: create the tarball, generate checksums for each file, assemble a manifest, and, where possible, sign the package. Examples: tar -czf archive.tar.gz data/; sha256sum archive.tar.gz > archive.sha256; store both in a repository with a metadata descriptor.

Advantages and limitations: Archivetar is portable and broadly supported by common tooling, aiding long-term preservation and transfer. Metadata standards enable future discovery and interoperability. However, tar lacks intrinsic metadata semantics and cryptographic integrity by itself, so archivetar relies on external metadata and integrity verification and may require additional tooling for robust long-term preservation and emulation.

See also: Tar (archiving), PREMIS, METS, digital preservation, checksums.