Linear Tape File System (LTFS)

SNIA's Linear Tape File System (LTFS) Technical Work Group is focusing technical efforts on the development of an architecture that is related to the on-tape format for LTFS. The architecture also produces a comprehensive set of specifications ensuring a consistency of interface standards across LTFS related efforts.

LTFS refers to both the format of data recorded on magnetic tape media and the implementation of specific software that uses this data format to provide a file system interface to data stored on magnetic tape.

LTFS provides an industry standard format for recording data on modern magnetic tape.

This standard allows for:

  • File system implementations using tape
  • User-friendly access to tape data using familiar tools and interfaces
  • Cross-platform and cross-vendor interoperability for tape - Non Proprietary
  • A standard for data interchange
  • Open markets
  • Ensures multivendor products
  • Data sharing

LTFS Format Specification

The LTFS specification became part of the SNIA family of standards in 2012 donated by a vendor to SNIA as a vendor specific proprietary standard to become an open SNIA standard.

The LTFS Format is particularly suited to these usages:

  • Data export and import.
  • Data interchange and exchange.
  • Direct file and partial file recall from sequential access media.
  • Archival storage of files using a simplified, self-contained or “self-describing” format on sequential access media.

The LTFS Format has these features:

  • An LTFS Volume can be mounted and volume content accessed with full use of the data without the need to access other information sources.
  • Data can be passed between sites and applications using only the information written to an LTFS Volume.
  • Files can be written to, and read from, an LTFS Volume using standard POSIX file operations.

LTFS Bulk Transfer Standard

The LTFS Bulk Transfer standard defines a method by which a set of files, directories and objects from a source system can be transferred to a destination system. The bulk transfer of large quantities of data is well suited for LTFS due to the economic and environmental characteristics of tape.

Building on top of the LTFS format, a standardized method for transferring data is defined that provides many advantages such as:

  • Provides a uniform way to initiate and accept transfers
  • Defines a manifest of which files are to be transferred, which communicates intent to transfer
  • Instructs how the files should be merged into the destination namespace
  • Facilitates the verification of the integrity and completeness of the transfer
  • Defines error handling and recovery behaviors
  • A recommended method for bulk transfers to/from or between cloud storage.

The LTFS Bulk Transfer standard is specifically targeted for the following use cases:

  • An enterprise needs to transfer a large volume of data to or
  • from a remote location
  • An enterprise needs to update or synchronize a subset of
  • data stored at a remote location
  • An enterprise needs to transfer a large volume of data to a
  • second enterprise, public, or private cloud
  • An enterprise needs to transfer a large volume of data from
  • a public or private cloud
  • An enterprise needs to transfer a large volume of data from
  • one public or private cloud to a second public or private
  • cloud

Current LTFS Technical Work Group Projects

  • LTFS Compliance Test Specification - This specification defines the test cases to be executed by the LTFS adaptor to validate the compliance of an implementation, the file system software and the produced media, with LTFS Format Specification.   The goal is to improve the interchangeability of LTFS formatted tapes between different implementations.
  •  LTFS Tape Image Format Specification- This specification defines the data structure of a file image for a magnetic tape written by the LTFS implementation, analogous to *.iso file format for optical disc storage.

Documents and Resources

Vendor Extended Attributes

The LTFS format allows for vendor specific extended atrributes. It is recommended that a vendor (a company, organization, or technology standard) reserve their name. Refer to Appendix C of the Format Specification.

Registered Vendor Names

  • CDMI
  • HP
  • HPE
  • IBM

Get Involved

If you are interested in becoming involved with the LTFS Technical Work Group, please contact