ISO/IEC DIS 20919
Information technology — Linear tape file system (LTFS) Format specification
|Publication Date:||14 April 2020|
|ICS Code (Magnetic storage devices in general):||35.220.20|
This document defines the LTFS Format requirements for interchanged media that claims LTFS compliance. Those requirements are specified as the size and sequence of data blocks and file marks on the media, the content and form of special data constructs (the LTFS Label and LTFS Index), and the content of the partition labels and use of MAM parameters.
The data content (not the physical media) of the LTFS format shall be interchangeable among all data storage systems claiming conformance to this format. Physical media interchange is dependent on compatibility of physical media and the media access devices in use.
NOTE: This document does not contain instructions or tape command sequences to build the LTFS structure.
This document describes version 2.5.0 of the Linear Tape File System (LTFS) Format Specification.
The version number for the LTFS Format Specification consists of three integer elements separated by period characters of the form M.N.R, where M, N and R are positive integers or zero. Differences in the version number between different revisions of this specification indicate the nature of the changes made between the two revisions. Each of the integers in the format specification are incremented according to Table 1.
NOTE 1: When any element of the specification version number is incremented, all sub-ordinate elements to the right are reset to zero. For example, if the version is 1.0.12 and N is incremented to 1, then R is set to zero resulting in version 1.1.0.
NOTE 2: The first public version of this document used version number 1.0. This value should be interpreted as equivalent to 1.0.0 in the version numbering defined in this document.
The result of comparison between two LTFS version numbers MA.NA.RA and MB .NB .RB is defined in
Recorded media claiming conformance to this format shall be in a consistent state when interchanged or stored. See Section 4.1.4.
Any implementation conforming to this specification should be able to correctly read Label and Index structures from all prior versions of this specification and write Label and Index structures conforming to the descriptions in this document. The current Label and Index structures are defined in Section 8 Label Format and in Section 9 Index Format.
NOTE: Where practical, any implementation supporting a given version value for M should endeavor to support LTFS volumes with version numbers containing higher values for N and R than those defined at the time of implementation.