ISO/IEC INTERNATIONAL STANDARD 20919 Second edition 2021-07 Information technology - Linear tape file system (LTFS) Format specification Technologies de I'information - Speécification du format de systeme de fichier a bande magnétique Reference number ISO/IEC 20919:2021(E) tso EC @IS0/IEC2021 IS0/IEC 20919:2021(E) COPYRIGHT PROTECTED DOCUMENT IS0/IEC2021 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or IsO's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone:+4122 749 0111 Email: [email protected] Website:www.iso.org Published in Switzerland i @ IS0/IEC 2021 - All rights reserved IS0/IEC 20919:2021(E) Foreword ISo (the International Organization for Standardization) and IEc (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISo or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity ISsO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. The procedures used to develop this document and those intended for its further maintenance are described in the IsO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types ofdocument should noted (see www.iso.org/directives or www.iec.ch/members experts/refdocs). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISo list of patent declarations received (see www.iso.org/patents) or the IEc list of patent declarations received (see patents.iec.ch). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation of the voluntary nature of standards, the meaning of Iso specific terms and expressions related to conformity assessment, as well as information about Iso's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT),see www.iso.org/iso/foreword.html. In the IEC, see www.iec.ch/understanding-standards. This document was prepared by the Storage Networking Industry Association (SNIA) (as Linear Tape File System (LTFS) Format Specification, Version 2.5) and drafted in accordance with its editorial rules. It was adopted, under the JTC 1 PAS procedure, by Joint Technical Committee ISO/IEC JTC 1, Information technology. This second edition cancels and replaces the first edition (IS0/IEC 20919:2016), which has been technically revised. The main changes compared to the previous edition are as follows: Volume Advisory Locking a method of marking a volume as locked against future modification; Percent Encoding - - method of including previously reserved characters in names of files and directories; Incremental Indexes - a method of recording a smaller index containing only changes since the last index; File hashes - a method of recording fils hash information in the index in an interchangeable manner; Open For Write - a method of noting files in the index which were still open at the time the index is written to tape. Any feedback or questions on this document should be directed to th