SANS 23868-2008 Document management - Monitoring and verification of information stored on 130 mm optical media《文件管理 存储在130mm光学媒体上信息的监测和验证》.pdf

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1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22216-1 SANS 23868:2008 Edition 1 ISO 23868:2008 Edition 1SOUTH AFRICAN NATIONAL STANDARD Document management Monitoring and verification

4、of information stored on 130 mm optical media This national standard is the identical implementation of ISO 23868:2008 and is adopted with the permission of the International Organization for Standardization. Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria

5、 0001 Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 23868:2008 Edition 1 ISO 23868:2008 Edition 1 Table of changes Change No. Date Scope National foreword This South African s

6、tandard was approved by National Committee SABS TC 171, Document management applications, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in November 2008. This standard may only be used and printed b

7、y approved subscription and freemailing clients of the SABS. Reference number ISO 23868:2008(E) ISO 2008INTERNATIONAL STANDARD ISO 23868 First edition 2008-10-15 Document management Monitoring and verification of information stored on 130 mm optical media Gestion de documents Surveillance et vrifica

8、tion de linformation stocke sur des supports optiques de 130 mm SANS 23868:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 23868:2008(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing po

9、licy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobes licensing policy. The ISO Centra

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11、 to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2008 All rights reserved. Unless otherwise specified, no part of this pu

12、blication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Ge

13、neva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2008 All rights reservedSANS 23868:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 23868:2008(E) ISO 2008 All r

14、ights reserved iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a su

15、bject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (

16、IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical commi

17、ttees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not b

18、e held responsible for identifying any or all such patent rights. ISO 23868 was prepared by Technical Committee ISO/TC 171, Document management applications, Subcommittee SC 1, Quality. SANS 23868:2008This standard may only be used and printed by approved subscription and freemailing clients of the

19、SABS.ISO 23868:2008(E) iv ISO 2008 All rights reservedIntroduction Many organizations now use optical media for long-term storage of information. It is assumed that a disk selected for recording has already been qualified for that purpose. It is therefore important to be able to verify that data hav

20、e been recorded correctly and remain readable for the required amount of time. Previous ISO Standards clearly specified requirements for interchange, and methods for predicting the lifetime of optical media but did not contain methods for validation of the quality of written data. Longevity is limit

21、ed both by media degradation and by technology obsolescence. Interchange needs to be regularly verified to assure that information on existing recorded media will continue to be recoverable. Users can have a maintenance policy that protects disks against unanticipated failure or use, such as by maki

22、ng one archival copy, another to function as a backup or master, and another for routine access. Hardware support lifecycles typically vary between 5 years to 10 years and technology lifecycles usually end after 20 years. Consequently, recordings that require a longer lifecycle might have to be tran

23、sferred to upgraded platforms every 10 years to 20 years. Optical media for long-term storage should be evaluated. Significant longevity differences can exist for disks from different media manufacturers and also between disks from the same media manufacturer. Degradation can be more rapid for disks

24、 of very poor initial quality than for high quality recordings. Disks with an initially poor quality do not offer sufficient headroom to avoid reaching the unrecoverable error threshold before the next scheduled inspection, which for archival disks is to be avoided. This means that a disk of high in

25、itial recorded quality that maintains this condition for life is expected to have superior longevity. Powerful cyclic redundancy check (CRC) error correction systems that are embedded in the disk and utilized by the drive can mask degradation. In the absence of drive standards, functionality does no

26、t allow the user to verify, in a simple manner, the quality of information recorded on a particular disk. Methods described in this International Standard specify a quality control policy that can non-destructively identify degradation, and thereby support timely and effective corrective action. SAN

27、S 23868:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.INTERNATIONAL STANDARD ISO 23868:2008(E) ISO 2008 All rights reserved 1 Document management Monitoring and verification of information stored on 130 mm optical media 1 Scope This Inter

28、national Standard specifies test methods to determine the quality of data on recorded media and provides specifications enabling end-user organizations to monitor data quality and ongoing conformance with the error limits required for its class identified by the manufacturer of the drive/media. This

29、 International Standard defines error rate monitoring capabilities and procedures associated with 130 mm optical media while being used in a production environment to ensure that data are still readable throughout the expected life of the media. 2 Normative references The following referenced docume

30、nts are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 12651, Electronic imaging Vocabulary ISO/IEC 17345, Information technology D

31、ata interchange on 130 mm rewritable and write once read many ultra density optical (UDO) disk cartridges Capacity: 30 Gbytes per cartridge First generation ISO/IEC 11976, Data interchange on 130 mm rewritable and write-once-read-many ultra density optical (UDO) disk cartridges Capacity: 60 Gbytes p

32、er cartridge Second generation 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 12651, ISO/IEC 17345, ISO/IEC 11976, and the following apply. 3.1 end-of life EOL loss of interchange whereby information cannot be reliably retrieved 4 Test method 4.1 Ge

33、neral The method specified in this International Standard to determine the quality of data on recorded media is based on a knowledge of the error correcting codes used to correct for inevitable media defects and the deterioration during normal life of the media. At the time of writing, the data shou

34、ld be verified by the writing system. During this verification process, the level of defects shall be checked and only data which require a small percentage of the error correction capability shall be accepted by the writing system. This International Standard defines a method for subsequent analysi

35、s of the remaining error correction capability when the SANS 23868:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 23868:2008(E) 2 ISO 2008 All rights reservedmedia are read on a reference drive. In addition, the performance of the serv

36、os on the media shall be checked to determine if any unacceptable media distortion has occurred. 4.2 Calibration of test drive The drive manufacturer provides reference disks, that have been checked on calibrated equipment. These media shall be provided with a test report documenting the acceptable

37、range of results that shall be obtained when scanned on a drive to be used for archive data scanning. Any drive used to perform the media quality tests shall pass the check with reference media. 4.3 Test parameters The remaining error correction capability and servo performance of the media that are

38、 scanned shall be measured using a media scan. In order to keep the scan to a manageable time, a percentage of the surface shall be scanned. During the scan of a disk, the following operations shall be performed. a) The surface of the media shall be scanned to determine the location of written secto

39、rs. b) A minimum of every tenth track of user written data shall be read and the number of errors in each code word calculated so as to ensure that there is sufficient remaining correction capability in the written sectors. The user may select to scan 100 % of the data depending on the value attribu

40、ted to the content of the media. c) If 75 % of the available error correction capability in any sector tested is required to recover valid data, the media shall be reported as being at risk. In this case, the first measure shall be to clean the media according to the manufacturers instructions and t

41、o rescan for defects. If the same error is reported, the data should be migrated within 2 years of the date of testing. d) The servo channels shall be monitored to verify that none of the allowable thresholds are exceeded, for example due to surface dust or scratches. The maximum servo disturbances

42、are defined in the relevant ISO specification for the media type (ISO/IEC 17345, ISO/IEC 11976). In this case, the first measure shall be to clean the media according to the manufacturers instructions and to rescan for defects. If the same error is reported, the data should be migrated within two ye

43、ars of the date of testing. e) The sector addresses shall be checked to ensure that at least one ID field in every sector is readable without errors. If this condition is not met, the media shall be reported as being at risk. In this case, the first measure shall be to clean the media according to t

44、he manufacturers instructions and to rescan for defects. If the same error is reported, the data should be migrated within two years of the date of testing. f) The remaining spares area shall be checked to ensure that the relocation rate is acceptable. Less than 50 % of the spares allowed shall have

45、 been used. The spares allowed shall be allocated in proportion to the percentage of the user area written. If this condition is not met, the media shall be reported as being at risk. In this case, the first measure shall be to clean the media according to the manufacturers instructions and to resca

46、n for defects. If the same error is reported, the data should be migrated within two years of the date of testing. 4.4 Test set-up Before testing a media cartridge, the drive to be used shall be calibrated using reference media supplied by the drive manufacturer. The cartridge to be tested should be

47、 inspected for physical damage but no attempt should be made to clean the media surface. In general, media cleaning is detrimental to performance unless carried out using the correct materials to a specification. Only in the event of a disk cartridge failing the scan, should the media be cleaned. Se

48、e informative Annex A for recommendations on disk cleaning. Disk cleaning should only be performed using the recommended disk cleaner and cleaning fluid supplied by the media vendor. On no account shall the user disassemble the disk cartridge. SANS 23868:2008This standard may only be used and printe

49、d by approved subscription and freemailing clients of the SABS.ISO 23868:2008(E) ISO 2008 All rights reserved 3 4.5 Procedure The tester shall use a software application, certified by the drive manufacturer to accurately identify media errors on certified media to verify certified media on a drive connected to a computer via a computer interface. The tester shall be able to enter a disk serial number and this shall be added to the test file generated by the test. Before testing media, verify the system by checking the reference m