1、Information technology Digitally recorded media for information interchange and storage Data migration method for DVD-R, DVD-RW, DVD-RAM, +R, and +RW disks Technologies de linformation Supports enregistrs numriquement pour change et stockage dinformation Mthode de migration de donnes pour disques DV
2、D-R, DVD-RW, DVD-RAM, +R, et +RW ISO/IEC 2013 INTERNATIONAL STANDARD ISO/IEC 29121 Second edition 2013-11-01 Reference number ISO/IEC 29121:2013(E) ISO/IEC 29121:2013(E)ii ISO/IEC 2013 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2013 All rights reserved. Unless otherwise specified, no p
3、art 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 ISOs member
4、body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO/IEC 29121:2013(E) ISO/IEC 2013 All rights reserved iii Contents Page Foreword iv Introduction
5、 v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 2 4 Test methods . 3 4.1 Test parameters 3 4.2 Test Drive . 4 4.3 Test area 4 5 Test result evaluation 4 5.1 Initial performance test result evaluation . 4 5.2 Periodic performance test result evaluation . 5 6 Test interval . 6 7 Pre
6、vention of deterioration 6 Annex A (informative) Causes of deterioration for DVD-R, DVD-RW, DVD-RAM, +R, and +RW disks 7 Annex B (informative) Recommendations on handling, storage and cleaning conditions for DVD-R, DVD-RW, DVD-RAM, +R, and +RW disks . 9 Annex C (informative) Relation between BER and
7、 PI SUM 8 11 Annex D (informative) Guideline for adjustment of the estimated lifetime to higher stress conditions 12 Annex E (informative) Calculation for B migLife using B 50Life and B 5Life .14 Annex F (informative) Guideline of test interval and migration 16 Annex G (informative) Test area.20 Bib
8、liography .21 ISO/IEC 29121:2013(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 In
9、ternational Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liai
10、son with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of the joint tech
11、nical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. Attention is
12、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 the identifying any or all such patent rights. ISO/IEC 29121 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcomm
13、ittee SC 23, Digitally recorded media for information interchange and storage. This second edition cancels and replaces the first edition (ISO/IEC 29121:2009), of which has been technically revised.iv ISO/IEC 2013 All rights reserved ISO/IEC 29121:2013(E) Introduction Many organizations now use opti
14、cal disks 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 has been recorded correctly and remains readable for the required amount of time. Previous Internatio
15、nal Standards clearly defined requirements for interchange, but did not contain requirements for longevity. Longevity is limited both by disk degradation and by technology obsolescence. Interchange shall be regularly verified to assure that information on existing recorded disks will continue to be
16、recoverable. Users can have a maintenance policy that protects disks against unanticipated failure or use, such as by making one copy, another to function as a backup or master, and another for routine access. Hardware- support life cycles typically vary between five to ten years, and technology lif
17、ecycles usually end after 20 years. Consequently, recordings that require a longer lifecycle may have to be transferred to upgraded platforms every ten to thirty years. Optical disks for long-term storage should be evaluated. Significant longevity differences can exist for disks from different manuf
18、acturers and even between disks from the same manufacturer. It is preferable that disks selected for long-term preservation should have a long estimated lifetime, which can be estimated according to ISO/IEC 16963. Disks with initially poor quality do not offer sufficient headroom and can reach the u
19、nrecoverable-error threshold before the next scheduled inspection, which is to be avoided for long-term data storage. This means that a disk of high initial recorded quality that maintains this condition for life is expected to have superior longevity. Because read data are corrected by an error-cor
20、rection decoder, it is impossible to detect degradation without detecting the raw error rate or raw error number. The raw error can be detected with a standard test drive. The quality of the disk can be specified as the number of erroneous inner-parity detections with DVD-R, DVD-RW, +R, and +RW disk
21、s. The quality of a DVD-RAM disk is defined instead by its byte error rate. Deterioration can be monitored by checking the raw error numbers and shall continue to be monitored. Methods described in this International Standard define a quality-control policy that can non-destructively identify degrad
22、ation, and thereby support timely and effective corrective action. DVD-R, DVD-RW, DVD-RAM, +R, and +RW disks are based on the technology now widely known as DVD in the market. This entails the use of red laser diodes, two 0,6-mm thick substrates bonded together by an adhesive layer to protect the re
23、cording layer from dust, write-once (DVD-R, +R) or phase-change recording layers (DVD-RW, DVD-RAM, +RW), and a 0,60 or 0,65 NA objective lens to ensure good spatial margins required for a professional data preservation. Disks having dual recording layers with a spacer between them are used in additi
24、on to those with a conventional single recording layer. ISO/IEC 2013 All rights reserved v Information technology Digitally recorded media for information interchange and storage Data migration method for DVD-R, DVD-RW, DVD-RAM, +R, and +RW disks 1 Scope This International Standard specifies a data
25、migration method for long-term data storage. According to the standard, manufacturers are able to construct storage systems that use DVD-R, DVD-RW, DVD-RAM, +R, or +RW disks for information storage. A user of the storage system can select disks with sufficient longevity potential, on the basis of an
26、 initial performance test, and can continuously monitor the potential for retrieving data from those disks on the basis of periodic performance test. These tests are to establish a practical estimate of the retrievability of the recorded data on a disk without producing uncorrectable errors, in resp
27、onse to time at controlled storage conditions to produce accelerated aging. Digital data can be migrated to a next new disk without loss from the present disk as long as data errors are completely corrected before and during the migration, and provided copying of the data is allowed. The methodology
28、 for data migration is intended to be applied to disks with longer storage lifetime. It is recommended to use disks with estimated life time is given as a mean value and a standard deviation as specified in ISO/IEC 16963. If the estimated lifetime of the disks is known, users can determine a test in
29、terval according to the estimated lifetime. If the estimated lifetime is known as a mean value and a standard deviation, regardless of the test method for the estimation, it is recommended to carry out data migration based on this standard. If the estimated lifetime is unknown, the test interval sho
30、uld be three years or less. Considering the generational changeover of systems or applications, the user can determine a migration interval disregarding the estimated lifetime of the disks. Disks with shorter estimated lifetimes have more rapid degradation and require more frequent periodic tests. I
31、n addition, degradation of recorded data occurs by complex failure mechanisms. Storage lifetime, therefore, varies depending not only on temperature and humidity but also on many other effects such as exposure to light, corrosive gases, contamination, handling, and variation in playback subsystems.
32、Consequently, severe storage environments require more frequent periodic tests. The frequency of periodic testing also needs to be fixed based on the quality of the disks for storing data and the storage environment. 2 Normative references The following documents, in whole or in part, are normativel
33、y referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 16963, Information technology Digitally recorded media for
34、information interchange and storage Test method for the estimation of lifetime of optical media for long-term data storage ISO/IEC 12862, Information technology 120 mm (8,54 Gbytes per side) and 80 mm (2,66 Gbytes per side) DVD recordable disk for dual layer (DVD-R for DL) ISO/IEC 13170, Information
35、 technology 120 mm (8,54 Gbytes per side) and 80 mm (2,66 Gbytes per side) DVD re-recordable disk for dual layer (DVD-RW for DL) ISO/IEC 16448, Information technology 120 mm DVD Read-only disk ISO/IEC 17341, Information technology Data interchange on 120 mm and 80 mm optical disk using +RW format Ca
36、pacity: 4,7 Gbytes and 1,46 Gbytes per side (recording speed up to 4X) ISO/IEC 17342, Information technology 80 mm (1,46 Gbytes per side) and 120 mm (4,70 Gbytes per side) DVD re-recordable disk (DVD-RW) INTERNATIONAL ST ANDARD ISO/IEC 29121:2013(E) ISO/IEC 2013 All rights reserved 1 ISO/IEC 29121:2
37、013(E) ISO/IEC 17344, Information technology Data interchange on 120 mm and 80 mm optical disk using +R format Capacity: 4,7 Gbytes and 1,46 Gbytes per side (recording speed up to 16X) ISO/IEC 17592, Information technology 120 mm (4,7 Gbytes per side) and 80 mm (1,46 Gbytes per side) DVD rewritable
38、disk (DVD-RAM) ISO/IEC 23912, Information technology 80 mm (1,46 Gbytes per side) and 120 mm (4,70 Gbytes per side) DVD Recordable Disk (DVD-R) ISO/IEC 25434, Information technology Data interchange on 120 mm and 80 mm optical disk using +R DL format Capacity: 8,55 Gbytes and 2,66 Gbytes per side (r
39、ecording speed up to 16X) ISO/IEC 26925, Information technology Data interchange on 120 mm and 80 mm optical disk using +RW HS format Capacity: 4,7 Gbytes and 1,46 Gbytes per side (recording speed 8X) ISO/IEC 29642, Information technology Data interchange on 120 mm and 80 mm optical disk using +RW D
40、L format Capacity: 8,55 Gbytes and 2,66 Gbytes per side (recording speed 2,4X) 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply. 3.1 BER max maximum byte error rate at any consecutive 32 ECC blocks on a disk as measured in the first pass of the
41、decoder before correction Note 1 to entry: BER max is applied to DVD-RAM disks. 3.2 B migLife lifetime for use of data migration and same as B 0.0001Life which is 0,000 001 quantile of the lifetime distribution (i.e. 0,000 1 % failure time) or 99,999 9 % survival lifetime (see Annex E) 3.3 B 5Life 5
42、 percentile of the lifetime distribution (i.e. 5 % failure time) or 95 % survival lifetime 3.4 (B 5Life) L 95 % lower confidence bound of B 5Life 3.5 B 50Life 50 percentile of the lifetime distribution (i.e. 50 % failure time) or 50 % survival lifetime 3.6 data migration process to copy data from on
43、e storage device or medium to another 3.7 Error Correction Code ECC mathematical computation yielding check bytes used for the detection and correction of errors in data Note 1 to entry: For DVD-R, DVD-RW, DVD-RAM, +R, and +RW disks, the Reed-Solomon product code defined in ISO/IEC 16448:2002 for DV
44、D-ROM systems is applied. 3.8 error rate rate of errors on the recorded disk measured before error correction is applied2 ISO/IEC 2013 All rights reserved ISO/IEC 29121:2013(E) 3.9 initial performance test test of the recording performance of data recorded on a disk before storing 3.10 lifetime time
45、 that information is retrievable in a system 3.11 PI SUM 8 max maximum inner-parity (PI) error count at any consecutive 8 ECC blocks on a disk as measured in the first pass of the decoder before correction Note 1 to entry: See ISO/IEC 16448, ISO/IEC 23912, ISO/IEC 17341, ISO/IEC 17342, and ISO/IEC 1
46、7344. 3.12 periodic performance test periodic test of the recording performance of data recorded on a disk during the storage 3.13 retrievability ability to recover physical information as recorded 3.14 storage time time that a disk is being stored since data is recorded on the disk 3.15 substrate t
47、ransparent layer of the disk, provided for mechanical support of the recording or recorded layer, through which the optical beam accesses the recordable/recorded layer 3.16 system combination of hardware, software, storage medium, and documentation used to record, retrieve, and reproduce information
48、 3.17 uncorrectable error error in the playback data that could not be corrected by the error correcting decoders 3.18 X migLife migration interval (year) which is determined by user Note 1 to entry: See Annex F. 4 Test methods 4.1 Test parameters For DVD-R disk defined in ISO/IEC 23912 and ISO/IEC
49、12862, DVD-RW disk defined in ISO/IEC 17342 and ISO/IEC 13170, +R disk defined in ISO/IEC 17344 and ISO/IEC 25434, and +RW disk defined in ISO/IEC 17341, ISO/IEC 26925 and ISO/IEC 29642, the maximum inner-parity error shall be measured at any consecutive 8 ECC blocks (PI SUM 8 max) in the first pass of the decoder before correction. For a DVD-RAM disk defined in ISO/IEC 17592, the maximum Byte error rate (BER max) shall be measured (see Annex C). ISO/IEC 2013 All rights reserved 3 ISO/IEC 29121:2013(E) 4.
