ISO/IEC 29121:2009

INTERNATIONAL ISO/IEC
STANDARD 29121
First edition
2009-02-15

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 l'information — Supports enregistrés numériquement
pour échange et stockage d'information — Méthode de migration de
données pour disques DVD-R, DVD-RW, DVD-RAM, +R, et +RW




Reference number
ISO/IEC 29121:2009(E)
©
ISO/IEC 2009

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ISO/IEC 29121:2009(E)
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ISO/IEC 29121:2009(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Test methods.3
4.1 Test parameters .3
4.2 Test Drive.3
4.2.1 Test drive calibration.3
4.2.2 Test preparation.4
4.2.3 Test execution.4
4.3 Test area .4
5 Test result evaluation.4
5.1 Initial performance test result evaluation .4
5.2 Periodical performance test result evaluation.5
6 Test frequency .6
7 Prevention of deterioration.6
Annex A (informative) Causes of deterioration for DVD-R, DVD-RW, DVD-RAM, +R, and +RW
disks.7
A.1 Deterioration.7
A.2 Disk structure.7
A.3 Causes of deterioration.7
A.4 Nature of deterioration .8
A.5 Effects of deterioration .8
Annex B (informative) Recommendations on handling, storage and cleaning conditions for DVD-
R, DVD-RW, DVD-RAM, +R, and +RW disks.9
B.1 Handling.9
B.2 Storage.9
B.3 Cleaning.10
Annex C (informative) Relation between BER and PIE SUM 8 .11
Annex D (informative) Normalization of the time scales.12
Annex E (informative) Test area.14
Bibliography .15

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ISO/IEC 29121:2009(E)
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 subject 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 (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 committees 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 be held responsible for identifying any or all such patent rights.
ISO/IEC 29121 was prepared by Joint Technical Committee ISO/IEC JTC 1, Infomation technology,
Subcommittee SC 23, Digitally Recorded Media for Information Interchange and Storage.

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ISO/IEC 29121:2009(E)
Introduction
Many organizations now use optical 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 ISO
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 must be regularly
verified to assure that information on existing recorded disks will continue to be recoverable. Users may have
a maintenance policy that protects disks against unanticipated failure or use, such as by making one archival
copy, another to function as a backup or master, and another for routine access. Hardware support life cycles
typically vary between 5 to 10 years and technology lifecycles usually end after 20 years. Consequently,
recordings that require a longer lifecycle may have to be transferred to upgraded platforms every 10 to
20 years.
Optical disks for long-term storage should be evaluated. Significant longevity differences may exist for disks
from different manufacturers and also between disks from the same manufacturer. It is preferable that the
disks for long-term preservation should have a long life expectancy, which can be estimated according to
ISO/IEC 10995.
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 initial recorded quality that maintains this condition for life is expected to have superior longevity.
Because errors in read data are corrected at error correction decoder, it is impossible to detect degradation
without detecting raw error rate or raw error number. The raw error can be detected with standard test drive.
Quality of the disk can be specified by the number of erroneous inner parity with DVD-R, DVD-RW, +R, and
+RW disks. That of DVD-RAM disk is defined by byte error rate. Deterioration can be monitored by checking
the raw error numbers and must continue to be monitored. Methods described in this standard define a quality
control policy that can non-destructively identify degradation, 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; i.e. the use of red Laser Diode, the use of two 0,6 mm thick substrates bonded together by an
adhesive layer to protect the disks from dust combined with Write Once recording layers (DVD-R, +R) or
Phase Change recording layers (DVD-RW, DVD-RAM, +RW), the use of a 0,60 or 0,65 NA objective lens to
ensure good spatial margins required for a professional data archive solution, and the use of dual recording
layers with a spacer between them in addition to conventional single recording layer.
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INTERNATIONAL STANDARD ISO/IEC 29121:2009(E)

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 provides specifications of the data migration method for archival data storage
which allow manufacturers storage systems that use DVD-R (ISO/IEC 23912:2005), DVD-RW
(ISO/IEC 17342:2004), DVD-RAM (ISO/IEC 17592:2004), +R (ISO/IEC 17344:2006 and
ISO/IEC 25434:2007), and +RW (ISO/IEC 17341:2006 and ISO/IEC 26925:2006) disks for information
storage to classify disk longevity potential on the basis of initial performance requirements and to allow users
to monitor continuing conformance with the error limits required for its class identified by the manufacturer of
the drive/disk. Digital data can be migrated to a next new disk without loss from the present disk as far as the
data errors are completely corrected before and during the migration and the copy of the data is allowed.
The methodology for data migration does not apply to disks with short archival storage time but to disks with
long archival storage time. Disks with shorter archival storage time have more rapid degradation and require
more frequent periodical tests. In addition, degradation of recorded data has a complex failure mechanism.
Archival storage time, therefore, varies depending not only on temperature and humidity but also on many
other effects, such as exposure to light, corrosive gases, contaminations, handling, and variation in playback
subsystems. Consequently, severer storage environment requires more frequent periodical tests. Frequency
of periodical tests is based on the quality of the disks for storing data and the storage environment.
2 Normative references
The following referenced documents 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/IEC 10995:2008 Information technology — Digitally recorded media for information interchange and
storage — Test method for the estimation of the archival lifetime of optical
media
ISO/IEC 16448:2002 Information technology — 120 mm DVD — Read-only disk
ISO/IEC 17592 Information technology — 120 mm (4,7 Gbytes per side) and 80 mm
(1,46 Gbytes per side) DVD rewritable disk (DVD-RAM)
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ISO/IEC 29121:2009(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
archival
having ability of a medium or system to maintain the retrievability of recorded information for a specified
extended period of years
3.2
BER max
maximum byte error rate at any consecutive 32 ECC blocks on a disk as measured in the first pass of the
decoder before correction
3.3
data migration
process to copy data from one storage device or medium to another
3.4
error correction code
ECC
mathematical computation yielding check bytes used for the detection and correction of errors in data
NOTE For DVD-R, DVD-RW, DVD-RAM, +R, and +RW disks, the Reed-Solomon product code defined in
ISO/IEC 16448:2002 for DVD-ROM systems is applied.
3.5
error rate
rate of errors on the recorded disk measured before error correction is applied
3.6
initial performance test
test of the recording performance of data recorded on a disk before storing
3.7
life expectancy
estimated lifetime
3.8
lifetime
time that information is retrievable in a system
3.9
PIE SUM 8 max
maximum inner parity error at any consecutive 8 ECC blocks on a disk as measured in the first pass of the
decoder before correction
NOTE See ISO/IEC 16448:2002, ISO/IEC 23912:2005, ISO/IEC 17341:2005, ISO/IEC 17342:2004 and
ISO/IEC 17344:2006.
3.10
periodical performance test
periodical test of the recording performance of data recorded on a disk during the storage
3.11
retrievability
ability to recover physical information as recorded
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ISO/IEC 29121:2009(E)
3.12
stress
temperature and relative humidity variables to which the recorded disk is exposed for the duration of test
intervals
3.13
storage time
time that a disk is being stored since data is recorded on the disk
3.14
substrate
transparent layer of the disk, provided for mechanical support of the recording or recorded layer, through
which the optical beam accesses the recordable / recorded layer
3.15
system
combination of hardware, software, storage medium and documentation used to record, retrieve and
reproduce information
3.16
uncorrectable error
error in the playback data that could not be corrected by the error correcting decoders
4 Test methods
4.1 Test parameters
For DVD-R, DVD-RW, +R, and +RW disks, the maximum inner parity error shall be measured at any
consecutive 8 ECC blocks (PIE SUM 8 max) in the first pass of the decoder before correction.
For a DVD-RAM disk, the maximum Byte error rate (BER max) shall be measured (see Annex C).
The objective of this test method is to establish a practical estimation of the retrievability of the recorded data
on a disk without producing uncorrectable errors, in response to time at controlled stress conditions to
produce accelerated aging.
In this case, measuring the PIE SUM 8 max or the BER max is principal method to estimate actual
retrievability of a disk instead of measuring other parameters to confirm the disk quality specified in each
specifications.
4.2 Test Drive
Test drive shall comply with ISO/IEC 16448 for DVD-R, DVD-RW, +R, and +R disks and ISO/IEC 17592 for
DVD-RAM disk or shall be equivalent. It shall have capability to measure the PIE SUM 8 max for DVD-R,
DVD-RW, +R, and +RW disks and the BER max for a DVD-RAM disk, respectively.
4.2.1 Test drive calibration
The test drive shall be calibrated by using a calibration disk prepared by the test drive manufacturer based on
the calibration procedure defined by the manufacturer. The calibration shall be done at the intervals
recommended by the manufacturer.
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ISO/IEC 29121:2009(E)
4.2.2 Test preparation
Prior to conducting tests, the disks shall be visually examined to determine whether it contains dust, finger
prints, or other contaminants. If appropriate, such contaminants shall be removed in accordance with the disk
manufacturer’s recommendations. Certain options are contained in Annex A. Microscopic examination may
reveal physical deterioration, such as delamination and porosity of the protective coating.
4.2.3 Test execution
Before testing disks, the test drive shall be verified by checking the calibration disk supplied with the test drive
or publicly verified. If the drive passes the calibration check, the disk to be checked shall be tested by the test
drive.
Test results shall be judged by the PIE SUM 8 max for DVD-R, DVD-RW, +R, and +RW disks or the BER max
for a DVD-RAM disk.
4.3 Test area
The entire recorded area of all the disks should be tested in order
...