ISO IEC 29121 pdf – Information technology — Digitally recorded media for information interchange and storage — Data migration method for optical disks for long-term data storage

ISO IEC 29121 pdf – Information technology — Digitally recorded media for information interchange and storage — Data migration method for optical disks for long-term data storage
The test area is the recorded area to be tested in a disk.
The whole recorded area of all disks shall be tested for the initial performance test.
The whole recorded area of all disks should be tested for the periodic performance test. Although theintegrity of the data becomes lower, the user may reduce the test area and/or the number of sample disksbased on a certain sampling method, considering the value of information (see Annex G-for additionalinformation).For the reduction of test area, see ISO/IEC 16963:2017,7.5, for additional information.The number of sample disks should be enough to guarantee statistical effectiveness. If the sample diskshave different attributes such as disk standards, recording conditions or storage conditions, the disksshould be divided into groups of disks considering the attributes so that the sampling can be applied oneach group with the statistical effectiveness.
5.4Test drive
5.4.1 General
For DVD-R and DVD-RW disks，+R and +RW disks, the test drive shall have capability to measurePIsum 8,max.
For DVD-RAM disk, the test drive shall have capability to measure BERmax.
For CD-R and CD-RW disks, the test drive shall have capability to measure C1ave 10,max.
For BD recordable disks and BD rewritable disks, the test drive shall have capability to measureRSERmax.
The test drive shall have the capability to evaluate the error rate levelspecified in the initial performancetest and the periodic performance test.
There are two cases of the test drive.One is that the drive serves both as a test drive and a recorderwhich records the data on the disk.The other is that the test drive is different from the recorder.Forboth cases, the data recorded on the disk by the recorder shall fulfil the error rate level specified in theinitial performance test and the periodic performance test.
NOTE The measuring circuit for RSER described in ISO/IEC 30191 and ISO/IEC 30193 is different fromthat described in IsSo/IEC 30190 and ISo/IEC 30192,especially in HF signal pre-processing circuit. SeeISO/IEC30190:2021,Annex H, and ISO/IEC 30191:2021,Annex H, for additional information.
5.4.2Test drive check
The test drive shall be checked by using a reference disk prepared by the test drive manufacturer orthe disk prepared by the user, so that it fulfils the requirements in 5.4.1. When using the referencedisk prepared by the test drive manufacturer, the check of the test drive shall be done at the intervalsrecommended by the manufacturer. When using the disk prepared by the user, it is recommended forthe user to set an appropriate interval and to check the test drive at the interval.
5.5 Disk preparation
Prior to conducting tests, the disks shall be checked that there is no dust, fingerprints or othercontaminants on them. If there is dust, fingerprints or other contaminants, such contaminants shall beremoved in accordance with the procedure recommended by the disk-manufacturer.Certain options arecontained in Annex B.Microscopic examination can reveal physical deterioration, such as delaminationand porosity of the protective coating.
5.6 Test execution Before testing disks, the test drive shall be verified by the procedure defined in 5.4.2 . If the drive does not pass the verification, the test drive shall not be used for the test. On testing disks, care handling of the disks shall be taken in order to avoid introducing unexpected defects (see Annex I for additional information).
6 Test interval for periodic performance test In order to determine the test interval for the periodic performance test, B mig life is used. B mig life shall be calculated according to Annex E , and B 50 life and B 5 life or B 50 life and standard deviation, σ, shall be provided (see Clause 4). The test interval shall be determined according to Annex F. In case B mig life is not available as shown below, the test interval should be three years or less. Relaxation of the test interval causes the risk of data loss and failure in the data migration. In case such a risk is unacceptable, the test interval of three years or less is strongly recommended.