Optical disks have been used widely and offer the advantage for long-term digital data preservation usage. However, single-optical-disk based system has weaknesses for the data capacity and transfer rate compared to other devices.
To meet the emerging demands for the long-term preservation of digital data, the ECMA-405 standard solves the issues by introducing multiple-disc based system. The system deals multiple disks as a set and writes/reads the set of disks in parallel.
Developing an industry standard is needed for promoting the optical disk in the enterprise usage.
Thie standard specifies two types of optical disk formats: a non-parity disk type, which allows for read/write operations on all user data divided among 5 disks and; a parity disk type, which allows for read/write operations on all user data divided among 4 disks and for read/write operations on parity data from/to 1 disk.
Recording of data in all 5 available optical discs (Blu-ray and BDXL) is done using the UDF 1.5.file system and the packet writing method, which requires pre-formatting of the discs.
A multiple-disc storage system consists of system control firmware, Drive1, Drive2, Drive3, Drive4, and Drive5. A proprietary device driver enables the host to recognize five drives as a single drive and controls the five drives to record/read the data.
The system has been also designed to be able to read stored data even if the data recording fails in case of an unexpected electric power source down. The proprietary device driver will be able to read the logical block VAT address recorded before the data recording fails and the VAT information. Therefore the system will be able reproduce the data recorded before the data recording fails.