Method for Improving Information Storage Reliability in Long-Term Electronic Storage on Optical Disks Arrayed in RAID-6 by Mixing Backup Copy Disks

The purpose of this study was to propose a method for ensuring high reliability of information storage in long-term electronic storage on optical disks arrayed in RAID-6 by mixing backup copy disks. We built a mathematical model of information storage reliability. The sample calculations for robotic library Panasonic LB-DH8 show that the method makes it possible to minimize the number of information backup copies ensuring the reliability targets specified when designing the information storage. The LB-DH8 library allows for combining in RAID-6 only the discs within one cartridge and we can obtain a spare copy of the cartridge on another cartridge. However, the exchange of individual disks between the cartridges in automatic mode is impossible. Therefore, for practical implementation of the method on the library LB-DH8 operator intervention is required to manually exchange the respective discs between the cartridges. We demonstrated the use of the model for calculating the maximum number of optical disks in RAID-6 to reduce the redundancy of the disks array.

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