MEXT Program Development of Highly Available Anti-disaster Information Storage Infra-structure

The total capacity of created information is rapidly growing due to the rapid expansion of cloud and big data applications.Information storage and magnetic recording devices, e.g., disk drives and tape drives, are indispensable in information storage technology. However, the last East-Japan Great Earthquake taught us that big disasters destroy important information through widespread and severe damage of data servers at storage sites. In order to avoid such social loss in future caused by forecast big disasters, we are developing anti-disaster storage technologies thanks to a grant from MEXT (Ministry of Education, Culture, Sports, Science, and Technology) from 2012 to 2016. Tohoku University, Hitachi Ltd., and Hitachi Solutions East Japan Ltd. have set up the development team.

Figure 1 Risk-aware data backup for Tsunami disaster in the case of two backups.

Figure 1 Risk-aware data backup for Tsunami disaster in the case of two backups.

Conventional storage systems are designed not to lose stored information through individual device failure, but in big disasters, entire storage systems in offices, buildings, and other sites can be totally lost. Another fatal system failure is the loss of internet connections due to long term network damage, sometimes lasting for several weeks. This means that conventional disaster recovery technology is useless. Taking these lessons into account, in our newly developed storage technology each storage server makes a data backup in the vicinity, within a radius of dozens of kilometers. The nearby backups can be accessible even when internet connections are lost. But the risk of losing the entire data because of the short distance between backups should be considered. To avoid the risk of information loss a “risk-aware copy algorithm” is introduced. Fig. 1 shows the basic configuration of the system. Each storage site has a risk index to determine the backup site according to the minimum total risk. The target is that the 90% of the information can be available when half of the storage devices are damaged.

Figure 2 Testing system using medication notebook applications

Figure 2 Testing system using medication notebook applications

In order to verify the availability of the storage system after a supposed disaster, testing using a newly developed electronic medication notebook application was carried out. At the last Great Earthquake we learned the importance of medication notebooks for maintaining clients’ health. The testing diagram is shown in Fig. 2. The service program is developed as an application for Android smartphones. A client receives medication information at a pharmacy, which is then sent to the new storage system through the Internet. We have shown that 90 % of the clients can get their information at a hospital after a disaster by using the risk-aware backup for 100 thousand clients. We are now improving the program for the case of one million clients, assuming the population of Sendai-city.

This program also incorporates high-speed disk drive technology, anti-disaster smart networks, and applications of the SML# programing framework.

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