In recent years, memory systems comprising nonvolatile memories have been widely prevalent. As such a memory system, a solid state drive (SSD) based on a NAND flash technology is known.
SSD is also used as the storage in a server of the data center.
The storage used in a host computing system such as a server is required to exert high-level I/O performance.
For this reason, a new interface between a host and a storage has been recently proposed.
However, if the number of defective blocks included in the nonvolatile memory is increased, increase in the amount of replacement information to replace the defective blocks with the other blocks and increase in the read latency time due to a processing for this replacement may occur.
Accordingly, implement of a new technology of reducing an influence which results from increase in the defective blocks has been required.