Memory system having multiple channels and method of generating read commands for compaction in memory system

Abstract

According to one embodiment, a valid-cluster search module searches valid clusters included in first blocks, in each of channels, for compaction. A read command generator generates read commands used to read, in parallel, valid clusters to be migrated to a second block. The valid clusters searched in each of the channels comprise the valid clusters to be migrated. The valid clusters to be migrated correspond to a number of clusters simultaneously written to the second block and to a second number of channels in a first number of channels. A determination module determines the second number of channels corresponding to read commands to be generated next based on a situation of issuance of the read commands.