Memory system, memory controller, and method of operating memory system for caching journal information for zone in the journal cache

A memory controller for a memory device, comprising:

• a memory interface in communication with the memory device;
• and
• a processor in communication with the memory device through the memory interface and configured to:
• control the memory device to store data into zones of memory blocks in the memory device by assigning each data to be written with an address subsequent to a most recently written address in a zone, wherein the zones of memory blocks are split from a namespace in the memory device;
• store, in a journal cache, journal information comprising mapping information between a logical address and a physical address for one of the one or more zones;
• search, in the journal cache, for journal information corresponding to a target zone targeted to write data, when mapping information for the target zone among the one or more zones is updated;
• and
• replace the journal information corresponding to the target zone with journal information comprising the updated mapping information,
• wherein, when a number of pieces of journal information, which can be additionally stored in the journal cache, is smaller than or equal to a first threshold, the processor evicts all pieces of journal information cached in the journal cache from the journal cache, and
• wherein the processor migrates all pieces of journal information evicted from the journal cache to a journal buffer, and when a number of pieces of journal information to be additionally stored in the journal buffer is smaller than or equal to a second threshold, writes all pieces of journal information stored in the journal buffer in the memory device.

A method of operating a memory system comprising a memory device, the method comprising:

• controlling the memory device to store data into zones of memory blocks in the memory device by assigning each data to be written with an address subsequent to a most recently written address in a zone, wherein the zones of memory blocks are split from a namespace in the memory device;
• storing, in a journal cache, journal information comprising mapping information between a logical address and a physical address for one of the one or more zones;
• searching, in the journal cache, for journal information corresponding to a target zone targeted to write data when mapping information for the target zone among the one or more zones is updated;
• replacing the journal information corresponding to the target zone with journal information comprising the updated mapping information,
• when a number of pieces of information to be additionally stored in the journal cache, is smaller than or equal to a first threshold, evicting pieces of journal information cached in the journal cache from the journal cache,
• migrating all pieces of journal information evicted from the journal cache to a journal buffer;
• and
• when a number of pieces of journal information to be additionally stored in the journal buffer, is smaller than or equal to a second threshold, writing all pieces of journal information stored in the journal buffer in the memory device.