Implementing snapshot and other functionality in KVSSD through garbage collection and FTL

An apparatus comprising a storage device, the storage device comprising:

• a flash translation layer (FTL) circuit configured to:
• cause user data to be stored in key-value pairs, and
• associate, upon request, a set of key-value pairs with a snapshot;
• a storage memory configured to:
• store key-value data pairs, and
• store a snapshot data structure that identifies, for at least one key-value pair, a snapshot the key-value pair is associated;
• and
• a snapshot counter configured to store an operation number associated with a snapshot, wherein the operation number is a number assigned to a memory operation that results in the storage of a key-value pair.

A system comprising:

• a processor configured to:
• write and read user data in key-value pairs, and
• manipulate snapshots of sets of the key-value pairs;
• and
• a memory storage device comprising:
• a flash translation layer (FTL) circuit configured to:
• cause data to be stored in key-value pairs, and
• associate, upon request, a set of key-value pairs with a snapshot;
• and
• a storage memory configured to:
• store a plurality of key-value data pairs, and
• store a snapshot data structure that identifies which snapshot a key-value pair is associated with;
• and
• wherein, in response to the processor requesting the creation of a snapshot:
• the flash translation layer (FTL) circuit stores a most recent operation number in a snapshot counter, wherein the operation number is a number assigned to a memory operation;
• and
• the snapshot data structure sets a bitmap for a most recent key-value pair associated with a key in the set of key-value pairs, and wherein the bitmap indicates that the key-value pair may be garbage collected.