Storage system and control method for data-type redundancy and non-volatile data management

A storage control method to be executed by each of a plurality of nodes constituting a storage system, the method comprising:

• when there is data to be stored into a segment allocated from a cache,
• the node performing redundancy-and-non-volatilization determination that is determination for the segment as to whether redundancy which is to transfer redundant data of the data in the segment to another node is required, and whether non-volatilization which is to store the data in the segment into a non-volatile area is required according to a type of the data, and
• the node controlling, based on the determination, whether to perform the redundancy of the data in the segment and whether to perform the non-volatilization of the data in the segment, wherein
• the plurality of nodes are a plurality of secondary nodes constituting a secondary storage system,
• among the plurality of secondary nodes, a first secondary node has
• a secondary journal volume which is a volume in which a journal is stored, the journal including data to be written into a primary volume in a primary storage system and metadata including a sequence number indicating an order in which the data is to be written,
• a secondary volume that forms a pair with the primary volume in the primary storage system,
• a first secondary cache that is a cache in the secondary node, and
• a first secondary processor that is a processor in the secondary node,
• the first secondary processor is configured to:
• allocate, from the first secondary cache, the segment in which the journal is to be stored,
• when the data to be stored in the allocated segment is the journal, determine for the segment that the redundancy is not required, and
• when it is determined for the segment that the redundancy is not required, not perform the redundancy which is to write the journal in the segment to the secondary journal volume and transfer the redundant data of the journal in the segment to a second secondary node having a secondary mirror volume that is a mirror volume of the secondary volume, and
• for each of the plurality of secondary nodes, the volume is an area based on one or more non-volatile media inside or outside the secondary node.

A storage system comprising:

• a plurality of nodes each including a memory in which a cache is provided and a processor connected to the memory, wherein
• in each of the plurality of nodes, when there is data to be stored in a segment allocated from the cache, the processor is configured to:
• determine, for the segment, whether redundancy which is to transfer redundant data of the data in the segment to another node is required, and whether non-volatilization which is to store the data in the segment into a non-volatile area is required according to a type of the data, and
• control, based on the determination, whether to perform the redundancy of the data in the segment and whether to perform the non-volatilization of the data in the segment, and
• for each of the plurality of nodes, the non-volatile area is an area based on one or more non-volatile media inside or outside the node,
• the plurality of nodes are a plurality of secondary nodes constituting a secondary storage system,
• among the plurality of secondary nodes, a first secondary node has
• a secondary journal volume which is a volume in which a journal is stored, the journal including data to be written into a primary volume in a primary storage system and metadata including a sequence number indicating an order in which the data is to be written,
• a secondary volume that forms a pair with the primary volume in the primary storage system,
• a first secondary cache that is a cache in the secondary node, and
• a first secondary processor that is a processor in the secondary node,
• the first secondary processor is configured to:
• allocate, from the first secondary cache, the segment in which the journal is to be stored,
• when the data to be stored in the allocated segment is the journal, determine for the segment that the non-volatilization is not required, and
• when it is determined for the segment that the non-volatilization is not required, not perform the non-volatilization which is to store the journal in the segment into the non-volatile area, and
• for each of the plurality of secondary nodes, the volume is an area based on one or more non-volatile media inside or outside the secondary node.

A storage control method to be executed by each of a plurality of nodes constituting a storage system, the method comprising:

• when there is data to be stored into a segment allocated from a cache,
• the node performing redundancy-and-non-volatilization determination that is determination for the segment as to whether redundancy which is to transfer redundant data of the data in the segment to another node is required, and whether non-volatilization which is to store the data in the segment into a non-volatile area is required according to a type of the data, and
• the node controlling, based on the determination, whether to perform the redundancy of the data in the segment and whether to perform the non-volatilization of the data in the segment, wherein
• the plurality of nodes are a plurality of secondary nodes constituting a secondary storage system,
• among the plurality of secondary nodes, a first secondary node has
• a secondary journal volume which is a volume in which a journal is stored, the journal including data to be written into a primary volume in a primary storage system and metadata including a sequence number indicating an order in which the data is to be written,
• a secondary volume that forms a pair with the primary volume in the primary storage system,
• a first secondary cache that is a cache in the secondary node, and
• a first secondary processor that is a processor in the secondary node,
• the first secondary processor is configured to:
• allocate, from the first secondary cache, the segment in which the journal is to be stored,
• when the data to be stored in the allocated segment is the journal, determine for the segment that the non-volatilization is not required, and
• when it is determined for the segment that the non-volatilization is not required, not perform the non-volatilization which is to store the journal in the segment into the non-volatile area, and
• for each of the plurality of secondary nodes, the volume is an area based on one or more non-volatile media inside or outside the secondary node.