STORAGE SYSTEM AND COMMUNICATION PATH CONTROL METHOD
In a storage system, when a communication path for remote copying from a primary volume to a secondary volume is set, a storage node in a primary site makes an inquiry to a discovery node in a secondary site about node information on a node having a secondary volume paired with a primary volume. Based on the node information acquired from the discovery node, a primary volume owner node sets a communication path between the primary volume owner node and a secondary volume owner node, the communication path being used for remote copying volume data from the primary volume to the secondary volume.
1 . A storage system comprising a primary site and a secondary site each of which includes a plurality of storage nodes and one or more drives, the storage nodes each having a processor package including a processor and a memory, wherein
storage nodes making up the primary site include a primary volume owner node having a primary volume,
storage nodes making up the secondary site include a secondary volume owner node having a secondary volume making a pair with the primary volume, and a discovery node that as a replay to an inquiry, sends node information on a node having a volume in own site,
when a communication path for remote copying from the primary volume to the secondary volume is set, a storage node in the primary site makes an inquiry to a discovery node in the secondary site about node information on a node having the secondary volume paired with the primary volume,
as a replay to the received inquiry, the discovery node sends the node information on the node having the secondary volume, and
based on the node information acquired from the discovery node, the primary volume owner node sets a communication path between the primary volume owner node and the secondary volume owner node, the communication path being used for remote copying volume data from the primary volume to the secondary volume.
2 . The storage system according to claim 1 , wherein
the primary volume owner node and the secondary volume owner node each include an active node that executes a process, and a standby node that takes over the process when a failure occurs at the active node,
a process of setting the communication path includes setting the communication path between the primary volume owner node as the active node and the secondary volume owner node as the active node and setting a retreatment path between the primary volume owner node as the active node and the secondary volume owner node as the standby node, and
when a failure occurs at either the primary volume owner node as the active node or the secondary volume owner node as the active node, the standby node takes over a process from the active node having developed the failure, and the communication path for the pair of volumes is switched to the retreatment path to continue processing between the pair of volumes.
3 . The storage system according to claim 1 , wherein
each of the primary site and the secondary site includes the discovery node,
in each of the primary site and the secondary site, a plurality of storage nodes include an active node that executes a process, and a standby node that takes over the process when a failure occurs at the active node, and wherein
when a failure occurs at either the primary volume owner node as the active node or the secondary volume owner node as the active node, the standby node takes over a process from the active node having developed the failure, the active node in a site in which the failure has not occurred makes an inquiry to the discovery node in a site in which the failure has occurred about node information on the node having taken over the process, and
based on the node information acquired from the discovery node, the primary volume owner node resets the communication path leading from the active node in the site in which the failure has not occurred to the node having taken over the process and continues processing between the pair of volumes.
4 . The storage system according to claim 1 , wherein when a given volume is transferred between storage nodes in one site of the primary site and the secondary site, an owner node of a volume in another site of the primary site and the secondary site, the volume making the pair with the given volume resets the communication path between the owner node and a transfer destination node of the given volume in the one site.
5 . The storage system according to claim 1 , wherein
when a given volume is transferred between storage nodes in one site of the primary site and the secondary site, a transfer source node of the given volume transferred sends a notification of a current communication path being not optimum, to an owner node of a volume in the other site of the primary site and the secondary site, the volume making the pair with the given volume transferred, and
the owner node of the volume in the other site, the owner node receiving the notification, makes an inquiry to a discovery node in the one site about node information on a transfer destination node having the given volume, and based on the node information acquired from the discovery node to which the inquiry has been made, resets the communication path between the owner node and the transfer destination node of the given volume.
6 . The storage system according to claim 1 , wherein
each of the primary site and the secondary site includes a shared database storing configuration information shared between storage nodes in each of the sites, and
when one site of the primary site and the secondary site makes an inquiry to any one of storage nodes in the other site of the primary site and the secondary site about a node having a volume in the other site, a storage node having received the inquiry acquires node information on the node about which the inquiry has been made, by referring to the shared database in the site the storage node belongs to, and sends a replay to the inquiry.
7 . The storage system according to claim 1 , wherein
the primary site includes a journal volume storing updating difference data of a plurality of primary volumes, together with metadata including writing time information,
at given timing, the secondary volume owner node transmits a journal read request to the primary volume owner node,
the primary volume owner node having received the journal read request transfers the updating difference data and metadata to the secondary volume owner node, referring to the journal volume in the primary site, and
the secondary volume owner node writes the updating difference data transferred from the primary volume owner node, to the corresponding secondary volume, referring to the metadata.
8 . A communication path control method carried out by a storage system including a primary site and a secondary site each of which includes a plurality of storage nodes and one or more drives, the storage nodes each having a processor package including a processor and a memory, wherein
storage nodes making up the primary site include a primary volume owner node having a primary volume,
storage nodes making up the secondary site include a secondary volume owner node having a secondary volume paired with the primary volume, and a discovery node that as a replay to an inquiry, sends node information on a node having a volume in the secondary site,
when a communication path for remote copying from the primary volume to the secondary volume is set, a storage node in the primary site makes an inquiry to a discovery node in the secondary site about node information on a node having the secondary volume paired with the primary volume,
as a replay to the received inquiry, the discovery node sends the information on the node having the secondary volume, and
based on the node information acquired from the discovery node, the primary volume owner node sets a communication path between the primary volume owner node and the secondary volume owner node, the communication path being used for remote copying volume data from the primary volume to the secondary volume.