Compound storage system and storage control method to configure change associated with an owner right to set the configuration change
One or more storage systems are connected to one or more storage boxes comprising multiple storage devices. Multiple storage areas provided by one or more storage boxes include an allocated area, which is a storage area that is allocated to a virtual volume, and an empty area, which is a storage area that is not allocated to any logical volume. Multiple owner rights corresponding to multiple storage areas are set in one or more storage systems. A storage system having an empty area owner right changes an empty area to the allocated area by allocating the empty area. In a case where a configuration change (a relative change in the number of storage boxes with respect to the number of storage systems) is performed, a first storage system that exists after the configuration change sets, in the first storage system, either more or fewer owner rights than the owner rights, which have been allocated to the first storage system before the configuration change.
1. A compound storage system, comprising:
multiple storage devices;
multiple storage systems configured to perform processing related to data I/O (input/output) to/from the multiple storage devices, and
a controller configured to:
determine that a first storage system of the multiple storage systems possesses an allocation right for a storage area of one of the multiple storage devices, and
responsive to occurrence of a predetermined condition, determine that the allocation right is to be moved between the first storage system and a second storage system of the multiple storage systems.
2. The compound storage system according to claim 1 , wherein the first storage system comprises a control right to perform I/O on the storage area of the storage device, and
the first storage system is configured to determine that the control right is to be moved between the first storage system and the second storage system under a predetermined condition to move the control right.
3. The compound storage system according to claim 2 , wherein the control right comprises a right to perform I/O on the storage area of the storage device via a logical volume, and
the allocation right comprises a right to allocate the storage area of the storage device to the logical volume.
4. The compound storage system according to claim 2 , wherein the controller is configured to move a control right comprising a right to perform I/O on a first storage area and an allocation right for a second storage area associated with the first storage area to a same storage system.
5. The compound storage system according to claim 1 , wherein the controller is configured to perform a migration of the allocation right for the storage area in accordance with a change in a number of storage systems or in a number of storage devices.
6. The compound storage system according to claim 5 , wherein the predetermined condition includes adding a third storage system to the compound storage system, and the controller is configured to move the allocation right to the third storage system.
7. The compound storage system according to claim 5 , wherein the predetermined condition includes ejecting the second storage system from the compound storage system, the controller is configured to move the allocation right from the second storage system to another storage system of the multiple storage systems.
8. The compound storage system according to claim 1 , wherein the controller is configured to perform a migration of the allocation right for the storage area in accordance with a balance of load on the multiple storage systems.
9. The compound storage system according to claim 5 , wherein a migration-destination storage system is configured to receive a notification comprising a number of segments related to the allocation right from a migration-source storage system along with the migration of the allocation right.
10. The compound storage system according to claim 5 , wherein a migration-destination storage system is configured to receive a notification comprising address information of a real page related to the allocation right from a migration-source storage system along with the migration of the allocation right.
11. A method for moving an allocation right within a compound storage system including multiple storage devices, multiple storage systems, and a controller, the method comprising:
performing, by one or more of the multiple storage systems, processing related to a data I/O (input/output) to/from the multiple storage devices,
determining, by the controller, that a first storage system of the multiple storage systems possesses an allocation right for a storage area of one of the multiple storage devices, and
responsive to occurrence of a predetermined condition, determining, by the controller, that the allocation right is to be moved between the first storage system to a second storage system of the multiple storage systems.