Abstract: A storage apparatus has a tiered pool including a plurality of storage tiers formed by a plurality of real page groups having different input/output performance and provides a virtual volume to which a storage area is allocated by a real page unit. At a time point before new data to be written to the virtual volume occurs based on a data object, if a real page is allocated to a write destination virtual page which is a write destination of the new data, a host computer transmits a change command to change the real page allocated to the write destination virtual page to a real page in a storage tier having predetermined performance to the storage apparatus. The storage apparatus changes the real page allocated to the write destination virtual page to a real page in the storage tier having the predetermined performance according to the change command.

Abstract: A computer is coupled to a storage apparatus having a hierarchical pool with multiple storage tiers that are multiple page groups having different IO performance. Page data is migrated between storage tiers in accordance with a migration request. The computer has a storage device that stores performance requirement management information denoting a performance requirement of a task, which is an execution unit of a prescribed process, and IO performance information enabling identification of a difference in IO performance between the multiple storage tiers. A control device calculates an amount of change predicted in the task execution performance on supposition that one or more data objects for use in the task are to be migrated to a page in another storage tier, and identifies, based on the predicted amount of change, one or more data objects capable of being migrated to a page in another storage tier.

Abstract: A storage apparatus has a tiered pool including a plurality of storage tiers formed by a plurality of real page groups having different input/output performance and provides a virtual volume to which a storage area is allocated by a real page unit. At a time point before new data to be written to the virtual volume occurs based on a data object, if a real page is allocated to a write destination virtual page which is a write destination of the new data, a host computer transmits a change command to change the real page allocated to the write destination virtual page to a real page in a storage tier having predetermined performance to the storage apparatus. The storage apparatus changes the real page allocated to the write destination virtual page to a real page in the storage tier having the predetermined performance according to the change command.