US 8,943,270 B2 · Storage system, storage control method and storage control program

Abstract

In tiered storage subsystems in which pages are automatically allocated to appropriate storage media based on the access frequency in page units, since the number of storage media is not simply proportional to the performance, it was difficult to design in advance a tier configuration satisfying the required performance. According to the present invention, a cumulative curve of I/O distribution is created based on a result of measurement of I/O accesses performed to the storage subsystem, and RAID groups (RG) are allocated sequentially in order from RGs belonging to tiers having higher performances to the cumulative curve of I/O distribution. When either a performance limitation value or a capacity of the RG exceeds the cumulative curve of I/O distribution, a subsequent RG is allocated, and the process is repeated so as to compute the optimum tier configuration.

A storage system comprising:

a management device;
and
a storage subsystem coupled to one or more host computers;
wherein
the storage subsystem is composed of
multiple types of physical storage device groups storing data transmitted from the host computers;
and
a storage control unit for controlling the storage devices;
wherein the storage control unit is composed of
a storage unit;
and
a controller coupled to the multiple types of physical storage device groups, the storage unit and the host computer;
the physical storage device group being composed of one or more physical storage devices;
the multiple types of physical storage device groups being a base of multiple types of real page groups;
the types of real page groups being based on attributes of the physical storage device groups being the base of the real page groups;
the real page groups having multiple real pages;
the controller providing one or more virtual volumes to the one or more hosts;
the virtual volume being a virtual logical volume composed of multiple virtual pages;
the virtual page being a virtual storage area;
the real page being a substantive storage area;
the storage unit being caused to store an allocation information indicating the allocation relationship of real pages to virtual pages;
a configuration information indicating a configuration of the storage subsystem;
and
a monitored information which is information indicating an I/O type and an I/O frequency for each I/O type of each virtual page of the virtual volume;
and wherein
the controller is caused to update the I/O frequency of a certain virtual page in the monitored information according to the I/O of the certain virtual page or of a real page allocated to the certain virtual page;
and
the management device is caused to create a cumulative curve of I/O distribution of the I/O frequency and the capacity of the virtual page based on the monitored information;
compare a storage area in given units of the physical storage device groups to the created cumulative curve of I/O distribution;
and
compute the configuration of the physical storage device groups that satisfies a given performance requirement in the I/O distribution based on the compared result;
and
wherein the management device is caused to perform the following processes so as to create the cumulative curve of I/O distribution:
(1) rearrange virtual pages in order from the virtual pages having greater I/O frequency to the virtual pages having smaller I/O frequency;
(2) assemble the rearranged virtual pages in units of a given number of pages;
(3) calculate a percentage of each virtual page with respect to a total I/O frequency and computing a percentage of cumulative I/O frequency;
(4) calculate a percentage of each virtual page with respect to a total storage capacity of the virtual pages and compute a percentage of cumulative storage capacity;
(5) multiply the total number of I/O frequency by the percentage of cumulative I/O frequency so as to compute the cumulative I/O frequency;
and
(6) multiply the total storage capacity by the percentage of cumulative storage capacity so as to compute the cumulative storage capacity.

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Storage system, storage control method and storage control program

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Storage system, storage control method and storage control program

Life of this patent

Abstract

Claims12