Storage system and its logical unit management method

摘要

The size of management information pages for storing format management information is minimized and a management size of the management information pages is reduced.;A storage system has a controller(s) for managing an area of a management-information logical unit, which stores format management information to manage whether an access-target logical unit has been formatted or not, by using a former page area and a latter page area, wherein when formatting the access-target logical unit, the controller: calculates a capacity of the format management information based on a capacity of the access-target logical unit; calculates the number of management information pages according to a ratio of the calculated capacity of the format management information to a page management unit; allocates the format management information of one page to the former page area and manages its storage location by using a former page area address; and allocates the format management information of two or more pages to the latter page areas and manages their storage locations by using latter page area addresses and a page length.

主权项

1. A storage system comprising:
a plurality of storage devices configuring a RAID group; a plurality of access-target logical units, each of which is a logical unit formed in a storage area of the plurality of storage devices and is an access target of an access requestor; a management-information logical unit that is a logical unit formed in the storage area of the plurality of storage devices and whose area for storing format management information for managing whether each of the access-target logical units has been formatted or not is divided into a former page area and a latter page area; and one or more controllers for controlling data input to, or output from, each logical unit and executing format processing on the access-target logical units; wherein when executing the format processing on the access-target logical units, the controller: calculates a capacity of the format management information based on a capacity of each of the access-target logical units; calculates, according to a ratio of the calculated capacity of the format management information to a page management unit with a specified capacity, the number of management information pages necessary to manage the format management information using the page management unit; allocates part of the format management information for the plurality of access-target logical units, from among the format management information corresponding to the calculated number of the management information pages, to the former page area; allocates the remaining format management information for the plurality of access-target logical units, from among the format management information corresponding to the calculated number of the management information pages, to the latter page area by considering allocation of the plurality of access-target logical units in the RAID group; and stores an execution result of the format processing as the format management information in the former page area or the latter page area.