Patent ID: 8037239
Filing Date: 2011-10-11
Classification: G06F

Abstract:
1. A storage system adapted to be coupled to a plurality of host computers, comprising: a plurality of drives; and a controller managing a plurality of allocation on use (AOU) volumes to be provided to said plurality of host computers as superficial storage capacities, a plurality of storage areas provided from the plurality of drives, and a plurality of storage area groups including a first storage area group having a first attribute and including a plurality of first storage areas of said plurality of storage areas to be allocated to a first AOU volume of said plurality of AOU volumes, a second storage area group having a second attribute and including a plurality of second storage areas of said plurality of storage areas to be allocated to a second AOU volume of said plurality of AOU volumes, and a third storage area group including a plurality of third storage areas of said plurality of storage areas that are not included in either said first storage area group or said second storage area group, wherein said plurality of first storage areas of said first storage area group are provided from a plurality of first type drives among said plurality of drives, said plurality of second storage areas of said second storage area group are provided from a plurality of second type drives among said plurality of drives and said plurality of third storage areas of said third storage area group are plural kinds of storage areas provided from said plurality of first type drives and said plurality of second type drives among said plurality of drives, wherein an attribute of said plurality of first storage areas corresponds to at least a drive type of said plurality of first type drives and complies with said first attribute of said first storage area group, and an attribute of said plurality of second storage areas corresponds to at least a drive type of said plurality of second type drives and complies with said second attribute of said second storage area group, wherein said first attribute corresponds to at least a performance or reliability that is different from that of said second attribute, wherein after providing said first AOU volume, at least a part of said first AOU volume is allocated at least a part of said first storage areas to be able to store data received from at least one of said host computers, and wherein after providing said second AOU volume, at least a part of said second AOU volume is allocated at least a part of said second storage areas to be able to store data received from at least one of said host computers; wherein said controller is adapted to: if an unused storage capacity of said first storage area group is below a first threshold value, add, to said first storage area group, a fourth storage area which is provided from said third storage area group, wherein an attribute of said fourth storage area corresponds to at least said drive type of said plurality of first type drives and complies with said first attribute of said first storage area group; and if an unused storage capacity of said second storage area group is below a second threshold value, add, to said second storage area group, a fifth storage area which is provided from said third storage area group, wherein an attribute of said fifth storage area corresponds to at least said drive type of said plurality of second type drives and complies with said second attribute of said second storage area group.