Patent ID: 7509454
Filing Date: 2009-03-24
Classification: G06F

Abstract:
1. A method for managing disk space in a first storage system, said first storage system being couple with a second storage system, the second storage system presenting at least one second storage volume configured with a plurality of physical storages in the second storage system as a storage resource to the first storage system, the first storage system presenting at least one virtual volume as a storage resource to a host device, the method for managing disk space in the first storage system comprising: managing a plurality of segments, including a first segment from at least one first storage volume configured with a plurality of physical storages in the first storage system and a second segment from the at least one second storage volume configured with a plurality of physical storages in the second storage system as free segments in a free segment pool; mapping the first and second segments from the free segment pool to the at least one virtual volume so as to present the first and second segments via the virtual volume to the host device; determining whether a number of the free segments in the free segment pool is below a predetermined threshold; and adding another segment from one of the at least one first storage volume of the first storage system or the at least one second storage volume of the second storage system to the free segment pool when the number of the free segments in the free segment pool is below the predetermined threshold.