Volume capacity virtualization is a technology for virtually allocating storage capacity regardless of actual capacity when storage capacity available on each server is being allocated. Actual storage capacity is arbitrarily allocated according to the timing at which each server actually uses storage regions once the servers start to operate. This technology makes it unnecessary to estimate allocated capacity in detail beforehand while the performance and availability prospects of each server are being considered, so the work load on a storage manager can be lightened. What's more, volume capacity virtualization enables operation under which the minimum required capacity is provided at operation start-up and capacity is added arbitrarily when a shortage looks likely; consequently, implementation and operational costs can be lowered.
