Patent ID: 8447947
Filing Date: 2013-05-21
Classification: G06F

Abstract:
1. An information system comprising: a plurality of host computers; and a storage apparatus coupled with the host computers, the storage apparatus comprising a processor; a memory; and a storage controller which is configured to receive a declare chunk size command with a pool identifier for a pool among a plurality of pools, the declare chunk size command from the pool specifying a desired chunk size at the pool; receive an allocate chunk command with a pool identifier for allocating a chunk to a logical volume; and provide chunks of different chunk sizes to different pools with different pool identifiers, according to the desired chunk sizes of different declare chunk size commands and in response to different allocate chunk commands; wherein the chunk size is defined when the storage controller receives the declare chunk size command; wherein the storage controller provides a chunk of the defined chunk size to the pool with the pool identifier when the storage controller receives the allocate chunk command; wherein the pool preserves a plurality of chunks having the defined chunk size beforehand; wherein the pool allocates one of the preserved chunks to a logical volume when the logical volume receives a write command and a chunk has not been allocated at a write location specified in the write command; and wherein the pool deallocates any preserved chunks that are unused after elapsing a predefined time.