A method is provided for a data storage system to change the RAID type, the layout characteristics, and the performance characteristics of a virtual volume mapped to logical disk regions in one or more logical disks while the data storage system remains online to a host. Another method is provided for a data storage system to consolidate space in one or more logical disks mapped to a virtual volume while the data storage system remains online to a host. The one or more logical disks can be consolidated to free unused chunklet regions for use in other logical disks.