Techniques are provided for distributing data. It is determined that a
source storage device is becoming a bottleneck. One or more blocks to be
moved from the source storage device to one or more other storage-devices
are identified. The one or more other storage devices are selected. Copy
services are used to move the blocks from the source storage device to
the one or more other storage devices. A metadata store is updated with
locations of the blocks that have been moved.