Hi,
Storage DRS Balance your storage space and I/O load.
Copy paste from VMware Blog
Storage DRS continuously balances storage space usage and storage I/O load and avoids resource bottlenecks to meet application service levels and increases manageability of storage at scale. Storage DRS allows you to:
- Easily deploy additional storage capacity and seamlessly take advantage of additional capacity when new storage is added to a pool of storage volumes
- Maintain datastores in a non-disruptive manner
- Improve service levels for all applications
- Increase vSphere administrators' productivity by allowing them to monitor and manage additional infrastructure
http://www.vmware.com/products/datacenter-virtualization/vsphere/storage-drs.html
Regards
Mohammed