If I/O accesses from hosts converge on particular data drives, the hosts might experience slower response times. You can overcome this situation by using Volume Migration to migrate high-usage volumes to low-usage or faster drives. Using Volume Migration you can balance workloads across drives and across the drive processors that control I/Os.
Migrating volumes with Volume Migration is completely nondisruptive. The data being migrated can remain online to all hosts for read and write operations throughout the entire migration process.