1. A method of performing dynamic binding of device identifiers to data storage devices comprising: receiving a first device identifier that is assigned to an application on a host at a first point in time without having the first device identifier bound to any data storage device, said application having its data stored on a data storage system, said first device identifier being a unique detachable device identifier dynamically bound to different data storage devices at different points in time in accordance with data storage devices used by the application, wherein said first identifier is assigned to the application at the first point in time and is not bound to any data storage device at the first point in time thereby not identifying any data storage device; attaching the first device identifier to a first data storage device of the data storage system, said first data storage device including a first set of data used by the application, wherein said attaching the first device identifier to the first data storage device is performed subsequent to the first point in time and includes updating information on the data storage system to associate the first device identifier with a first data storage system internal identifier used locally by the data storage system to identify the first data storage device and makes the first data storage device available for data operations from the application; detaching the first device identifier from the first data storage device thereby making the first data storage device unavailable for data operations from the application; and attaching the first device identifier to a second data storage device that is different from the first data storage device, said second data storage device including a second set of data used by the application at a second point in time, said attaching the first device identifier to the second data storage device making the second data storage device available for data operations from the application.