Instant virtual copy operations are adapted for data objects that span
storage boundaries such as logical and/or physical DASD subsystems.
Initially, a data storage system receives a request to copy a data object
contained in the system. The storage system includes multiple storage
regions separated by storage boundaries. The regions may correspond to
logical or physical DASD subsystems, for example. The storage system
determines whether the data object resides in more than one of these
regions. If so, the storage system divides the data object into multiple
subparts, each subpart contained within a single storage region. Then, the
storage system separately performs an instant virtual copy operation for
each subpart. On the other hand, if the data object already resides in a
single one of the regions, the storage system can perform one instant
virtual copy operation for the data object as a whole.
