Efficient Flashcopy backup and mount, clone, or restore collision avoidance using dynamic volume allocation with reuse and from a shared resource pool

For efficient Flashcopy backup and a mount, clone, instant restore, and/or file level restore task collision avoidance using dynamic volume allocation with reuse and from a shared resource pool, performing at least one attempt to reuse an existing FlashCopy target volume in a Flashcopy chain of target volumes that is not currently being used for at least one of the mount task, the clone task, instant restore task, and/or file level restore task at the same time for a FlashCopy backup. If the at least one attempt to reuse the existing FlashCopy target volume fails, dynamically allocate a new Flashcopy target volume for the Flashcopy backup from a global pool of Flashcopy backup target volumes shared by a plurality of device classes.