PREALLOCATING STORAGE SPACE FOR AN APPLICATION OPERATION IN A SPACE EFFICIENT VOLUME

Provided are a computer program product, system, and method for pre-allocating storage space for an application operation in a space efficient volume where a host system transmits writes to the space efficient volume. Physical storage space is allocated to the space efficient volume when the host system submits a write request. An amount of space needed by the write request is allocated to the volume in response to receiving the write request. A space allocation request is received from the host system for an application operation indicating a requested amount of space to allocate in the space efficient volume for the application operation. The requested amount of space is pre-allocated in the space efficient volume for the application operation in advance of the application operation needing the requested amount of space for a series of write operations that will be generated during the execution of the application operation.