Aspects of the present disclosure relate to improving response rates of input/output (IO) requests targeting undefined virtual storage devices. In embodiments, an (IO request can be received by a storage array. Additionally, a determination of whether the IO request targets an undefined target track can be made. Further, source data related to the IO request can be located. For instance, a direct image lookup (DIL) can be performed to locate the source data. Also, a storage-related operation on the undefined target track can be performed using instructions provided by the IO request, such as updating a version of the undefined track. Further, a storage resource allocation for the undefined target track can be destaged.