An invention is provided for handling target disk access requests during disk defragmentation in a solid state drive caching environment. The invention includes detecting a request to access a target storage device. In response, data associated with the request is written to the target storage device without writing the data to the caching device, with the proviso that the request is a write request. In addition, the invention includes reading data associated with the request and marking the data associated with the request stored in the caching device for discard, with the proviso that the request is a read request and the data associated with the request is stored on the caching device. Data marked for discard is discarded from the caching device when time permits, for example, upon completion of disk defragmentation.