Pattern search request embedded in a transport mode command word for a channel subsystem in a storage system

Provided are a computer program product, system, and method for processing request directed through a channel subsystem to a storage server. In one embodiment, a pattern search request is embedded in a Device Command Word (DCW) which allows the storage server to do all or substantially all of the search and comparison work in response to as few as a single DCW from the host. In addition, I/O processing can be enhanced to use the target record of interest of a successful embedded pattern search request as the starting point for read/write I/O processing, all in response to as few as a single DCW. Still further, orientation rules can also be relaxed such that once a target record is found, any and all fields of the record can be accessed and utilized in execution of subsequent commands of the initial or subsequent DCWs of the chain.