1. A method for self-detecting storage bottleneck by a processor device in a computing environment, the method comprising: injecting delay commands into sequential input/output (I/O) requests and measuring effects of the injected delay commands for determining whether a storage system handling the sequential input/output (IO) requests is causing a bottleneck, delaying a processing of the sequential I/O requests for a time period when injecting a delay command, and delaying a response after processing the sequential I/O requests for a time period when injecting a delay command.