If you are writing an application for a DASD-only log stream, you must keep in mind that a DASD-only log stream is single-system in scope, meaning that only one system at a time can connect to a DASD-only log stream. (See The log stream for a description of the two different types of log streams.) Multiple applications from the same system can connect to a DASD-only log stream, but only from one system at a time. An application trying to connect to a DASD-only log stream that already has another system connected will fail. A second system cannot connect to the DASD-only log stream until the first one disconnects.
The ANSAA_DASDONLYLOGSTREAM flag in the IXGANSAA mapping macro indicates whether a log stream is DASD-only.
When an application issues the IXGCONN request to connect to a DASD-only log stream, the STUCTNAME, AVGBUFSIZE, and ELEMENTSIZE will be returned containing hexidecimal zeros, because they are all coupling facility structure related fields.