With deferred writes of buffers, a processing program continues after its PUT request has been completed, even though the buffer has not been written. The processing program is not synchronized with a physical error that occurs when the buffer is finally written. A processing program that uses MRKBFR MARK=OUT is also not synchronized with a physical error. An EXCEPTION or a SYNAD routine must be supplied to analyze the error.

The ddname field of the physical error message identifies the data set that was using the buffer, but, because the buffer might have been released, its contents might be unavailable. You can provide a JRNAD exit routine to record the contents of buffers for I/O errors. It can be coordinated with a physical error analysis routine to handle I/O errors for buffers whose writing has been deferred. If a JRNAD exit routine is used to cancel I/O errors during a transaction, the physical error analysis routine will get only the last error return code. See SYNAD Exit Routine to Analyze Physical Errors and JRNAD Exit Routine to Journalize Transactions for information about the SYNAD and JRNAD routines.