System Abends

As mentioned earlier there are two types of these although they stem from different components.

Program Interrupts, the next topic, are generated by the hardware, whereas true System Abends will be generated by the Operating System, when it is unable to comply with an SVC request.

In Assembler SVC (Supervisor Call) usage is often masked by the use of Macros and in higher level languages such as COBOL and PLI they are implicit in statements such as OPEN, CLOSE and dynamic CALL, to name a few.

It is possible to trap these Abends using ESTAE/ESTAEX Exit Routines.

Some common System ABENDS

Code	SVC	z/OS Service
Sx06	06	LINK processing, i.e. passing control to program
Sx0A	10	GET and FREE Storage (Memory) within the REGION
Sx13	19	File OPEN processing
Sx14	20	File CLOSE processing
Sx22	34	CANCEL, with the lead digit indicating the type of cancellation.
Sx37	55	End of Volume processing

The SVC numbers in the above table are the decimal equivalents of the last two digits of the ABEND code. The actual codes are listed in the IBM System Codes manual, which often refers to the associated message, and the System Messages Manual will describe the various Reason Codes.

The leading digit of the ABEND code aids further analysis; for instance S013 is a general OPEN failure, S213 relates to disks, and S813 relates to cartridge.