If you have a dump resulting from an ABEND0C4 in load module IDA019L1, or a console dump of a wait or loop with the PSW pointing into load module IDA019L1, then you can find the data set name (DSN) in the area pointed to by register 3. In most cases, Register 3 points to the AMB, and the data component name appears at offset X'88' into the AMB.
If you suspect a wait or loop in record management and the registers
do not point into load module IDA019L1 (indeed, the symptoms of the
dump seem to indicate a problem external to record management, for
example, CICS® waits), you can
locate the AMB by using the RPL. Figure 1 shows
how to do this:
Figure 1. VSAM
Record Management—How to Find a Damaged Data Set
Note: Because of its dependency on design and implementation, the
control block offsets may change in new product releases or versions
as a result of service.
RLS has a different structure. The user's RPL at RPL+4 points to another RPL in the VSAM server address space. The ACB, AMBL, and AMB are all in the VSAM server address space.