What causes an S300-04 abend in the CA View started task and how can it be avoided ?
A S300-04 can be caused by EXCP I/O to the Forward Recovery Dataset if it is spanning multiple DASD volumes.
CA View is doing relative block positioning on the FRDS dataset, therefore, it cannot span volumes. The entire dataset must reside on one volume.
To avoid this situation, ensure that normal z/OS allocation is being used. This allocates all extents on one volume.
Do not use any allocation routines that bypass z/OS.