Tape volume switching errors

When a program uses QSAM to read a spanned multivolume file, if it issues an FEOV macro and the first segment on the new volume is not the first segment of a record, errors may occur when the next GET macro is issued. Such errors will cause control to be passed to the error analysis exit (SYNAD).

During tape volume switching, if the user fails to mount a new tape (either through a CANCEL command for the mount request or if no response is made to the tape mounting subsystem so that the mount request processing times out), then the CMS system processing will consider the mount failure as an irrecoverable I/O error and force a SYNAD (as specified on the DCB macro) or system ABEND exit to end processing. If the user application contains a SYNAD exit, then that routine will receive control on error termination. Otherwise, the default is to enter a system ABEND exit.