EREP uses the records in the VM SP error recording area as the only input (unless you use the HIST or MERGE operand). The SERLOG FILEDEF, which implies VSE or MVS guest input (ERDS), is only a simulation of that file, required because of format differences between the error recording area and the system ERDS.

The result of this can be misleading reports, because the VM SP error recording area did not contain the records that would have been on a guest system ERDS. This can be a problem especially with OBR records for your TP devices. If you only run EREP under VM, you might be missing some errors.

One way to make sure you get reports about all the possible errors in your system is to run EREP under VM SP and then run it again under each guest operating system.

Another way to make sure you are seeing all your error records in the EREP reports is to combine the data from your system’s ERDS and the error recording area before requesting any reports. Then run EREP under either system using the combined records as history input.