The messages -
ADSDM126 3612 OPEN ERROR DD=ARCHIVER DSN=archvol.dsn OPEN CODE=00 CONTINUING
ADSDM221*0230 dsname NOT MERGED - OPEN ERROR ON ARCHIVE VOLUME vvvvvv
are related to the message -
The IEC149I 813-04 message indicates that an OPEN macro instruction was issued for a data set on magnetic tape,
but the data set name on the header label did not match that in the JFCB.
So it seems the tape has been overridden and does no longer contain what CA Disk is expecting.
Determine what should be on the tape from the CA Disk perspective (as per Files Data Set)by reviewing the corresponding LISTV VOL=vvvvvv and LISTD VOL=vvvvvv reports.
Check the tape from the tape management perspective (e.g. CA 1).
Check if sysparm TMSCTLEX is correctly set (e.g. to ADSTH014 for CA1) to use the interface to the External Data Manager (EDM).
In this case the tape was overridden because TMSCTLEX was not set.