Existence of DDM file and remote file
A file on a target server cannot be accessed for any type of operation (such as open, read, write, or display) unless a DDM file associated with the remote file already exists on the source server.
However, the remote file does not need to exist at the time that the DDM file is created or changed using the Create DDM File (CRTDDMF) command or the Change DDM File (CHGDDMF) command, because the remote file is not referred to until the DDM file is actually opened for access.
Parent topic:
Access files with DDM