Hi Kwok Ho,
to you questions:
- if you leave the storage system blank, then the files are not archived and are located in the logical path on the server file system. Therefore there is no button "Storage Syst" because there is no repository to store files in. That is not recommended on an productive system but it may be the standard setting in SARA customizing.
- I believe "A2" is standard setting from SAP. You have either to create an A2 repository on your archiving server and change the settings in OAC0 or you take any other existing repository that exists on your archive server and is customized in OAC0.
- The ARCHIVE/ARCHIVE setting in OAC3 is used by file name exit FILENAME_EXIT_ARCHIVELINK (used in some standard logical file names). I recommend to use an own logical file name, e. g. with physical file "<SYSID>_<CLIENT>_<PARAM_3>_<DATE>_<TIME>.ADK". <PARAM_3> is resolved to the name of the actual archiving object.
Regards,
Benedikt