I did it plenty of times with journals that arrive to us from external services and I don’t have any fancy tooling to do the job (and I don’t need it).
Not sure why this petition is recurrent in the forum… as far as the process is as simple (or complex) as duplicate your OJS installation, and remove all journals except the one you like to isolate. If you have 10 journals… you will need to do this 9 times.
After deleting one journal, what would be the article id. Will it be same? Or they rearrange from 1.
Article IDs assigned won’t change.
If an old article had the id 298 it will keep been 298.
Can you tell how to redirect the users, who are trying to visit an article in the old domain to the same article on new domain.
It need to be done at webserver/proxy level with redirection rules.
How does this affect indexing on google and Google scholar. Do they index again with out any duplicate content issues.
If you keep the URLs intact, it won’t make any difference.