Re-install aio with an existing data dir

I had AIO installed and running with its data on a separate partition. However the OS did not work as I would like to, so I thought that I could just re-install the OS and after that re-install AIo and just point it to the existing data dir.

Well, stupid idea, it does not work that way.

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Is there any way to install aio again and use the existing data dir? Without having to restore everything from a backup. It takes ages to get the data into nextcloud with the migration app.

Hi, see