Maintaining an online mirror site

Hi all,

What I’m trying to accomplish here is to have two sites with exactly the same content, updated either manually by import/export or automatically. I currently have one main site which all my readers visit, but it may occasionally go down, or I might put it in maintenance mode for some changes. During that time, I still want my users to be able to access my content. (commenting and likes not required on mirror site)

I’m essentially looking for a mirror or cache sort of feature since my second site is a subdomain which is hosted on another server. Currently, I do an export/import every few days, but I was hoping that another solution was possible. As far as I’m aware, network sites will not work for me because all of the data is still stored on one server, which means that it can’t be accessed if it is down.

All advice appreciated.