Osm pbf for the entire earth

I am trying to serve my own tiles and using the https://download.geofabrik.de/ pbf files, how can I concatenate or merge them to get a single world pbf?

I tried osmium to cat or merge and that did not work for me when I tried to create a docker image from the instructions on Using a Docker container – Switch2OSM

Any advice appreciated!

If you want the entire planet, you may be better off using the Planet file directly.

Thanks so much! I did look at the entire planet and it is 74GB! If I want a couple of subsets of countries is it still possible to load 2 or 3 selected regions and serve them for size constraint reasons?