From Mods Repository Wiki
In order to run custom maps on Linux Server please make sure you have the latest Binaries installed, you can find them HERE.
- Some maps do have issues with Minimap, make sure you have the very latest versions of those maps and that they have the minimap issue resolved.
- For this workaround, you must have access to the zone/english directory of the game on your server
- Place a copy of the localized_mp_custommap.ff file in your zone/english directory - mp_custommaps being the map name of course.
Example for mp_marsh
In this case the localized_mp_marsh.ff and the localized_mp_ambush.ff file need to be copied into the zone/english directory on the server
this way the custom maps do run on linux and can get fast downloaded by http-redirect it will NOT be downloaded in the clients zone/english directory but in the normal usermaps folder as it should..so there is no cluttering at the clientside