I guess it depends on what you mean by migrate.
What you can do is set up a new environment, import all your custom content and then move the agents from one server to another. I have done this before and it worked great.
I have also done it where we brought up a new server with the same hostname and restored the data from the SQL server on the old system to the new system. But this was from Windows to windows.
I have not seen anything for doing this from Windows to Linux even with SQL. I tried to check from my phone, but from what I can see, SQL is not supported on Linux (at least not for bigfix)