Running searchindex.php via command line
 

I am rebuilding search index of a very large forum with millions of posts. The rebuild takes several hours to days. Will it stop if I close the SSH client?

php searchindex.php

I think that, in part, depends on server configuration, but my guess is it will stop when the window is closed. Might want to ask your server admin though.

Maybe someone more knowledgable has a more definitive answer.

I believe that when your SSH session ended, the process will receive a signal to end itself.
To be sure, you can just run the `top` command and see if there's a PHP process running (executed as root?) that's executing the searchindex script.