You do have to be root and the command is either "/etc/init.d/metalayer-crawler0 start" or "/etc/init.d/metalayer-crawler0 restart" depending upon whether you are starting it for the first time or attempting to kill a currently running one and restarting it. "restart" is generally safe thing to do even if you do not have one running currently.

I have been noticing media player is not picking the new music any more for me. My first though was metacrawler is not running. So I restarted it and it still did not show up in "ps -ef". I tried starting it by running it directly from /usr/bin with "-F" to run it in foreground and it fails with segmentation fault! So now any of the new music since it ran successfully last is not being indexed. Any one else seeing this?