Sometime when you have a power outage on your jabber server while the service is running, you can not start jabberd. In my case it returned:

ERROR: sm died. Shutting down server.

It happened because the c2s component is trying to bind with the same hostname as sm component.

This problem can be resolved by changing the value on <id> tag on c2s.xml to any string.

More about jabberd2 can be found here.