iRODS server can be started manually with irodsctl start and stopped with irodsctl stop. There are also istart, istop and irestart commands which start, stop or restert the iRODS servier but not the iCAT.
You can use start/stop script provided by Benedikt von St. Vieth to autostart the service upon restart of the host machine. Current status of the server can be checked with irodsctl status. iRODS performs its own logging, results can be found in iRODS/server/logs. A possibility to find out if a iRODS server is running is to use telnet and connect to iRODS control port, for instance:
telnet irodsHost 1247
This option is especially useful to check if the firewall on the remote site is configured correctly.