Configuring multiple license server hosts is optional. It provides a way to keep LSF running if a license server host goes down. There are two ways to configure multiple license servers.
A permanent license key is tied to a particular license server host with a specific host ID. If that host is down, the license service is not available and LSF becomes unlicensed if the master LIM is shut down or restarted.
To prevent down time, you can configure three hosts as license server hosts. The license server daemon (lmgrd) and LSF vendor license daemon (lsf_ld) run on each license server host. With three redundant server hosts, if any one host is down, the other two continue to serve licenses. If any two hosts are down, the license service stops.