The Shared (General) Farm consists of several physical clusters that are available to all SLAC users. The cluster hardware was purchased incrementally over several years by various stakeholder groups. Each physical cluster is based on a specific hardware model but all hosts in the farm run 64bit RHEL/Centos6. The LSF "general" queues feed user's jobs to the shared farms. The stakeholders have associated LSF user groups with a fairshare (scheduling priority) that reflects their cluster investment. This ensures that stakeholders will always get some runtime on the cluster when utilization is high. Users that are not members of stakeholder groups still have the ability to run jobs "for free". There is a superset fairshare group "AllUsers" that includes all SLAC users. A non-stakeholder must compete for priority with all other users running jobs on the shared farm. This may be acceptable for some, but production environments may demand priority scheduling.
They are automatically members of the "AllUsers" group - a superset that encompasses all SLAC users.