User-based fairshare policies configured at the queue level handle resource contention among users in the same queue. You can define a different fairshare policy for every queue, even if they share the same hosts. A user’s priority is calculated separately for each queue.
To submit jobs to a fairshare queue, users must be allowed to use the queue (USERS in lsb.queues) and must have a share assignment (FAIRSHARE in lsb.queues). Even cluster and queue administrators cannot submit jobs to a fairshare queue if they do not have a share assignment.
If the default user group set in DEFAULT_USER_GROUP (lsb.params) does not have shares assigned in a fairshare queue, jobs can still run from the default user group, and are charged to the highest priority account the user can access in the queue. The default user group should have shares assigned in most fairshare queues to ensure jobs run smoothly.
Job submitted with a user group (bsub -G) which is no longer valid when the job runs charge the default user group (if defined) or the highest priority account the user can access in the queue (if no default user group is defined). In such cases bjobs -l output shows the submission user group, along with the updated SAAP (share attribute account path).
By default, user share accounts are created for users in each user group, whether they have active jobs or not. When many user groups in the fairshare policy have all as a member, the memory used creating user share accounts on mbatchd startup may be noticeable. Limit the number of share accounts created to active users (and all members of the default user group) by setting LSB_SACCT_ONE_UG=Y in lsf.conf.