Sun HPC ClusterTools 3.0 Administrator's Guide: With LSF

Set PRIORITY in lsb.queues

The PRIORITY parameter defines a batch queue's priority relative to other batch queues. To ensure faster dispatching, assign a higher PRIORITY value to interactive batch queues than you give to noninteractive queues. A higher number equals a higher priority. For example, the following setting

PRIORITY=12
means that jobs on that queue will usually be serviced sooner than
jobs on queues with a setting of PRIORITY=11 or lower.