Platform LSF Administration Guide Version 6.2

Job Slot Limits For Parallel Jobs
Administering Platform LSF
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Job Slot Limits For Parallel Jobs
A job slot is the basic unit of processor allocation in LSF. A sequential job uses one job
slot. A parallel job that has
N components (tasks) uses N job slots, which can span
multiple hosts.
By default, running and suspended jobs count against the job slot limits for queues,
users, hosts, and processors that they are associated with.
With processor reservation, job slots reserved by pending jobs also count against all job
slot limits.
When backfilling occurs, the job slots used by backfill jobs count against the job slot
limits for the queues and users, but not hosts or processors. This means when a pending
job and a running job occupy the same physical job slot on a host, both jobs count
towards the queue limit, but only the pending job counts towards host limit.