LSF Version 7.3 - Administering Platform LSF

Memory Reservation for Pending Jobs
408 Administering Platform LSF
Memory Reservation for Pending Jobs
About memory reservation for pending jobs
By default, the rusage string reserves resources for running jobs. Because resources
are not reserved for pending jobs, some memory-intensive jobs could be pending
indefinitely because smaller jobs take the resources immediately before the larger
jobs can start running. The more memory a job requires, the worse the problem is.
Memory reservation for pending jobs solves this problem by reserving memory as
it becomes available, until the total required memory specified on the
rusage string
is accumulated and the job can start. Use memory reservation for pending jobs if
memory-intensive jobs often compete for memory with smaller jobs in your cluster.
Configure memory reservation for pending jobs
RESOURCE_RESERVE parameter
1 Use the RESOURCE_RESERVE parameter in lsb.queues to reserve host
memory for pending jobs.
The amount of memory reserved is based on the currently available memory
when the job is pending. Reserved memory expires at the end of the time
period represented by the number of dispatch cycles specified by the value of
MAX_RESERVE_TIME set on the RESOURCE_RESERVE parameter.
Configure lsb.modules
1 To enable memory reservation for sequential jobs, add the LSF scheduler
plugin module name for resource reservation (
schmod_reserve) to the
lsb.modules file:
Begin PluginModule
SCH_PLUGIN RB_PLUGIN SCH_DISABLE_PHASES
schmod_default () ()
schmod_reserve () ()
schmod_preemption () ()
End PluginModule
Configure lsb.queues
1 Set the RESOURCE_RESERVE parameter in a queue defined in lsb.queues.
If both RESOURCE_RESERVE and SLOT_RESERVE are defined in the same
queue, job slot reservation and memory reservation are both enabled and an
error is displayed when the cluster is reconfigured. SLOT_RESERVE is ignored.