LSF Version 7.3 - Administering Platform LSF

Administering Platform LSF 287
Specifying Resource Requirements
Specifying exclusive resources
An exclusive resource may be used in the resource requirement string of any
placement or scheduling command, such as
bsub, lsplace, lsrun, or lsgrun. An
exclusive resource is a special resource that is assignable to a host. This host will not
receive a job unless that job explicitly requests the host. For example, use the
following command to submit a job requiring the exclusive resource
bigmem:
bsub -R "bigmem" myjob
Jobs will not be submitted to the host with the bigmem resource unless the
command uses the
-R option to explicitly specify "bigmem".
To configure an exclusive resource, first define a static Boolean resource in
lsf.shared. For example:
Begin Resource
...
bigmem Boolean () ()
End Resource
Assign the resource to a host in the Host section of lsf.cluster.cluster_name.
Prefix the resource name with an exclamation mark (!) to indicate that the resource
is exclusive to the host. For example:
Begin Host
HOSTNAME model type server r1m pg tmp RESOURCES RUNWINDOW
...
hostE ! ! 1 3.5 () () (linux !bigmem) ()
...
End Host
Order String
The order string allows the selected hosts to be sorted according to the values of
resources. The values of
r15s, r1m, and r15m used for sorting are the normalized
load indices returned by
lsload -N.
The order string is used for host sorting and selection. The ordering begins with the
rightmost index in the order string and proceeds from right to left. The hosts are
sorted into order based on each load index, and if more hosts are available than
were requested, the LIM drops the least desirable hosts according to that index. The
remaining hosts are then sorted by the next index.
After the hosts are sorted by the leftmost index in the order string, the final phase
of sorting orders the hosts according to their status, with hosts that are currently not
available for load sharing (that is, not in the
ok state) listed at the end.
Because the hosts are sorted again for each load index, only the host status and the
leftmost index in the order string actually affect the order in which hosts are listed.
The other indices are only used to drop undesirable hosts from the list.
When sorting is done on each index, the direction in which the hosts are sorted
(increasing vs. decreasing values) is determined by the default order returned by
lsinfo for that index. This direction is chosen such that after sorting, by default,
the hosts are ordered from best to worst on that index.