LSF Version 7.3 - Administering Platform LSF

Span String
292 Administering Platform LSF
host is not overloaded. When LIM makes a placement advice, external load indices
are not considered in the resource usage string. In this case, the syntax of the
resource usage string is
res[=value]:res[=value]: ... :res[=value]
res
is one of the resources whose value is returned by the lsload command.
rusage[r1m=0.5:mem=20:swp=40]
The above example indicates that the task is expected to increase the 1-minute run
queue length by 0.5, consume 20 MB of memory and 40 MB of swap space.
If no value is specified, the task is assumed to be intensive in using that resource. In
this case no more than one task will be assigned to a host regardless of how many
CPUs it has.
The default resource usage for a task is
r15s=1.0:r1m=1.0:r15m=1.0. This
indicates a CPU-intensive task which consumes few other resources.
Span String
A span string specifies the locality of a parallel job. If span is omitted, LSF allocates
the required processors for the job from the available set of processors.
Syntax
The span string supports the following syntax:
span[hosts=1] Indicates that all the processors allocated to this job must be on the same host.
span[ptile=value] Indicates the number of processors on each host that should be allocated to the job,
where value is one of the following:
◆ Default ptile value, specified by n processors. In the following example, the
job requests 4 processors on each available host, regardless of how many
processors the host has:
span[ptile=4]
◆ Predefined ptile value, specified by ’!’. The following example uses the
predefined maximum job slot limit
lsb.hosts (MXJ per host type/model) as
its value:
span[ptile='!']
TIP: If the host or host type/model does not define MXJ, the default predefined ptile value is
1.
RESTRICTION: Under bash 3.0, the exclamation mark (!) is not interpreted correctly by the
shell. To use predefined ptile value (ptile='!'), use the +H option to disable '!' style history
substitution in bash (sh +H).
◆ Predefined ptile value with optional multiple ptile values, per host type or
host model: