LSF Version 7.3 - Administering Platform LSF

Administering Platform LSF 505
Running Parallel Jobs
If PARALLEL_SCHED_BY_SLOT=Y in lsb.params, the span string is used to control
the number of job slots instead 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.
◆ Predefined ptile value with optional multiple ptile values, per host type or
host model:
❖ For host type, you must specify same[type] in the resource requirement.
In the following example, the job requests 8 processors on a host of type
HP
or
SGI, and 2 processors on a host of type LINUX, and the predefined
maximum job slot limit in
lsb.hosts (MXJ) for other host types:
span[ptile='!',HP:8,SGI:8,LINUX:2] same[type]
❖ For host model, you must specify same[model] in the resource
requirement. In the following example, the job requests 4 processors on
hosts of model
PC1133, and 2 processors on hosts of model PC233, and the
predefined maximum job slot limit in
lsb.hosts (MXJ) for other host
models:
span[ptile='!',PC1133:4,PC233:2] same[model]
span[hosts=-1] Disables span setting in the queue. LSF allocates the required processors for the job
from the available set of processors.
Specifying multiple ptile values
In a span string with multiple ptile values, you must specify a predefined default
value (
ptile='!') and either host model or host type.
You can specify both type and model in the
same section in the resource
requirement string, but the
ptile values must be the same type.
If you specify
same[type:model], you cannot specify a predefined ptile value (!)
in the
span section.
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).