Do not specify a partition when submitting a batch job on NY Blue/P.
Instead, specify the size of the dynamic partition that LoadLeveler should allocate for your batch job. Specify between 64 and 2048 nodes.
For example for 64 nodes, you would include the following statement in your batch script (instead of specifying #@ bg_partition):
Recall that there are four processors per node on NY Blue/P (not two as on NY Blue/L). This job would use 256 processors. See
execution process modes.
If you wish to use fewer processors than the allocated partition possesses, use -np. For example, if you wanted to
use only 4 of 256 allocated processors (wasteful unless necessary for some reason), you would include these two statements in your batch script:
In testing we noticed for
example that when 1536 nodes were requested, 2048 nodes were instead allocated. Note the following excerpts
from the Loadleveler documentation indicating that your job could be allocated more nodes than the number of nodes you requested:
bg_size is an integer indicating the size of the job in units of compute nodes...The size of the allocated shape
will be no smaller than the requested size and as close to the request size as possible...Not all values given
for bg_size are represent able.
For example, consider an 8x4x4 Blue Gene system in units of base partitions and
a requested bg_size of 5632 (equivalent to 11 base partitions). Since 11 is a prime number, it cannot be decomposed.
Furthermore, it is greater than any one dimension of the system. In this case, a 3x4x1 partition is allocated,
since it is the smallest number of base partitions larger than the requested size.
For Blue Gene technical or administrative assistance, please open a ticket with the
ITD Helpdesk by sending an email to
email@example.com or calling 631-344-5522.
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