*Revised* Infiniband Policy for Biowulf Cluster (Biowulf)

This announcement is directed primarily to users of
the Infiniband network on the NIH Biowulf Cluster.

In response to comments from several users, we have
revised the IB-usage policy first announced Apr 1.
There will no longer be a minimum allocation of 32
nodes.  No changes to the way jobs are submitted are
required.

Jobs will be automatically directed to one of two
pools, one reserved for "large" (64-128 processor)
jobs, and one reserved for "small" (<64 processor)
jobs. The systems staff will be able to dynamically
adjust the size of the pools to allow for demand.

You can determine the total number of processors in
each pool by using the 'batchlim' command:

$ batchlim
(only the relevant lines are shown here)
          Max CPUs   Max CPUs
          Per User   Available
         ---------- -----------
ib2         48         74
ib          128        196

The "ib2" pool is for small jobs, the "ib" pool
for large jobs.  The batchlim output shows that
there are 196 and 74 processors respectively
assigned to the ib and ib2 pools.  The maximum
per-user limits are 128 and 48 processors
respectively.