Installation guide

QLogic OFED+ Host Software Page 13 of 14
 An SRP write performance bug between QLE7240/QLE7280 and LSI (Engenio) storage
systems was fixed. To apply this fix, modify the srp_sg_tablesize and max_sect
parameters. To modify srp_sg_tablesize, do one of the following:
 Add the following line to /etc/modprobe.conf:
options ib_srp srp_sg_tablesize=80
 Define srp_sg_tablesize when adding the ib_srp module (as root):
modprobe ib_srp srp_sg_tablesize=80
 If using srp_daemon, modify max_sect by adding the following command to
/etc/srp_daemon.conf file:
a id_ext=200500A0B81146A1,ioc_guid=00a0b80200402bef,max_sect=2048
 To ensure proper operation of MPI, the QLogic OFED+ INSTALL sets the memory locking
limits in the /etc/security/limits.conf file to unlimited, due to the large amounts of
memory needed to run the MPIs. Open MPI recommends using unlimited ulimits for
lockable memory. For more information, see:
http://www.open-mpi.org/faq/?category=openfabrics#ib-locked-pages
An alternative is to use the --mca mpi_leave_pinned 1 option with mpirun.
 When users increase the number of processes beyond the number of open files allowed
by ulimit, mpirun prints an error message. The ulimit for the number of open files is
typically 1024 on both Red Hat and SLES. The message will look similar to the following:
MPIRUN.up001: Warning: ulimit for the number of open files is only 1024,
but this mpirun request requires at least number of files open files
(sockets). The shell ulimit for open files needs to be increased. This is
due to limit:
descriptors 1024
The ulimit can be increased; QLogic recommends an increase of approximately 20
percent over the number of CPUs. For example, in the case of 2048 CPUs, ulimit could
be increased to 2500: ulimit -n 2500. Increase the ulimit only on the host where
mpirun was started, unless the mode of operation allows mpirun from any node.