Product specifications
Table Of Contents
- Table of Contents
- 1 Introduction
- 2 Feature Overview
- 3 Step-by-Step Cluster Setup and MPI Usage Checklists
- 4 InfiniPath Cluster Setup and Administration
- Introduction
- Installed Layout
- Memory Footprint
- BIOS Settings
- InfiniPath and OpenFabrics Driver Overview
- OpenFabrics Drivers and Services Configuration and Startup
- Other Configuration: Changing the MTU Size
- Managing the InfiniPath Driver
- More Information on Configuring and Loading Drivers
- Performance Settings and Management Tips
- Host Environment Setup for MPI
- Checking Cluster and Software Status
- 5 Using QLogic MPI
- Introduction
- Getting Started with MPI
- QLogic MPI Details
- Use Wrapper Scripts for Compiling and Linking
- Configuring MPI Programs for QLogic MPI
- To Use Another Compiler
- Process Allocation
- mpihosts File Details
- Using mpirun
- Console I/O in MPI Programs
- Environment for Node Programs
- Environment Variables
- Running Multiple Versions of InfiniPath or MPI
- Job Blocking in Case of Temporary InfiniBand Link Failures
- Performance Tuning
- MPD
- QLogic MPI and Hybrid MPI/OpenMP Applications
- Debugging MPI Programs
- QLogic MPI Limitations
- 6 Using Other MPIs
- A mpirun Options Summary
- B Benchmark Programs
- C Integration with a Batch Queuing System
- D Troubleshooting
- Using LEDs to Check the State of the Adapter
- BIOS Settings
- Kernel and Initialization Issues
- OpenFabrics and InfiniPath Issues
- Stop OpenSM Before Stopping/Restarting InfiniPath
- Manual Shutdown or Restart May Hang if NFS in Use
- Load and Configure IPoIB Before Loading SDP
- Set $IBPATH for OpenFabrics Scripts
- ifconfig Does Not Display Hardware Address Properly on RHEL4
- SDP Module Not Loading
- ibsrpdm Command Hangs when Two Host Channel Adapters are Installed but Only Unit 1 is Connected to the Switch
- Outdated ipath_ether Configuration Setup Generates Error
- System Administration Troubleshooting
- Performance Issues
- QLogic MPI Troubleshooting
- Mixed Releases of MPI RPMs
- Missing mpirun Executable
- Resolving Hostname with Multi-Homed Head Node
- Cross-Compilation Issues
- Compiler/Linker Mismatch
- Compiler Cannot Find Include, Module, or Library Files
- Problem with Shell Special Characters and Wrapper Scripts
- Run Time Errors with Different MPI Implementations
- Process Limitation with ssh
- Number of Processes Exceeds ulimit for Number of Open Files
- Using MPI.mod Files
- Extending MPI Modules
- Lock Enough Memory on Nodes When Using a Batch Queuing System
- Error Creating Shared Memory Object
- gdb Gets SIG32 Signal Under mpirun -debug with the PSM Receive Progress Thread Enabled
- General Error Messages
- Error Messages Generated by mpirun
- MPI Stats
- E Write Combining
- F Useful Programs and Files
- G Recommended Reading
- Glossary
- Index
6–Using Other MPIs
Improving Performance of Other MPIs Over IB Verbs
IB6054601-00 H 6-13
A
The maximum supported MTU size of InfiniPath adapter cards are:
QHT7140: 2K
QLE7140, QLE7240, QLE7280: 4K
Support for 4K IB MTU requires switch support for 4K MTU. The method to set the
IB MTU size varies by MPI implementation:
Open MPI defaults to the lower of either the IB MTU size or switch MTU size.
MVAPICH defaults to an IB MTU size of 1024 bytes. This can be over-ridden
by setting an environment variable:
$ export VIADEV_DEFAULT_MTU=MTU4096
Valid values are MTU256, MTU512, MTU1024, MTU2048 and MTU4096. This
environment variable must be set for all processes in the MPI job. To do so,
use ~/.bashrc or use of /usr/bin/env.
HP-MPI over IB Verbs automatically determines the IB MTU size.
Platform (Scali) MPI defaults to an IB MTU of 1KB. This can be changed by
adding a line to /opt/scali/etc/iba_params.conf, for example:
mtu=2048
A value of 4096 is not allowed by the Scali software (as of Scali
Connect 5.6.0); in this case, a default value of 1024 bytes is used. This
problem has been reported to support at Platform Inc. The largest value that
can currently be used is 2048 bytes.
Intel MPI over uDAPL (which uses IB Verbs) automatically determines the IB
MTU size.