Darius is a 32-node cluster with InfiniBand QDR interconnections. It runs CentOS 5.4 (Linux kernel version 2.6), which is closely related to Red Hat Enterprise Linux.
Its hostname is darius1.csbi.mit.edu. The CSBi firewall is configured to accept connections only from MIT IP addresses, so users should connect to MITNet through MIT VPN for off-campus use.
Installed software
software | location of source code or executable |
|---|---|
NAMD 2.7b2 | /share/apps/NAMD_2.7b2_Source/Linux-x86_64-OpenMPI |
Charm++ 6.2 | /share/apps/charm-6.2.0/mpi-linux-x86_64-mpicxx |
VMD 1.8.7 | /share/apps/vmd-1.8.7/LINUXAMD64 |
AmberTools 1.4 | /share/apps/amber11 |
CHARMM c35b2 | not yet installed, source in /share/apps/c35b2 |
GNUPLOT 4.0 | /usr/bin/gnuplot |
Grace 5.1 | /usr/bin/xmgrace |
Octave 3.0.5 | /usr/bin/octave |
GROMACS-MPI 4.0.7 | /usr/bin/g_mdrun_mpi |
The OpenMPI, Mvapich, and Mvapich2 libraries all use the Infiniband interface.
libraries | location |
|---|---|
OpenMPI | /usr/mpi/gcc/openmpi-1.4.1 |
Mvapich | /usr/mpi/gcc/mvapich-1.2.0 |
Mvapich2 | /usr/mpi/gcc/mvapic2-1.4.1 |
Platform MPI, aka HP-MPI | /opt/hpmpi |
Note that the mpicc, mpicxx, mpif77, mpif90, etc., all refer to the OpenMPI versions, when using the default path.
Performance
Using the 92 katom ApoA1 benchmark with NAMD 2.7, performance appears to compare very favorably with previously benchmarked clusters: its [processor cores X time per step] values (corresponding to the ordinate on the figure on the linked page) vary from 1.8 sec (8 CPUs) to 2.1 sec (128 CPUs).
Using the queue system
All programs run on Darius must use the queue system. Users can check what jobs are running using qstat; XWindows users can try xpbs, although load times are long. Users can submit their jobs using the qsub command:
...
| Code Block |
|---|
#!/bin/bash #PBS -k o #PBS -N apoa #PBS -l nodes=1:ppn=4,walltime=12:00:00 #PBS -j oe cd /home/musolino/namd/apoa1 h4. Notes on compiling NAMD 2.6 # Run {{./config /usr/mpi/gcc/openmpi-1.4.1/bin/mpirun /share/apps/NAMD_2.7b2_Source/Linux-x86_64-OpenMPI/namd2 apoa1.namd |
Notes on compiling NAMD 2.6
- Run
./config Linux-amd64-MPI.
...
<postfix>to
...
- create
...
- an
...
- installation. <Postfix> is any label you wish to append to the NAMD directory.
- The new Charm++
...
- and
...
- NAMD
...
- 2.7
...
- use
...
- different
...
- platform
...
- names than they did in the past(e.g.
...
Linux-x86_64-OpenMPI
...
- for
...
- NAMD
...
- 2.7 and Charm++ 6.2,
...
- but
...
Linux-amd64-MPI
...
- for
...
- NAMD
...
- 2.6.
...
- This
...
- causes
...
- problems
...
- when
...
- looking
...
- for
...
- the
...
- Charm++
...
- installation,
...
- so
...
- edit
...
Make.charm
...
- in
...
- NAMD
...
- directory:
Code Block
...
CHARMBASE = /share/apps/charm-6.2.0/mpi-linux-x86_64-mpicxx
...
...
- Then
...
- edit
...
Makearch
...
- in
...
- the
...
Linux-amd64-MPI.postfix
...
- directory
...
- as
...
- follows,
...
- by
...
- changing
...
- the
...
CHARM=...
...
- line:
Code Block
...
include .rootdir/Make.charm
...
include .rootdir/arch/Linux-amd64-MPI.arch
...
CHARM = $(CHARMBASE)
...
NAMD_PLATFORM = $(NAMD_ARCH)-MPI
...
include .rootdir/arch/$(NAMD_ARCH)$(NAMD_SUBARCH).base
...
- Try
...
make
...
- in
...
- the
...
- installation
...
- directory.
Other notes
Using the Mac OS 10.6 X11 client, XWindows is working, with small utilities like xcalc and xpbs, and with VMD 1.8.7. VMD performance seems sluggish, however. Note: when connecting with "ssh -X", starting VMD consistently leads to a crash of the X11 client. Connecting with "ssh -Y" (which disables X11 security protocols, for trusted connections) works instead. This problem has occurred with other computers in the past, and it's not clear whether this is a bug in VMD, the X11 installation on the cluster, or the Mac OS 10.6 X11 client.