Concept Guide

Benchmarks and test tools
29 Dell EMC Ready Solutions for HPC BeeGFS High Performance Storage | ID 460
BeeGFS Tuning Parameter
Description
-O
String of IOR directives
-o
path to file for the test
-s
Segment count
-g
intraTestBarriers - use barriers between open, write/read, and close
-t
Transfer size
-b
Block size (amount of data for a process)
A.3 MDtest
MDtest is used with mpirun. For these tests, OpenMPI version < > was used. The command used to run the
MDtest is given below:
mpirun -machinefile $hostlist --map-by node -np $threads ~/bin/mdtest -i 3 -b
$Directories -z 1 -L -I 1024 -y -u -t -F
The following table describes the MDtest command-line arguments.
Appendix A — MDtest command line arguments
mpirun Argument
Description
-machinefile
Tells mpirun where the hostfile is located
-map-by node
Launch processes one per node, cycling by node in a round robin fashion. This
spreads processes evenly among nodes and assigns MPI_COMM_WORLD ranks
in a round-robin, “by-node” manner.
-np
Number of processes
Mdtest Argument
Description
-d
The directory MDtest should run in
-i
The number of iterations the test will run
-b
Branching factor of directory structure
-z
Depth of the directory structure
-L
Files only at leaf level of tree
-I
Number of files per directory tree
-y
Sync the file after writing
-u
Unique working directory for each task
-C
Create files and directories
-R
Randomly stat files
-T
Only stat files and directories
-r
Remove files and directories left over from run