Concept Guide

Performance Characterization
20 Dell EMC Ready Solutions for HPC BeeGFS High Performance Storage | ID 460
allocated each thread on a different node, using round robin to spread them homogeneously across the 32
compute nodes.
mpirun -machinefile $hostlist --map-by node -np $threads ~/bin/mdtest -i 3 -b
$Directories -z 1 -L -I 1024 -y -u -t -F
Since performance results can be affected by the total number of IOPs, the number of files per directory and
the number of threads, consistent number of files across tests was chosen to be able to compare them on
similar grounds. The total number of files is ~ 2M in powers of two (2^21 = 2097152). The number of files per
directory was fixed at 1024, and the number of directories varied as the number of threads changed as shown
in Table 3. Figure 13 shows the metadata performance using empty (i.e. 0 KB) files.
MDtest distribution of files on directories
Number of Threads Number of files per
directory
Number of directories
per thread
Total number of files
1
1024
2048
2,097,152
2
1024
1024
2,097,152
4
1024
512
2,097,152
8
1024
256
2,097,152
16
1024
128
2,097,152
32
1024
64
2,097,152
l64
1024
32
2,097,152
128
1024
16
2,097,152
256
1024
8
2,097,152
512
1024
4
2,097,152
1024
1024
2
2,097,152
2048
1024
1
2,097,152