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Dell HPC NFS Storage Solution High Availability Configurations with Large Capacities
78
IOzone IOPs Random Access (Reads and Writes)
# /usr/sbin/iozone -i 2 -w -r 4k -I -O -w -+n -s 2G -t 1 -+m ./clientlist
By using -c and -e in the test, IOzone provides a more realistic view of what a typical application is
doing. The O_Direct command line parameter allows us to bypass the cache on the compute node on
which we are running the IOzone thread.
B.2. mdtest
mdtest can be downloaded from http://sourceforge.net/projects/mdtest/. Version 1.8.3 was used in
these tests. It was compiled and installed on a NFS share that was accessible by compute nodes.
dtest is launched with mpirun. For these tests, MPICH2 version 1.3.2 was used. The following table
describes the mdtest command line arguments.
mpirun ARGUMENT
DESCRIPTION
-np
Number of Processes
--nolocal
Instructs mpirun not to run locally
--hostfile
Tells mpirun where the hostfile is
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