White Papers
Table Of Contents
- Executive Summary (updated May 2011)
- 1. Introduction
- 2. Dell NFS Storage Solution Technical Overview
- 3. NFS Storage Solution with High Availability
- 4. Evaluation
- 5. Performance Benchmark Results (updated May 2011)
- 6. Comparison of the NSS Solution Offerings
- 7. Conclusion
- 8. References
- Appendix A: NSS-HA Recipe (updated May 2011)
- A.1. Pre-install preparation
- A.2. Server side hardware set-up
- A.3. Initial software configuration on each PowerEdge R710
- A.4. Performance tuning on the server
- A.5. Storage hardware set-up
- A.6. Storage Configuration
- A.7. NSS HA Cluster setup
- A.8. Quick test of HA set-up
- A.9. Useful commands and references
- A.10. Performance tuning on clients (updated May 2011)
- A.11. Example scripts and configuration files
- Appendix B: Medium to Large Configuration Upgrade
- Appendix C: Benchmarks and Test Tools
Dell HPC NFS Storage Solution - High Availability Configurations
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C.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.
mdtest is launched with mpirun. For these tests, OpenMPI from Mellanox OFED 1.5.1 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
As with the IOzone random access patterns, the following procedure was followed to minimize cache
effects during the metadata testing:
Unmount NFS share on clients.
Stop the cluster service on the server. This umounts the XFS file system on the server.
Start the cluster service on the server.
Mount NFS Share on clients.
Metadata file and directory creation:
# mpirun -np 32 --nolocal --hostfile ./hosts /nfs/share/mdtest -d
/nfs/share/filedir -i 6 -b 320 -z 1 -L -I 3000 -y -u -t -C
Metadata file and directory stat
# mpirun -np 32 --nolocal --hostfile ./hosts /nfs/share/mdtest -d
/nfs/share/filedir -i 6 -b 320 -z 1 -L -I 3000 -y -u -t -R -T
Metadata file and directory removal:
# mpirun -np 32 --nolocal --hostfile ./hosts /nfs/share/mdtest -d
/nfs/share/filedir -i 6 -b 320 -z 1 -L -I 3000 -y -u -t -r