Appendix B: Benchmarks And Tests; Iozone; B.1. Iozone - Dell PowerEdge EL Manual

Improving NFS Performance on HPC Clusters with Dell Fluid Cache for DAS

Appendix B: Benchmarks and tests

The benchmark was used to measure sequential read and write throughput (MiB/sec) as well as

iozone

random read and write I/O operations per second (IOPS).
The benchmark was used to test metadata operation performance.
mdtest

B.1. IOzone

You can download the
and installed the compute nodes.
The tests were run from 1-64 nodes in clustered mode. All tests were N-to-N, that is N clients
IOzone
would read or write N independent files.
Between tests, the following procedure was followed to minimize cache effects:
•
Unmount NFS share on clients.
•
Stop the NFS service and unmount the XFS file system on the server.
•
Mount XFS file system on the server and start the NFS service.
•
Mount NFS Share on clients.
In addition for the cold cache tests described in Section 3.4, the disk managed by Dell Fluid Cache for
DAS was disabled and the SSDs that are part of the cache pool were disabled after a write operation.
DFC was re-configured prior to the read tests thus ensuring that all reads were from a cold-cache.
The following table describes the IOzone command line arguments.
IOzone Argument
-i 0
-i 1
-i 2
-+n
-c
-t
-e
-r
-s
from http://www.iozone.org/. Version 3.4.08 was used for these tests
IOzone
Write test
Read test
Random Access test
No retest
Includes close in the timing calculations
Number of threads
Includes flush in the timing calculations
Records size
File size
Description
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