Dell PowerEdge EL Manual

Also see for PowerEdge M420: Manual Command reference guide Owner's manual Administrator's guide Information update

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Dell PowerEdge EL Manual Manual pdf 16 page image

Improving NFS Performance on HPC Clusters with Dell Fluid Cache for DAS162.5.3. Dell Fluid Cache for DAS health and monitoringDFC provides a very simple command-line utility /opt/dell/fluidcache/bin/fldc that can beused for configuration and management. Alternately, the DFC configuration can be accomplished usingthe OMSA GUI. DFC is a component under the storage sub-section of the OMSA GUI./opt/dell/fluidcache/bin/fldcstat is a command-line utility that provides extensive statisticsof the cache hits on the system, disk IO, etc.Additional details are available in the DFC User’s Guide in [3].3. PerformanceThis section presents the results of performance tests conducted on the storage solution described inSection 2. Performance tests were run to evaluate the following common I/O patterns.• Large sequential reads and writes• Small random reads and writes• Metadata operationsThese tests were performed over the IP-over-InfiniBand (IPoIB) network as described in Section 2.3.The iozone and mdtest benchmarks were used for this study. Details of the benchmarks and testprocess are provided in Appendix B: Benchmarks and tests.Iozone was used for the sequential tests as well as the random tests. The I/O access patterns are N-to-N, i.e., each thread reads and writes to its own file. Iozone was executed in clustered mode and onethread was launched on each compute node. For the sequential tests, the performance metric usedwas throughput in terms of MiB/s. For random tests, I/O operations per second (IOPS) was the metric.The large sequential read and large sequential write tests were conducted using a request size of 1024KB. The total amount of data written was 256 GB. (Recall from Table 1 that the NFS server RAM is 128GB.) This is to ensure that the total I/O exceeds the NFS server memory since the goal is to test thedisk and storage solution performance.The small random tests were performed with 4 KB record sizes since the size corresponds to typicalrandom I/O workloads. Each client reads and writes a smaller 4 GB file for these tests.The metadata tests were performed with the mdtest utility and include file creates, stats, andremovals.While these benchmarks do not cover every I/O pattern, they help characterize the I/O performance ofthis storage solution.Each set of tests was run on a range of clients to test the scalability of the solution. The number ofsimultaneous clients involved in each test was varied from one to 64 clients. The client test bed isdescribed in Section 2.3.Tests were performed on three configurations:• Baseline - This is the pure NFS storage solution as described in Section 2.1.