White Papers

Dell HPC NFS Storage Solution - High Availability Configurations
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There are two methods to upgrade the solution:
1) Add capacity, same performance.
In this method user data is preserved during the upgrade. The final configuration provides 80TB
of capacity, but the performance is similar to a Medium configuration.
2) Add capacity, improved performance
In this second method all user data must be backed up. The upgrade will wipe out the existing
Medium configuration and create a Large configuration.
Performance of the two configurations is discussed in the section on Performance Benchmark
Results. Appendix B: Medium to Large Configuration Upgrade contains detailed instructions on the
two upgrade methods.
4. Evaluation
The architecture proposed in this white paper was evaluated in the Dell HPC lab. This section describes
the test methodology and the test bed used for verification. It also contains details on the functionality
tests. Performance results are presented in subsequent sections.
4.1. Methodology
The verification focused on three key areas – functionality, data correctness and performance.
Different component failures were simulated to test the failover of the cluster service. Apart from
hardware redundancies like dual power supplies, dual SAS links to the storage, dual PDUs described
in previous sections, the HA cluster is designed to automatically detect and tolerate several types
of component failures.
There are likely to be active data connections with clients reading and writing from the storage
during a failure scenario. Ensuring data correctness during a failover operation is a critical
requirement.
Performance testing of the solution was performed under a no failure case to understand the
maximum capability of the solution.