Identifying Memory Performance Issues (BUI)
Use the following procedure to identify and remedy memory hardware bottlenecks on the
appliance. Based on the results of the analytic dataset, suggested corrective actions are
provided to increase memory performance by installing more DRAM.
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Create a worksheet as described in Creating a Worksheet (BUI).
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Click the add icon
next to Add statistic.
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Go to CACHE > ARC accesses > Broken down by hit/miss.
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Wait at least 10 minutes.
Note -
Ten minutes is a general guideline. The amount of time may be adjusted if you have
shorter-duration workloads that are memory intensive.
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Examine the graph.
You may want to install more DRAM when all of the conditions in the following table
are present.
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ARC access hits for data or metadata are at least 75-97% compared to
misses
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The ARC is providing a benefit by storing data or metadata that the
applications need.
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ARC access hits for data or metadata are significantly greater than prefetch
hits
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The majority of the ARC accesses are for real applications rather than just
the prefetch mechanism.
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ARC is accessed at least 10,000 times per second
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The appliance is hitting DRAM, which is not the typical utilization of an
idle system.
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Nearly all memory is consumed by the ARC, leaving very little unused
memory
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The appliance is utilizing all of the DRAM possible for the ARC, not just
serving a hot workload out of a small subset of the DRAM that is already
present.
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