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Tune VxFlex OS for best performance
You can improve theVxFlex OS system performance in terms of IOPs, latency, and
bandwidth, by making environment-specific fine-tunings on the operating system,
network, and VxFlex OS components.
Note: Performance tuning is very case-specific. To prevent undesirable effects, it
is highly recommended to thoroughly test all changes. For further assistance,
contact
https://support.emc.com .
Performance tuning post-installation
This section describes steps to take after completing a successful installation to
enhance performance.
Upgrades
For any VxFlex OS upgrade from 2.x to 3.x, profile parameters are preserved during
the upgrade. If Fine Granularity is configured and the profile was compact, it changes
to high performance. For a clean 3.x install, high performance is the default. Users
should implement performance tunings by following the guidelines described in this
document.
Fine granularity layout performance considerations
Fine granularity layout enables 4KB granularity and compression.
The benefit of the more efficient FG layout (pools) that allow 4KB granularity plus
compression vs. 1MB of MG layout (pool) come at some performance cost. In most
cases (but not all) FG will be slower than MG. In FG layout, when compression is
enabled, Reads are slower than in cases where compression is disabled. There are
exceptions to these rules. For example Write Response Time is similar in FG and MG.
Another exception is using snaps. In FG the snaps have no impact on the performance
of applications and workloads running during the snap creation. In MG snaps might
have an impact on performance in some cases.
For this reason, in cases that are very sensitive to performance and do not require
snaps, MG would be a better choice. It would also be a good option for cases where
the data is uncompressible for example if it is already compressed or if the data is
encrypted by the application.
Tuning considerations
In version 3.x, high_performance profile is the default. Medium Granularity
configuration can be changed to compact which would require less memory and CPU
resources, however it may have some impact on the performance of the setup. With
Fine Granularity configuration, including a mixed Fine and Medium Granularity, only
high_performance profile is allowed.
The main difference between the high_performance (default) and compact profiles
are the amount of server resources (CPU and memory) that are consumed. A
high_performance profile (or configuration) will always consume more resources.
This document will describe commands using the VxFlex OS command line interface
(scli) to quickly and easily modify the desired performance profile.
VxFlex OS performance fine-tuning
112 Dell EMC VxFlex Ready Node AMS User Guide