Tuning the operating system

Describes the operating system tuning procedure that is required for IBM Spectrum Scale cluster nodes.

Tune each node of the IBM Spectrum Scale cluster by following the procedure:

Note: Some tuning decisions require that you make choices that balance the benefits of optimal performance against the cost of potential additional energy usage. The best performance depends on the applications that are run. The configurations that are shown have demonstrated good results in IBM® lab testing. However, each configuration option you choose must be based on your own requirements.

Install the required packages to run the tuning commands. For example, on an RHEL system, run the following command to install the required software:
```
yum -y install tuned-utils tuned numactl powerpc-utils
```
Set throughput performance governor by running the following command:
```
tuned-adm profile throughput-performance
```
Set the CPU tuning by running the following commands:
```
cpupower idle-set -e 0
```
```
cpupower idle-set -D 1
```
You can run the following command to view the CPU settings:
```
cpupower idle-info
```
Note: You can reset the default values by using the following command:
```
cpupower idle-set -E
```
Set the value of Simultaneous multithreading (SMT) to 2 by running the following command:
```
ppc64_cpu –smt=2
```