18 Tuning SUSE Linux Enterprise for SAP #

With sapconf 5.0.2 and up, the check tool sapconf_check is available, which verifies the correct setup of sapconf. For example:

# sapconf_check
This is sapconf_check v1.0.
It verifies if sapconf is set up correctly and will give advice to do so.
Please keep in mind:
{{ - This tool does not check, if the tuning itself works correctly.}}
{{ - Follow the hints from top to down to minimize side effects.}}
Checking sapconf
================
[ OK ] sapconf package has version 5.0.2
[ OK ] saptune.service is inactive
[ OK ] saptune.service is disabled
[WARN] tuned.service is enabled/active with profile 'virtual-guest -> Sapconf does not require tuned! Run 'systemctl stop tuned.service', if not needed otherwise.
[FAIL] sapconf.service is inactive -> Run 'systemctl start sapconf.service' to activate the tuning now.
[FAIL] sapconf.service is disabled -> Run 'systemctl enable sapconf.service' to activate sapconf at boot.1 warning(s) have been found.
2 error(s) have been found.
Sapconf will not work properly!

If sapconf_check finds problems, it gives hints on how to resolve the issue. The tool does not verify whether the system has been tuned correctly. It only checks that sapconf is set up correctly and has been started.

After the installation of sapconf, the sapconf service is enabled.

You can inspect or change the status of sapconf as described in the following:

Tip: Additional services that sapconf relies on

Besides the sapconf service, it also relies on the following two services:

• sysstat which collects data on system activity.

• uuidd which generates time-based UUIDs that are guaranteed to be unique even in settings where many processor cores are involved. This is necessary for SAP applications.

Generally, the default configuration of sapconf already uses the parameter values recommended by SAP. However, if you have special needs, you can configure the tool to better suit those.

All parameters of sapconf can be found in the file /etc/sysconfig/sapconf. The file can be edited directly. All parameters in this file are explained by comments and references to SAP Notes, which can be viewed at https://launchpad.support.sap.com/.

When sapconf is updated, all customized parameters from this file are preserved as much as possible. However, sometimes parameters cannot be transferred cleanly to the new configuration file. Therefore, after updating it is advisable to check the difference between the previous custom configuration, which during the update is moved to /etc/sysconfig/sapconf.rpmsave, and the new version at /etc/sysconfig/sapconf.

Log messages related to this file are written to /var/log/sapconf.log.

When editing either of these files, you can find that certain values are commented by a # character at the beginning of the line. This means that while the parameter is relevant for tuning, there is no suitable default for it.

Conversely, you can add # characters to the beginning of the line to comment specific parameters. However, you should avoid this practice, as it can lead to sapconf not properly applying the profile.

To apply the edited configuration, restart sapconf:

# systemctl restart sapconf

Confirming that a certain parameter value was applied correctly works differently for different parameters. Hence, the following serves as an example only:

To remove sapconf from a system, uninstall its package with:

# zypper rm sapconf

When doing this, dependencies of sapconf remain installed. However, the service sysstat goes into a disabled state. If it is still relevant to you, make sure to enable it again.

The following man pages provide additional information about sapconf:

Also see the blog series detailing the updated version of sapconf at https://www.suse.com/c/a-new-sapconf-is-available/.

With version 5, sapconf does not rely on tuned anymore. This means both tools can be used independently. sapconf prints a warning in its log if the tuned service is started.

Important: Using tuned and sapconf together

If you are going to use tuned and sapconf simultaneously, ensure that both tools do not configure the same system parameters.