Product Information
saptune – a deep dive
Saptune version 2 has been released a few days ago and as promised, I start my technical blog post series. Over the next few weeks I will add the links to the articles here.
Let me answer the most important questions you might have first:
What shall I do? Update now or wait?
To answer this, we need to know how saptune version 1 is configured.
# saptune note list
All notes (+ denotes manually enabled notes, * denotes notes enabled by solutions):
1275776 Linux: Preparing SLES for SAP environments
1557506 Linux paging improvements
1984787 SUSE LINUX Enterprise Server 12: Installation notes
...
If no notes are applied, saptune will switch to version 2 after the package update.
In case you have reverted the notes only temporarily and you want to continue to use version 1 for now, please enable at least one note during the package update to prevent the switch.
# saptune note list
All notes (+ denotes manually enabled notes, * denotes notes enabled by solutions):
* 1275776 Linux: Preparing SLES for SAP environments
* 1557506 Linux paging improvements
* 1984787 SUSE LINUX Enterprise Server 12: Installation notes
...
If notes are enabled, saptune will keep running as version 1 after the package update, so the update will not change the behaviour of your system. This was a very important requirement!
But this also means, that you have to migrate to version 2 manually. This is described in detail in the man page saptune-migrate(5) and will also be a topic in the blog series.
As an alternative, you can revert all notes or solutions before the update of the package to get version 2 and re-apply them afterwards.
If you choose this, please make yourself familiar with the changes of saptune version 2 first! The solutions and SAP notes have changed. The tuning – even with the same notes or solution – will be different most certainly! Also do not forget manually changes, you might have done!
I hope this helps you to decide, when to update the saptune package.
More about saptune in the next article.
Further documentation:
- https://documentation.suse.com/sles-sap/12-SP4/html/SLES4SAP-guide/cha-s4s-tune.html#sec-saptune
- https://documentation.suse.com/sles-sap/15-SP1/html/SLES4SAP-guide/cha-s4s-tune.html#sec-saptune
- SAP Note 1275776
- man pages of the saptune package
Hello Soeren,
if i migrate saptune version 1 up to version 2 and revert the application (described in man saptune-migrate) what kind of influences have this on running sap application server or hana databases.
The question is have i to stop sap or hana before i do the migration, or have this migration process which last 10 minutes no influences on the running systems.
Kind regards
Juergen
Hi Jürgen,
During such a migration the system is not tuned. Since some of the tuning addresses problems with the OS defaults and SAP HANA on high load, it is better to shut it down.
On the other hand you will do such a migration in a maintenance window, where the SAP HANA is dormant. The risks are low that something happens.
Although updates and upgrades can introduce new settings which might require a reboot or an application restart (The limits come to my mind).
In short: To be on the safe side it would be better to shut the SAP application down except you know exactly what you are doing an can judge the impacts of the changing OS parameters during the migration.
Let me add, that during a normal saptune update the tuning will not get interrupted, but you have to restart saptune to apply the (possible!) changes in the tuning introduced by that update. In such a restart case you have an untuned system for a few seconds, but again you will not do such actions during production time.
An exception is the update from saptune 2 to 3 because we get rid of 'tuned'. It was unavoidable to stop and restart the tuning during the package update.