How to persistently change /sys/kernel Linux settings now with the tuned package removed in Amazon Linux 2023?

Question

With the tuned package now missing on current Amazon Linux, https://github.com/amazonlinux/amazon-linux-2023/issues/327:

Which cost-efficient simple alternative exists to persistently store Linux configurations for /sys/kernel over a reboot?

For our business needs we require to change /sys/kernel/mm/transparent_hugepage/shmem_enabled from the Amazon Linux 2023 default of "never" to "advise".

Previously on Amazon Linux 2 we could easily do that with the tuned package.

I see the sysfsutils package exists, but that's a different one than the identically named on Ubuntu where that package uses configuration files below /etc/sysfs.d for permanently modifying settings below /sys/kernel and the AL2023 version doesn't offer that functionality.

If you decide to change the shmem_enabled setting to advise as default, that would of course also help us and we wouldn't need to change the configuration anymore.

Answer

I'm now continuing with the solution as simple single-file system service as that works fine.
Using the following systemctl service parameters to get it set early enough before apps are started:

```
[Unit]
Requires=local-fs.target
Before=network.target
[Service]
Type=oneshot
RemainAfterExit=true
```

If anyone knows better ways to persistently easily configure Linux /sys settings please comment.

Answer

A workaround would be to create a new system service of type Type=oneshot with RemainAfterExit=true.

Answer

Use the `sysfsutils` package. This package allows modifying settings under `/sys/kernel` by creating configuration files under `/etc/sysfs.d`
 Settings in these configuration files will apply on each reboot.

Use a configuration management tool like Ansible to modify the `/sys/kernel` setting and store the configuration. On reboot, Ansible can be used to re-apply the configuration.

Modify the GRUB configuration file (`/etc/default/grub`) to pass the required kernel parameter on boot. For example, to change the 
`transparent_hugepage` setting, add `transparent_hugepage=never` to the `GRUB_CMDLINE_LINUX` variable. Then run `grub2-mkconfig -o /boot/grub2/grub.cfg` to generate the config file..

How to persistently change /sys/kernel Linux settings now with the tuned package removed in Amazon Linux 2023?

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