[RFE] longhorn v2 engine support (modules)

[hwaastad]

Current situation

The longhorn v2 engine has uio_pci_generic and nvme-tcp as module dependencies. These modules are not available in Flatcar OS (3975.2.0)

Impact

Unable to use longhorn v2 engine which has a giant leap in performance.

Ideal future situation

These module an integrated part of flatcar OS

Implementation options

It should be possible to add modules as a sysext extension or by building modules and do something like this:
https://blog.thesparktree.com/customize-flatcar-kernel-part-3

Additional information

[ader1990]

Hello @hwaastad, we can check if the modules can be built and added to the base image and what is the size increase (we are a bit limited on how much bytes we can add to the initrd). Can you give more context on how did you install longhorn and whould be the outcome in case that the modules are installed vs are not installed?

I assume that the installation is in k8s context, and you are using a https://longhorn.io/docs/1.7.0/deploy/install/install-with-kubectl/#installing-longhorn?

Also, do you need the modules for both amd64 and arm64?

Thanks.

[hwaastad]

Hi,
yes this is k8s context.
Installed via helm.
I have already build the modules so this should work fine. I have yet not checked the increase in size.

Longhorn v1 data engine works OOB with flatcar.
Longhorn v2 data engine (1.7.0 ) has prerequisite modules vfio_pci (already exists), uio_pci_generic and nvme-tcp.
So v2 engine will not work without these modules.

My requirements are only amd64

/hw