virtiofs support

[aaronk6]

I’m currently running Fedora CoreOS in a QEMU VM on my hypervisor, but would love to switch to Flatcar. I see that virtiofs isn’t included in Flatcar, which unfortunately is a dealbreaker for my use case.

Is virtiofs somewhere on your roadmap?

Thanks!

[skydiablo]

i'm running into the same problem, any suggestions?

[jepio]

How do you run Qemu?

Do ya'll mean adding the virtiofs module to the kernel? That shouldn't be an issue - open a PR.

[aaronk6]

Do ya'll mean adding the virtiofs module to the kernel? That shouldn't be an issue - open a PR.

@jepio Yes, thanks! That’s what I meant. I saw that in the Home Assistant OS project, they include further modules for virtiofs support (see home-assistant/operating-system@11c2eab), but I’ll start with adding only CONFIG_VIRTIO_FS and see if that’s sufficient for basic operation. I assume for Flatcar, it should be added as module (=m), correct?

I’ll open a PR once I have it working on my end.

@skydiablo If you want to try it as well, apply this change and create your custom build.

[skydiablo]

currently i'm trying to inject my cephfs into flatcar that docker is fully running on cephfs. for now, i am just mount cephfs (#342 (comment)) and force docker to use this mount:

DOCKER_DATA_ROOT="/mnt/cephfs_docker/docker_${FLATCAR_VM_ID}"
mkdir -p /run/flannel
echo "DOCKER_OPTS=\"--data-root=${DOCKER_DATA_ROOT}\"" > /run/flannel/flannel_docker_opts.env

but curently it failing with docker error:

dockerd[11095]: failed to start daemon: error while opening volume store metadata database (/mnt/cephfs_docker/docker_154/volumes/metadata.db): write /mnt/cephfs_docker/docker_154/volumes/metadata.db: operation not permitted

so, my next try is to use virtiofs, but as you know, a missing kernel module is my next problem :(

i want to try a mounted cephfs on host system to pipe it into the flatcar VM via virtiofs. but it think this will nothing change.

Currently, I'm a bit deterred from compiling my own Flatcar. I will now rely on binds in my Docker setup and use the current CephFS in Flatcar...

[jepio]

@aaronk6 if you open a PR with your change, I run the CI to publish a build for you 2 to test.

[aaronk6]

Oh, that’s great. Here’s the PR: flatcar/scripts#2825