Here's our s390x configuration: https://pagure.io/fedora-kiwi-descriptions/blob/rawhide/f/teams/cloud/cloud.xml#_132-151

Looks like based on the docs, we are created a DASD system. Should we do something else?

Ping @osinside

my guess is that we should use SCSI instead of CDL for the targettype to be compatible with the F<=39 images

You want to send a pull request to make the change? You can also test to see if it fixes it by doing a local build (we don't have CI for s390x or ppc64le images since they aren't available in Zuul CI).

sure, I can give it a try. How the kiwi command line for a local run should look like?

I see your target blocksize is set to 4096 and your boot mode is CDL. This is a typical DASD layout and will not work on any 512byte block storage.

For use of an image in qemu or on a SCSI type storage don't set any blocksize or targettype. I think the integration test definition from here should help:

• https://github.com/OSInside/kiwi/blob/main/build-tests/s390/rawhide/test-image-disk/appliance.kiwi

See the difference between Virtual and Physical

The conversion of a DASD image into a qcow2 image produces garbage :-)

Hope this helps

sure, I can give it a try. How the kiwi command line for a local run should look like?

For building s390 I have access to the IBM self service. Not sure how you can access s390 machines. If you have one the build should be:

sudo dnf install kiwi kiwi-systemdeps
git clone https://pagure.io/fedora-kiwi-descriptions.git
cd fedora-kiwi-descriptions
sudo kiwi-ng --profile Cloud-Base-Generic \
    system build --description `pwd` --target-dir /tmp/myfedora

I'm not entirely sure about the correct profile selection, but Neal can help with that

There is also the kiwi-build script in the git

I see your target blocksize is set to 4096 and your boot mode is CDL. This is a typical DASD layout and will not work on any 512byte block storage.

For use of an image in qemu or on a SCSI type storage don't set any blocksize or targettype. I think the integration test definition from here should help:

• https://github.com/OSInside/kiwi/blob/main/build-tests/s390/rawhide/test-image-disk/appliance.kiwi

See the difference between Virtual and Physical

The conversion of a DASD image into a qcow2 image produces garbage :-)

Hope this helps

it confirms my suspicion, thanks :-) We want to target the "virtual" environment with the qcow2 image.

I am using sudo ./kiwi-build --output-dir=/var/tmp/work --image-type=oem --image-profile=Cloud-Base-Generic as shown in the descriptions repo, but it wasn't clear to me originally what the values for type and profile should be.

diff --git a/teams/cloud/cloud.xml b/teams/cloud/cloud.xml
index aa928dd..fac7b40 100644
--- a/teams/cloud/cloud.xml
+++ b/teams/cloud/cloud.xml
@@ -132,12 +132,12 @@
        <preferences profiles="Cloud-Base-Generic" arch="s390x">
                <type image="oem" format="qcow2"
                      filesystem="btrfs" btrfs_root_is_subvolume="true" btrfs_set_default_volume="false" fsmountoptions="compress=zstd:1"
-                     kernelcmdline="no_timer_check console=tty1 console=ttyS0,115200n8 dasd_mod.dasd=ipldev systemd.firstboot=off"
-                     devicepersistency="by-uuid" target_blocksize="4096"
+                     kernelcmdline="no_timer_check console=ttyS0 systemd.firstboot=off"
+                     devicepersistency="by-uuid"
                      bootpartition="true" bootpartsize="1000" bootfilesystem="ext4"
                      rootfs_label="fedora"
                      >
-                       <bootloader name="zipl" targettype="CDL" timeout="1"/>
+                       <bootloader name="zipl" timeout="1"/>
                        <size unit="G">5</size>
                        <systemdisk>
                                <volume name="@root=root"/>

gives me a btrfs based image, that's bootable and gets further than the F-40 image, but it fails with

...
[  OK  ] Reached target initrd-switch-root.target - Switch Root.
         Starting initrd-switch-root.service - Switch Root...
[FAILED] Failed to start initrd-switch-root.service - Switch Root.
See 'systemctl status initrd-switch-root.service' for details.

Maybe something btrfs related?

Looks like the root device did not appear. How do you boot the image ? I normally go with the following qemu call on a KVM enabled s390 zVM or LPAR (/dev/kvm should exist)

sudo qemu-system-s390x -m 4096 --nographic --enable-kvm -drive if=none,id=dr1,file=kiwi-test-image-disk.s390x-1.15.1.qcow2 -device virtio-blk,drive=dr1,bootindex=1

if it does not work, rebuild the image and set in the kernelcmdline rd.debug rd.shell rd.break=pre-mount This should drop you into the initrd and further debugging becomes possible

I am using virt-install on a LPAR, eg.
virt-install --name localcloud-41 --memory 4096 --noreboot --graphics none --os-variant detect=on,name=fedora-unknown --cloud-init user-data="/home/sharkcz/cloudinit-user-data.yaml" --disk=size=10,backing_store="/var/lib/libvirt/images/Fedora.s390x-Rawhide.qcow2" after copying the qcow2 image to the libvirt's store.

first step in https://pagure.io/fedora-kiwi-descriptions/pull-request/62

The rootfs not found issue sounds like rootflags=subvol=root missing on the kernel parameter line ...

and yes, it is that.

umount /sysroot
mount -o subvol=root /dev/vda2 /sysroot
exit

in the rescue shell made the boot continue correctly and present a login prompt at the end

I'm still debugging why the rootflags are missing...

I found the issue. There is one method in kiwi that was not properly moved into the bootloader_spec_base base class. This missing function caused the missing rootflags for the BLS bootloaders that we support in kiwi.

I will create a patch on the kiwi sode. Sorry for this one

https://github.com/OSInside/kiwi/pull/2562

I tested on my s390 machine with the fedora description

https://github.com/OSInside/kiwi/pull/2562

I tested on my s390 machine with the fedora description

awesome and successfully tested

yay, thanks for testing :)

Hi,

This error seems quite similar to the one I am currently facing. When I run the following command with the Fedora 40 s390x cloud image:
"""
qemu-system-s390x -M accel=kvm -m 2048 -smp 2 -hda Fedora-Cloud-Base-Generic.s390x-40-1.14.qcow2 -net nic -net user -nographic
"""

I receive the same error output as shown in the first message. Fedora 39 and 41 work fine. Do you have any insights on what could be causing this issue?

I think we released the broken F-40 image as the fix in kiwi has been implemented after the F-40 GA. Can you give https://kojipkgs.fedoraproject.org/compose/cloud/Fedora-Cloud-40-20250228.0/compose/Cloud/s390x/images/Fedora-Cloud-Base-Generic.s390x-40-20250228.0.qcow2 a try? It's an updated cloud image.

I tested the "kiwi" image, and it works perfectly. Do you have a timeframe for the next release?

I don't think I understand the question. Updated F-40 images are being released daily at https://kojipkgs.fedoraproject.org/compose/cloud/, the F-40 GA image won't be replaced, also F-40 is slowly reaching its end of life (May 28th 2025). F-41, which is working for you, was released end of October last year.