Comment 5 for bug 1713990

We do not recommend to use virt-install to create Ubuntu guest instances.

Instead, mirror and launch Ubuntu Cloud Image, with a cloud config drive to customize the instances.

You can find ready made Ubuntu Cloud Images for s390x at https://cloud-images.ubuntu.com/xenial/current/ note they are regularly refreshed to boot with latest kernel, SRU and security fixes.

You can customize the instances as needed using cloud-config stanzas http://cloudinit.readthedocs.io/en/latest/topics/examples.html

And one can trivially provide config-drive to the virtual machine using e.g. NoCloud http://cloudinit.readthedocs.io/en/latest/topics/datasources/nocloud.html

Have you considered using cloud-images to simply boot and initialize customized Xenial guests? It will complete provision much faster than d-i based methods.