udev's kmod builtin dlopens libkmod, and dracut installs it from an
inst_libdir_file line in a module-setup.sh rather than by following
NEEDED. Which module carries that line moved: the dracut on SLE 16
media declares it only in 00systemd, which the diskless module set
never loads, so the image came up with no libkmod, udev autoloaded
nothing, and the guest reached the network scan with only loopback.
Leap's newer dracut also declares it in 95udev-rules, which base
depends on, which is why Leap was unaffected.
OpenSSH 10 splits each connection into sshd-session and that into
sshd-auth, so the initramfs sshd on 2222 could not serve a single
session. el10 added sshd-session for the same reason.
SLES 16 ships no ISC dhclient and nothing provides dhcp-client, so the
image could not be built from SLES media at all. Leap carries dhcpcd
too, so one client covers both. el10 made the same move when RHEL
dropped dhclient.
SuseHandler refused anything but 15.x. What 16 needed beyond widening it:
- its repo urls are written in terms of ${releasever}, which zypper
resolves from the target root's os-release, a file that does not exist
yet when the first packages go in
- its repos name a zypper service backed by a package-provided directory
the target root does not have, so zypper discarded every one of them
as an orphan
- there is no mkinitrd to work out which kernel to build for, and bare
dracut would build for the build host's running kernel
- the efi payloads moved out of /usr/lib64/efi, arping out of /usr/sbin,
nsswitch.conf and protocols under /usr/etc, and the presets enable
sshd already
- the module list predated virtio, so an image built for a KVM guest had
no network at all, and dm-crypt could not allocate a transform for the
encrypted image without the aes-xts modules
- urlmount still links libpthread, an empty stub since glibc 2.34 that
nothing else in the initramfs pulls in