Package: multipath-tools Version: 0.8.5-2 Updating the first the first servers which boot from FC SAN via multipath (dual FC emulex HBAs, two FC switches etc.) from buster to bullseye, I got a server without a configured network.
Investigating the issue I stumbled accross an issue raised by udevadm complaining about being called by multipathd.service which seems to be the reason why my network didn't came up: systemctl status systemd-udev-settle.service - systemd-udev-settle.service - Wait for udev To Complete Device Initialization Loaded: loaded (/lib/systemd/system/systemd-udev-settle.service; static) Active: failed (Result: exit-code) since Mon 2022-03-14 16:01:45 CET; 11min ago Docs: man:systemd-udev-settle.service(8) Process: 919 ExecStart=udevadm settle (code=exited, status=1/FAILURE) Main PID: 919 (code=exited, status=1/FAILURE) CPU: 4.435s Mar 14 15:59:45 xen-3 systemd[1]: Starting Wait for udev To Complete Device Initialization... Mar 14 15:59:46 xen-3 udevadm[919]: systemd-udev-settle.service is deprecated. Please fix multipathd.service not to pull it in. Mar 14 16:01:45 xen-3 systemd[1]: systemd-udev-settle.service: Main process exited, code=exited, status=1/FAILURE Mar 14 16:01:45 xen-3 systemd[1]: systemd-udev-settle.service: Failed with result 'exit-code'. Mar 14 16:01:45 xen-3 systemd[1]: Failed to start Wait for udev To Complete Device Initialization. Mar 14 16:01:45 xen-3 systemd[1]: systemd-udev-settle.service: Consumed 4.435s CPU time. removing the dependency to systemd-udev-settle.service from /lib/systemd/system/multipathd.service seems to resolve this issue. At least my System boots (including networking) without issues. Otherwise ifupdown-pre.service got stuck, I think at calling 'udevadm settle' during boot. Later I was able to bring up my network interfaces without issues.