Editing Basic Debian Installation (section)

== Proliant iLO Watchdog Timer ==
There appears to be an issue during boot with the watchdog timer that ends up in a deadlock waiting for a response from iLO.  It has happened now on most of the HP servers running Debian.  Thanks to a rather in-depth analysis and testing [[ https://www.claudiokuenzler.com/blog/1125/debian-11-bullseye-boot-freeze-kernel-panic-hp-proliant-dl380 | here ]], the problem seems to be the hpwdt module.  According to the article, it has been blacklisted in most other distros already.  The script below creates the blacklist entry and rebuilds the initramfs images:

 #!/bin/bash
 #
 # blacklist the HP iLO watchdog timer module (hpwdt) to avoid boot freezes under debian
 #
 echo "blacklist hpwdt" >> /etc/modprobe.d/blacklist-hp.conf
 update-initramfs -k all -u
 update-grub

This script is available on the config server:
 curl -s http://config/config/debian/fix-hpwdt.sh | bash -x