Pacman hooks to keep kernel modules

README.md

These Pacman hooks can be used to keep old kernel modules active without rebooting. This can work around issues like new USB devices and Docker images not working properly after a kernel upgrade, but before a reboot.

Add the files to /etc/pacman.d/hooks to enable the functionality. It works by making a backup of your current kernel's /lib/modules/... directory before the new kernel is installed, and then moving it back to the /lib/modules directory after the installation completes, working around the default behavior of deleting the old modules.

You can manually clean up the files after a reboot if you're concerned about the disk space used.

linux-modules-post.hook

[Trigger]
Operation = Upgrade
Type = Package
Target = linux

[Action]
Description = Restore Linux kernel modules
When = PostTransaction
Depends = coreutils
Depends = rsync
Exec = /bin/sh -xc 'KVER="${KVER:-$(uname -r)}"; if test -e "/lib/modules/backup/${KVER}"; then rsync -AHXal --ignore-existing "/lib/modules/backup/${KVER}" /lib/modules/; fi; rm -rf /lib/modules/backup'

linux-modules-pre.hook

[Trigger]
Operation = Upgrade
Type = Package
Target = linux

[Action]
Description = Save Linux kernel modules
When = PreTransaction
Depends = rsync
Exec = /bin/sh -c 'KVER="${KVER:-$(uname -r)}"; if test -e "/lib/modules/${KVER}"; then rsync -AHXal --delete-after "/lib/modules/${KVER}" /lib/modules/backup/; fi'

I actually recommend using saber-nyan's kernel-modules-hook package from the AUR to solve this.