However, as far as I see in 15.2.8-0ubuntu0.20.04.1/focal there is no place in /var/lib/dpkg/info/ceph-osd.postinst activating the sysctl file so it requires a reboot basically or manual intervention is required to apply the value in the package. I think that's why fs.aio-max-nr wasn't applied in the first place.
Adding Ubuntu Ceph packaging task here.
30-ceph-osd.conf file is owned by ceph-osd package as follows.
$ dpkg -S /etc/sysctl. d/30-ceph- osd.conf d/30-ceph- osd.conf
ceph-osd: /etc/sysctl.
However, as far as I see in 15.2.8- 0ubuntu0. 20.04.1/ focal there is no place in /var/lib/ dpkg/info/ ceph-osd. postinst activating the sysctl file so it requires a reboot basically or manual intervention is required to apply the value in the package. I think that's why fs.aio-max-nr wasn't applied in the first place.