Comment # 6 on bug 1155792 from Andrei Borzenkov

(In reply to Yuan Ren from comment #5)
> The updated spec file is :
> https://build.opensuse.org/package/view_file/home:yuanren10/Corosync-2_4_5/
> corosync.spec?expand=1
> But the disappear situation still occurs.

Was corosync rebuilt after this change? Downloaded package still contains
unconditional "rm /etc/sysconfig/corosync". You should check whether this is
final uninstall or update before removing file.

Also

if [ ! -e %{_sysconfdir}/sysconfig/corosync ]; then
    %fillup_only -n corosync
fi

This is wrong. It means /etc/sysconfig/corosync will miss any changes in
updated package (i.e. any new parameter won't appear in
/etc/sysconfig/corosync).