I have also reinstalled all these packages with the command "(find /etc/initramfs-tools -type f; find /usr/share/initramfs-tools -type f) | xargs dpkg -S | awk '{print substr($1, 0, length($1))}' | xargs sudo apt-get install --reinstall -y; sudo update-initramfs -u; sudo update-grub" to go sure that the files in /etc/initramfs-tools and /usr/share/initramfs-tools are unmodified. But after rebooting the system and going into the grub menu I'm still seeing the entry "single".
I have now made a look which files in /etc/initramfs- tools and /usr/share/ initramfs- tools belongs to which package. Here is the result:
sworddragon@ ubuntu: ~$ (find /etc/initramfs- tools -type f; find /usr/share/ initramfs- tools -type f) | xargs dpkg -S tools/initramfs .conf tools/modules tools/conf. d/resume tools/update- initramfs. conf initramfs- tools/conf- hooks.d/ cryptsetup initramfs- tools/hooks/ mountall initramfs- tools/hooks/ kmod initramfs- tools/hooks/ cryptkeyctl initramfs- tools/hooks/ cryptgnupg initramfs- tools/hooks/ cryptroot initramfs- tools/hooks/ plymouth configuration: /usr/share/ initramfs- tools/hooks/ console_ setup initramfs- tools/hooks/ framebuffer initramfs- tools/hooks/ cryptpassdev initramfs- tools/hooks/ udev initramfs- tools/hooks/ cryptopenct initramfs- tools/hooks/ fixrtc initramfs- tools/hooks/ thermal initramfs- tools/hooks/ cryptopensc initramfs- tools/hooks/ compcache initramfs- tools/hooks/ kbd initramfs- tools/hooks/ busybox initramfs- tools/hooks/ dmsetup initramfs- tools/hooks/ klibc initramfs- tools/hook- functions initramfs- tools/event- driven/ upstart- jobs/mountall. conf initramfs- tools/modules initramfs- tools/scripts/ nfs initramfs- tools/scripts/ local initramfs- tools/scripts/ local-top/ cryptroot initramfs- tools/scripts/ local-top/ cryptopensc initramfs- tools/scripts/ local-bottom/ cryptopensc initramfs- tools/scripts/ init-bottom/ plymouth initramfs- tools/scripts/ init-bottom/ udev initramfs- tools/scripts/ functions initramfs- tools/scripts/ init-top/ plymouth initramfs- tools/scripts/ init-top/ keymap configuration: /usr/share/ initramfs- tools/scripts/ init-top/ console_ setup initramfs- tools/scripts/ init-top/ framebuffer initramfs- tools/scripts/ init-top/ udev initramfs- tools/scripts/ init-top/ blacklist initramfs- tools/scripts/ init-top/ all_generic_ ide initramfs- tools/scripts/ panic/plymouth initramfs- tools/scripts/ panic/keymap configuration: /usr/share/ initramfs- tools/scripts/ panic/console_ setup initramfs- tools/scripts/ local-premount/ resume initramfs- tools/scripts/ local-premount/ fixrtc initramfs- tools/init
initramfs-tools: /etc/initramfs-
dpkg-query: no path found matching pattern /etc/initramfs-
dpkg-query: no path found matching pattern /etc/initramfs-
initramfs-tools: /etc/initramfs-
cryptsetup: /usr/share/
mountall: /usr/share/
kmod: /usr/share/
cryptsetup: /usr/share/
cryptsetup: /usr/share/
cryptsetup: /usr/share/
plymouth: /usr/share/
keyboard-
initramfs-tools: /usr/share/
cryptsetup: /usr/share/
udev: /usr/share/
cryptsetup: /usr/share/
initramfs-tools: /usr/share/
initramfs-tools: /usr/share/
cryptsetup: /usr/share/
initramfs-tools: /usr/share/
kbd: /usr/share/
initramfs-tools: /usr/share/
dmsetup: /usr/share/
initramfs-tools: /usr/share/
initramfs-tools: /usr/share/
mountall: /usr/share/
initramfs-tools: /usr/share/
initramfs-tools: /usr/share/
initramfs-tools: /usr/share/
cryptsetup: /usr/share/
cryptsetup: /usr/share/
cryptsetup: /usr/share/
plymouth: /usr/share/
udev: /usr/share/
initramfs-tools: /usr/share/
plymouth: /usr/share/
initramfs-tools: /usr/share/
keyboard-
initramfs-tools: /usr/share/
udev: /usr/share/
initramfs-tools: /usr/share/
initramfs-tools: /usr/share/
plymouth: /usr/share/
initramfs-tools: /usr/share/
keyboard-
initramfs-tools: /usr/share/
initramfs-tools: /usr/share/
initramfs-tools: /usr/share/
I have also reinstalled all these packages with the command "(find /etc/initramfs- tools -type f; find /usr/share/ initramfs- tools -type f) | xargs dpkg -S | awk '{print substr($1, 0, length($1))}' | xargs sudo apt-get install --reinstall -y; sudo update-initramfs -u; sudo update-grub" to go sure that the files in /etc/initramfs- tools and /usr/share/ initramfs- tools are unmodified. But after rebooting the system and going into the grub menu I'm still seeing the entry "single".