This problem also still exists with much newer kernels, for me with 4.15.0-12 on Ubuntu 18.04 (alpha)
------------------------------------ diff -uN /var/lib/dpkg/info/initramfs-tools.postinst~ /var/lib/dpkg/info/initramfs-tools.postinst --- /var/lib/dpkg/info/initramfs-tools.postinst~ 2018-02-20 22:34:46.000000000 +0100 +++ /var/lib/dpkg/info/initramfs-tools.postinst 2018-03-22 13:08:09.989213260 +0100 @@ -38,10 +38,10 @@ # Regenerate initramfs whenever we go to dpkg state `installed' if [ "x$1" != xtriggered ]; then # this activates the trigger, if triggers are working - update-initramfs -u + update-initramfs -u -v else # force it to actually happen - DPKG_MAINTSCRIPT_PACKAGE='' update-initramfs -u + DPKG_MAINTSCRIPT_PACKAGE='' update-initramfs -u -v fi # Automatically added by dh_installdeb/11.1.4ubuntu1 ----------------------------------------- diff -uN /usr/sbin/update-initramfs~ /usr/sbin/update-initramfs --- /usr/sbin/update-initramfs~ 2018-01-05 13:15:45.000000000 +0100 +++ /usr/sbin/update-initramfs 2018-03-22 13:11:34.440124524 +0100 @@ -158,7 +158,9 @@ mv -f "${initramfs}.new" "${initramfs}" set_sha1 # Guard against an unclean shutdown - sync + # The sync never returns and seems to deadlock for some reason + # so comment it out for the time beeing + #sync else mkinitramfs_return="$?" remove_initramfs_bak --------------------------------------------------------------- Also take sync out of commission in order to allow for a clean shutdown (important: re-enable after the reboot!). Also give the system enough time to sync all its buffers on its own before restarting. cd /bin mv sync sync.real cp ls sync This helped me before and now I have the deadlocked sync issue again. root@charion:~# ps auxwww | grep sync systemd+ 1949 0.0 0.0 146076 3364 ? Ssl 11:56 0:00 /lib/systemd/systemd-timesyncd root 19420 0.0 0.0 7796 780 pts/7 D+ 12:03 0:00 sync root 22919 0.0 0.0 14756 1120 pts/2 S+ 13:20 0:00 grep --color=auto sync So I'll try to restart and try to run the update-initramfs -u -v manually with these changes and then try to finish the apt-get upgrade -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1667512 Title: update-initramfs hangs on upgrade, dpkg unusable, unbootable system To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/initramfs-tools/+bug/1667512/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs