Problem is still occurring. My server has been sitting in a half-upgraded unrebooted state since I filed this Bug. I've been killing the hung mdadm.postint script occasionally and re-running apt-get dist-upgrade. Currently, the processes that are hanging are: root@kami:~# ps auxww | grep dpkg root 17854 0.0 0.2 17764 5308 pts/3 Ss+ 11:10 0:00 /usr/bin/dpkg --status-fd 47 --configure mdadm:amd64 libitm1:amd64 libgomp1:amd64 libasan0:amd64 libatomic1:amd64 libtsan0:amd64 libquadmath0:amd64 cpp-4.8:amd64 libgcc-4.8-dev:amd64 gcc-4.8:amd64 libstdc++-4.8-dev:amd64 g++-4.8:amd64 libpython3.3-minimal:amd64 python3.3-minimal:amd64 libpython3.3-stdlib:amd64 python3.3:amd64 bash-completion:all libsystemd-daemon0:amd64 systemd-shim:amd64 systemd-services:amd64 libpam-systemd:amd64 libpci3:amd64 pciutils:amd64 libsystemd-login0:amd64 imagemagick-common:all libasound2-data:all libasound2:amd64 libcups2:amd64 libcupsfilters1:amd64 libcupsimage2:amd64 libgdk-pixbuf2.0-common:all libgdk-pixbuf2.0-0:amd64 libmagickcore5:amd64 libmagickwand5:amd64 libmagickcore5-extra:amd64 libpolkit-agent-1-0:amd64 libpolkit-backend-1-0:amd64 libpython3.4-minimal:amd64 python3.4-minimal:amd64 libpython3.4-stdlib:amd64 python3.4:amd64 librados2:amd64 librbd1:amd64 libsnmp-base:all libsnmp30:amd64 php5-common:amd64 php5-mysql:amd64 php5-cli:amd64 php5-readline:amd64 libapache2-mod-php5:amd64 php5-gd:amd64 php5-curl:amd64 qemu-system-common:amd64 dh-python:all locales:all upstart:amd64 libisc95:amd64 libdns100:amd64 libisccc90:amd64 libisccfg90:amd64 libbind9-90:amd64 liblwres90:amd64 bind9utils:amd64 bind9:amd64 bind9-host:amd64 dnsutils:amd64 geoip-database:all libglib2.0-data:all lshw:amd64 memtest86+:amd64 openssh-client:amd64 openssh-sftp-server:amd64 openssh-server:amd64 python3-problem-report:all python3-apport:all python3-distupgrade:all ubuntu-release-upgrader-core:all python3-gi:amd64 shared-mime-info:amd64 ufw:all uuid-runtime:amd64 grub-common:amd64 apport:all apport-symptoms:all libdpkg-perl:all dpkg-dev:all imagemagick:amd64 libjs-sphinxdoc:all qemu-keymaps:all qemu-system-x86:amd64 qemu-kvm:amd64 libvirt0:amd64 libvirt-bin:amd64 linux-libc-dev:amd64 php5:all policykit-1:amd64 vim-puppet:all puppet-common:all puppet:all python-cinderclient:all python-gi:amd64 python-libvirt:amd64 python-lxml:amd64 python-novaclient:all python-secretstorage:all unattended-upgrades:all python-software-properties:all python-webtest:all qemu-utils:amd64 snmp:amd64 snmpd:amd64 ssh:all wpasupplicant:amd64 hardening-includes:all python-nova:all nova-common:all python-keystone:all python-swiftclient:all python-vm-builder:all ubuntu-vm-builder:all util-linux-locales:all root 17855 0.1 0.7 63112 15192 pts/3 S+ 11:10 0:00 /usr/bin/perl -w /usr/share/debconf/frontend /var/lib/dpkg/info/mdadm.postinst configure 3.2.5-5ubuntu2 root 17867 0.0 0.0 4444 684 pts/3 S+ 11:10 0:00 /bin/sh /var/lib/dpkg/info/mdadm.postinst configure 3.2.5-5ubuntu2 root 18331 0.0 0.0 10464 880 pts/1 S+ 11:14 0:00 grep dpkg And the culprit appears to be update-grub: root@kami:~# ps auxww | grep grub root 17854 0.0 0.2 17764 5308 pts/3 Ss+ 11:10 0:00 /usr/bin/dpkg --status-fd 47 --configure mdadm:amd64 libitm1:amd64 libgomp1:amd64 libasan0:amd64 libatomic1:amd64 libtsan0:amd64 libquadmath0:amd64 cpp-4.8:amd64 libgcc-4.8-dev:amd64 gcc-4.8:amd64 libstdc++-4.8-dev:amd64 g++-4.8:amd64 libpython3.3-minimal:amd64 python3.3-minimal:amd64 libpython3.3-stdlib:amd64 python3.3:amd64 bash-completion:all libsystemd-daemon0:amd64 systemd-shim:amd64 systemd-services:amd64 libpam-systemd:amd64 libpci3:amd64 pciutils:amd64 libsystemd-login0:amd64 imagemagick-common:all libasound2-data:all libasound2:amd64 libcups2:amd64 libcupsfilters1:amd64 libcupsimage2:amd64 libgdk-pixbuf2.0-common:all libgdk-pixbuf2.0-0:amd64 libmagickcore5:amd64 libmagickwand5:amd64 libmagickcore5-extra:amd64 libpolkit-agent-1-0:amd64 libpolkit-backend-1-0:amd64 libpython3.4-minimal:amd64 python3.4-minimal:amd64 libpython3.4-stdlib:amd64 python3.4:amd64 librados2:amd64 librbd1:amd64 libsnmp-base:all libsnmp30:amd64 php5-common:amd64 php5-mysql:amd64 php5-cli:amd64 php5-readline:amd64 libapache2-mod-php5:amd64 php5-gd:amd64 php5-curl:amd64 qemu-system-common:amd64 dh-python:all locales:all upstart:amd64 libisc95:amd64 libdns100:amd64 libisccc90:amd64 libisccfg90:amd64 libbind9-90:amd64 liblwres90:amd64 bind9utils:amd64 bind9:amd64 bind9-host:amd64 dnsutils:amd64 geoip-database:all libglib2.0-data:all lshw:amd64 memtest86+:amd64 openssh-client:amd64 openssh-sftp-server:amd64 openssh-server:amd64 python3-problem-report:all python3-apport:all python3-distupgrade:all ubuntu-release-upgrader-core:all python3-gi:amd64 shared-mime-info:amd64 ufw:all uuid-runtime:amd64 grub-common:amd64 apport:all apport-symptoms:all libdpkg-perl:all dpkg-dev:all imagemagick:amd64 libjs-sphinxdoc:all qemu-keymaps:all qemu-system-x86:amd64 qemu-kvm:amd64 libvirt0:amd64 libvirt-bin:amd64 linux-libc-dev:amd64 php5:all policykit-1:amd64 vim-puppet:all puppet-common:all puppet:all python-cinderclient:all python-gi:amd64 python-libvirt:amd64 python-lxml:amd64 python-novaclient:all python-secretstorage:all unattended-upgrades:all python-software-properties:all python-webtest:all qemu-utils:amd64 snmp:amd64 snmpd:amd64 ssh:all wpasupplicant:amd64 hardening-includes:all python-nova:all nova-common:all python-keystone:all python-swiftclient:all python-vm-builder:all ubuntu-vm-builder:all util-linux-locales:all root 17878 0.0 0.1 11736 2156 pts/3 S+ 11:10 0:00 /bin/bash /usr/sbin/update-grub root 18341 0.0 0.0 10464 880 pts/1 S+ 11:16 0:00 grep grub But when I kill mdadm.postint and run update-grub by hand it works fine...but loops through the kernels twice. root@kami:~# kill 17855 17867 root@kami:~# update-grub Searching for GRUB installation directory ... found: /boot/grub Searching for default file ... found: /boot/grub/default Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst Searching for splash image ... none found, skipping ... Found kernel: /boot/vmlinuz-3.13.0-17-generic Found kernel: /boot/vmlinuz-3.11.0-15-generic Found kernel: /boot/memtest86+.bin Found kernel: /boot/vmlinuz-3.13.0-17-generic Found kernel: /boot/vmlinuz-3.11.0-15-generic Found kernel: /boot/memtest86+.bin Updating /boot/grub/menu.lst ... done If it run it again, it only loops through once: root@kami:~# update-grub Searching for GRUB installation directory ... found: /boot/grub Searching for default file ... found: /boot/grub/default Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst Searching for splash image ... none found, skipping ... Found kernel: /boot/vmlinuz-3.13.0-17-generic Found kernel: /boot/vmlinuz-3.11.0-15-generic Found kernel: /boot/memtest86+.bin Updating /boot/grub/menu.lst ... done I finally bit the bullet and tried to reboot (from remote) after getting a clean apt-get dist-upgrade run and running update-grub manually. The system is pingable but I can no longer login; I'll have to check console when I get home.