well, here are process trees with hung plymouth :
1225 ? Ss 0:00 /bin/sh /etc/init.d/rc 2 1443 ? S 0:00 \_ /bin/sh -e /etc/rc2.d/S15bind9 start 1449 ? S 0:00 \_ plymouth --ping
1720 ? Sl 0:01 \_ aptitude safe-upgrade 1755 pts/2 Ss+ 0:00 \_ /usr/bin/dpkg --status-fd 42 --unpack --auto-deconfigure /var/cache/apt/archives/postfix_2.8.2-1ubuntu2.1_amd64.deb 1761 pts/2 S+ 0:00 \_ /bin/sh -e /var/lib/dpkg/info/postfix.prerm upgrade 2.8.2-1ubuntu2.1 1762 pts/2 S+ 0:00 \_ /bin/sh /usr/sbin/invoke-rc.d postfix stop 1778 pts/2 S+ 0:00 \_ /bin/sh -e /etc/init.d/postfix stop 1791 pts/2 S+ 0:00 \_ plymouth --ping
well, here are process trees with hung plymouth :
1225 ? Ss 0:00 /bin/sh /etc/init.d/rc 2
1443 ? S 0:00 \_ /bin/sh -e /etc/rc2.d/S15bind9 start
1449 ? S 0:00 \_ plymouth --ping
1720 ? Sl 0:01 \_ aptitude safe-upgrade apt/archives/ postfix_ 2.8.2-1ubuntu2. 1_amd64. deb dpkg/info/ postfix. prerm upgrade 2.8.2-1ubuntu2.1 invoke- rc.d postfix stop
1755 pts/2 Ss+ 0:00 \_ /usr/bin/dpkg --status-fd 42 --unpack --auto-deconfigure /var/cache/
1761 pts/2 S+ 0:00 \_ /bin/sh -e /var/lib/
1762 pts/2 S+ 0:00 \_ /bin/sh /usr/sbin/
1778 pts/2 S+ 0:00 \_ /bin/sh -e /etc/init.d/postfix stop
1791 pts/2 S+ 0:00 \_ plymouth --ping