atom's suggestion to stop all disk operations was the key to fixing this. I had a ddrescue operation going on in the background that I stopped after reading this thread, and BAM it started moving up from 37% and eventually finished.
Basically, this issue affected me as well on Ubuntu 14.04 x64, when trying to update my nvidia drivers from graphics-drivers ppa. I did 'sudo apt install nvidia-384' and it was stuck at 37% saying 'update- initramfs: Generating /boot/initrd.img-3.13.0-144-generic' for 20+ minutes. At that point I went to /boot/ and saw that a 'initrd.img-3.13.0-144-generic.new' was sitting around with a 0 file size since 20 minutes ago. Something was stuck but I didn't know until reading this issue. -- 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 email@example.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs