I too ran in to a problem after upgrading a luks full disk encrypted 12.04.5 system to 14.04.1. After successfully upgrading, upon reboot I was asked for the luks password for the root system. After entering the password, I see sever errors including "/sbin/cryptsetup not found".
After doing research I came across bug https://bugs.launchpad.net/ubuntu/+source/cryptsetup/+bug/1256730. After booting from a rescue cd, creating the file in comment #4 and updating the initrd, the cryptsetup could be found in the initrd. Another reboot and all was good. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1237556 Title: cryptsetup removed from initrd.img on upgrade to 13.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cryptsetup/+bug/1237556/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
