/dev/null must always be the correct character device; if it's a file then it's perfectly reasonable for things to fail.
Now, it shouldn't have changed to a file - it's possible you hit bug 387189 is there a /dev/null.1 which is the original character device? Dave ** Changed in: openssh (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to openssh in ubuntu. https://bugs.launchpad.net/bugs/717837 Title: sshd fails to restart after /dev/null is changed to regular file -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs