SSH connection refused after upgrading
SSH Server stops working after reboot, caused by missing /var/run/sshd
"'void' type not allowed here" error (Java) How does Linux kernel compare to microkernel architectures? I read once that one advantage of a microkernel architecture is that you can stop/start essential services like networking and filesystems, without needing to restart the whole system. But considering that Linux kernel nowadays (was it always the case?) offers the option to use modules to achieve the same effect, what are the (remaining) advantages of a microkernel? Are shell scripts sensitive to encoding and line endings? What does "--" (double-dash) mean? I have seen -- used in the compgen command.  For example:  compgen -W "foo bar baz" -- b   What is the meaning of the -- in there? There are lots of questions tagged  that don't have a  response.  How do we interpret this? Is it because they are declined by default? We just have to wait for a response (the team is very busy)? Is Jeff the only one that reviews this questions?  I suppose the ones that have negative votes may (or may not) be declined by default, but there are quite a few with some to a lot upvotes that should have an official answer. How to lazy load images in ListView in Android I'm trying to display models that have shading drawn or baked directly on the textures, but I can't figure out how to disable Blender's default scene lighting. If there are no lights in the scene, everything is black, but I want to see the textured objects fully bright. How do I disable the lighting?  NOTE: Just before posting this, I found the "Shadeless" material property, which does more or less what I want. However, is there a way to globally toggle the default lighting? Negative Mass and gravitation How do I check if an object has a specific property in JavaScript?  Consider:  x = {'key': 1}; if ( x.hasOwnProperty('key') ) {     //Do this }   Is that the best way to do it? How to install Python 3.6? Let $X$ be a transitive $G$-set. ($G$ acts on  $X$ transitively.) If $X$ is finite and has at least two elements, show that there is some element $g$ $\in$ G which does not have any fixed points; that is, such that $g$$($$x$$)$ $\ne$ $x$ for all $x$ $\in$ $X$  I am trying to use contradiction, but it is not very clear to me why this is true. In the first half of Tenet, there is a scene where The Protagonist and Neil break into Freeport and find a glass wall with bullet holes (could only find a good photo with Christopher Nolan in it):  In the next scene, we find out that these bullet holes were caused by an inverted armed man entering the room (exiting the room from their perspective) and reverse-shooting the glass, which removes the bullet holes from the future-facing perspective. This all makes sense, but raises a question: how long were the bullet holes there in the first place? Were they in place as soon as the glass was installed, possibly years ago? Or even back when the glass was manufactured? How does time work in The Matrix? How to create a new object instance from a Type One may not always know the Type of an object at compile-time, but may need to create an instance of the Type.    How do you get a new object instance from a Type? Understanding UNIX permissions and file types How can I add a PPA from a previous release? Why does volatile exist? What does the volatile keyword do? In C++ what problem does it solve?  In my case, I have never knowingly needed it. computing the orbits for a group action Let $G$ be the Galois group of a field with nine elements over its subfield with three elements. Then the number of orbits for the action of $G$ on the fields with nine elements is   3 5 6 9   I have no idea how to compute the numbers of orbits for a group action. Anyone please help me. Thanks. In The Last Jedi:     The Resistance fleet is tracked through hyperspace by the First Order after they make their jump away from their old base.   As soon as the FO ships appear, the Resistance immediately come to the (correct) conclusion as to the tech that was used.  Why would they assume the use of this tech, that they have never encountered before, as opposed to the more common technique of     tracking a ship through the use of a homing beacon. Prove that $a^3+b^3+c^3 \geq a^2b+b^2c+c^2a$ Let $a,b,c$ be positive real numbers. Prove that $a^3+b^3+c^3\geq a^2b+b^2c+c^2a$.   My (strange) proof:  $$ \begin{align*} a^3+b^3+c^3 &amp;\geq a^2b+b^2c+c^2a\\ \sum\limits_{a,b,c} a^3 &amp;\geq \sum\limits_{a,b,c} a^2b\\ \sum\limits_{a,b,c} a^2 &amp;\geq \sum\limits_{a,b,c} ab\\ a^2+b^2+c^2 &amp;\geq ab+bc+ca\\ 2a^2+2b^2+2c^2-2ab-2bc-2ca &amp;\geq 0\\ \left( a-b \right)^2 + \left( b-c \right)^2 + \left( c-a \right)^2 &amp;\geq 0 \end{align*} $$  Which is obviously true.    However, this is not a valid proof, is it? Because I could just as well have divided by $a^2$ rather than $a$:  $$ \begin{align*} \sum\limits_{a,b,c} a^3 &amp;\geq \sum\limits_{a,b,c} a^2b\\ \sum\limits_{a,b,c} a &amp;\geq \sum\limits_{a,b,c} b\\ a+b+c &amp;\geq a+b+c \end{align*} $$  Which is true, but it would imply that equality always holds, which is obviously false. So why can't I just divide in a cycling sum?  Edit: Please don't help me with the original inequality, I'll figure it out.