Installing Ubuntu on existing RAID 1 with complete rebuild
Installing Ubuntu with Fake RAID 1
In Russian we have idiom/saying "To shoot out of cannon into sparrows" (literal translation) which is used to convey an idea of applying too drastic measures to small problems. I believe there should be some native-English equivalents to this saying. Can you share if there are any? Recently upgraded to Ubuntu 18.10, having two problems.  Easiest to explain: when I open "settings", go to "privacy", select "screen lock", I get the popup window with the screen lock settings, but everything is grayed out:   Second issue: If I step away from the machine for long enough (seems to be 5 minutes), the screen blanks. Hitting a key or moving the mouse wakes it up. But when it wakes up, the only things on the screen are the icon bar at the left and the top bar with status icons on the right end. The rest of the screen is blue, not my normal lock screen image. The screen isn't locked, it doesn't prompt for a password, it's just...blue.  I can move the mouse pointer around the screen, the icons react if I click on one, I can bring up the popup with volume/brightness controls on the top bar. But if the pointer is on the blue background, neither left nor right button clicks do anything.  Now, if I press ctrl-alt-F1 from there, I get a lock screen where I can enter my password. Then I get the blue screen back, but if I press ctrl-alt-F2 I get my normal screen (with running applications) back.  ctrl-alt-F2 without going through the lock screen first does nothing.  I'm not finding anything while searching that matches either of these sets of symptoms. Suggestions? Oxford Comma Conventions Preposition before noun phrases I have asked the same question in ELL stackexchange, but unfortunately haven't received enough answer/comment. The one answer I got is not satisfactory. So that's the reason I am asking it here again. .  I have seen in some cases prepositions are omitted before some noun phrases. And it's explained that those phrases are actually an adverb phrases. But I know a simple thing. If the head of the phrase is a noun, it's a noun phrase. If the head of the phrase is an adverb it is an adverb phrase. For example -   Look both ways before crossing the road. [both ways is a noun phrase, where the head is ways, but still there is no preposition.]  He approached me in a friendly way. [a friendly way is a noun phrase, where the head is way, but as expected unlike sentence #1 it's preceded by the preposition in. And I have never seen this phrase is used without a preposition. I believe dropping the preposition is wrong, according to the grammar.]  She made a pickle a different way from her mother. [a different way is a noun phrase, where the head is way, but strangely there is no preposition before it. But I have seen examples of a different way used both with prepositions and without prepositions. I think the preposition here is optional.]    Now from these example sentences I have tried to demonstrate my problem/confusing area. My question is - 1. When a noun phrase is used as an adverb phrase? 2. When before a noun phrase the placement of preposition is obligatory (like sentence #2)? And where it's optional (like sentence #3)? And where placing the preposition is wrong (like sentence #1)? Chemical potential of particles with zero mass Why massless particles have zero chemical potential? UV mapping not filling faces var self = this? Using instance methods as callbacks for event handlers changes the scope of this from "My instance" to "Whatever just called the callback". So my code looks like this  function MyObject() {   this.doSomething = function() {     ...   }    var self = this   $('#foobar').bind('click', function(){     self.doSomethng()     // this.doSomething() would not work here   }) }   It works, but is that the best way to do it? It looks strange to me. How to show that the nth power of a $n \times n$ nilpotent matrix equals to zero $A^n=0$ How do you handle the varying sizes of filters in your kit? I have a variety of Nikon DX lenses that take differently sized filters. Most take 52mm filters, but there are a few that take larger 67mm or 77mm filters. The advice I've read most commonly online is to buy one filter size and get filter conversion rings to step up to that size filter. In my case, the largest size appears to be 77mm.  So, I walked into a couple local photo shops and asked about 52mm-77mm filter conversion rings and they looked at me like I had two heads. One guy suggested I stack a 52mm-67m and a 67mm-77mm. I have found 52mm-77mm rings online, so I know they exist.  Is this not a common thing to do? How does the stack exchange community handle the varying sizes of filters in their kit?  Thanks, PaulH Proving $\lim \frac{x^n-a^n}{x-a}=n\cdot a^{n-1}$ How to compare the output of \ref to a number? $k^{\phi(l)} + l^{\phi(k)} \equiv1\pmod{lk}\,$ if $\,\gcd(l,k)=1$ I would like to prove the following equality: $$k^{\phi(l)} + l^{\phi(k)} \equiv1\pmod{lk}$$if $\gcd(l,k)=1$. What methods can I use? Thank you for your help. Continuous injective map is strictly monotonic 2.81.16 No Rock Generator Recent fluid-mechanical experiments by the groups of Couder in Paris and Bush at MIT, mimic a surprisingly wide range of quantum effects. The essential ingredient of these fluid-mechanical systems is a background or pilot-wave that guides the droplets.  Now, surprisingly, a simple analysis of a Bell-type experiment shows that, in the presence of a background field, one of the premises of the Bell inequality, namely measurement independence (MI), is violated. See the paper  (available ). Therefore such classical droplet experiments could violate a Bell inequality. More importantly, if this analysis is correct, background-based hidden-variable theories are admissible, even if they are local (in the sense of ‘involving only (sub)luminal interactions’) and even if they are compatible with free will.   My question: to me the analysis seems fully sound, but maybe there is still an unphysical hypothesis that slipped in ? Word or phrase for making something seem better by comparison What is a word or phrase that expresses the idea of purposely making something seem better by comparison? For example, lemon Starburst was created to make the cherry flavor seem that much tastier. Why does a helium filled balloon move forward in a car when the car is accelerating? I noticed that when I had a helium filled, latex balloon inside of my car, it moved forward in the cabin as I accelerated forward. The faster I accelerated forward, the faster the balloon went from the back of the car to the front of the car. The balloon didn't have a string.  This became a game with my 4 year old as we drove home. We figured out where the balloon would go based on how fast I accelerated, turned corners etc.  I expected that it would act a lot like the water in a cup does, but it was the total opposite it seemed.  What forces caused this behavior?  I assumed it has something to do with the fluid dynamics in the closed cabin, but I can't figure it out. How to exclude a package from apt-get autoremove? I'm in a situation where the list of orphaned packages to be removed by apt-get autoremove includes a package that I want to keep. Apparently I have accidentally removed a package which was depending on it. How can I now mark the package as explicitly desired, so that apt-get autoremove will not remove it? Using --exclude with the du command This is probably something basic but I'm not able to make it work. I'm trying to use DU to get a total size of files minus certain directories. I need to exclude one specific directory called uploads but not every directory called uploads. For example, my file structure looks a bit like this:  /store   /uploads     /junk_to_ignore     /more_junk_to_ignore   /user_one     /uploads   /user_two   I can run the following command:   du -ch --exclude=uploads*    and it gives me the file size minus all the "uploads" directories. However, in trying to exclude certain directories (and all its sub-directories) I fail. I've tried variations of:  du -ch --exclude=./uploads* du -ch --exclude='/full/path/to/uploads/*'   but can't seem to figure it out. How do I exclude a specific directory? SSH tunnelling with multiple dynamic port forwardings I am trying to monitor multiple JVMs running on different servers through an ssh tunnel.  Thanks to one of the UNIX gurus here, I have managed to get this running for a single server by:   Run jstatd on the target server Set up Visual VM to use 9696 as its socks proxy port. On my local PC, run:  ssh -L 2222:server1:22 bastion-host  On my local PC, run:  ssh -o port=2222 -D 9696 -L 1099:localhost:1099 localhost    This does the trick. Now when I try and tunnel to a second server I try:   On my local PC, run:  ssh -L 3333:server2:22 bastion-host  On my local PC, run:  ssh -o port=3333 -D 9696 -L 2099:localhost:1099 localhost    However, the last step complains with:  bind: Address already in use channel_setup_fwd_listener: cannot listen to port: 9696   Has anyone managed to do something similar?  Update:  The reason this is so complex is that jstatd is an RMI server application:    As with RMI applications, these register with an rmiregistry. Using rmi through a firewall requires me to use SOCKS as described here:    Unfortunately, visualvm only lets me set the SOCKS proxy port once, and the -D option won't allow me to forward the same local port to both servers...