I am running a server with 24G of RAM. The only thing running here is a MySQL server configured as Master.  When I check the memory via free -m I am getting this:               total       used       free     shared    buffers     cached Mem:         24158      24027        131          0        131      23050   Approx. 23G is in cache. Which seems a lot to me.   I also set caching to 0 in the my.cnf  query_cache_size        = 0   How can I check what is exactly cached?  Also a restart of mysql doesn't clear the cache. A flush tables also didn't help.
This is a  about how Unix operating systems report memory usage.   Similar Questions:                    I have production server that is running Debian 6.0.6 Squeeze  #uname -a  Linux debsrv 2.6.32-5-xen-amd64 #1 SMP Sun Sep 23 13:49:30 UTC 2012 x86_64 GNU/Linux   Every day cron executes backup script as root:  #crontab -e  0 5 * * * /root/sites_backup.sh &gt; /dev/null 2&gt;&amp;1   #nano /root/sites_backup.sh  #!/bin/bash str=`date +%Y-%m-%d-%H-%M-%S` tar pzcf /home/backups/sites/mysite-$str.tar.gz /var/sites/mysite/public_html/www mysqldump -u mysite -pmypass mysite | gzip -9 &gt; /home/backups/sites/mysite-$str.sql.gz cd /home/backups/sites/ sha512sum mysite-$str* &gt; /home/backups/sites/mysite-$str.tar.gz.DIGESTS cd ~   Everything works perfectly, but I notice that Munin's memory graph shows increase of cache and buffers after backup.  Then I just download backup files and delete them. After deletion Munin's memory graph returns cache and buffers to the state that was before backup.  Here's Munin graph:  Externally hosted image was a dead link.
Is it possible to trade Pokemon from the 1st generation games to the most recent ones? I know that you can trade Pokemon between games of the same generation (Gold/Silver, Ruby/Sapphire) and even trade between 1st gen and 2nd gen. However, I haven't been able to find a way to trade Pokemon so that I can play with my 1st generation Pokemon in HeartGold, for instance. If it is possible, how many steps would it take and what equipment would I need? Error message "sudo: unable to resolve host (none)" When I run sudo the terminal is stuck for a few seconds and then outputs an error message. My terminal looks like this:  ubuntu@(none):~$ sudo true sudo: unable to resolve host (none)   What can I do to solve it? How to install a deb file, by dpkg -i or by apt? Subscribing to questions and comments that don't belong to you There has been some discussion about getting notified on comments to questions or answers that don't belong to you, and the long-standing wish to be able to keep track of new answers or developments in questions asked by other people.  Previous discussion in regards to subscribing to questions:                  (very similar to this one)      In regards to subscribing to comments:                    The general feeling - at least here on meta - seems to be against broadening the notification rules, out of fears of useless notifications to flood users' inboxes, turning SO into more of a discussion forum than it should be, etc.   Here's a suggestion that would keep the user 100% in control what they get notified about, not generate any notifications by default, and require only minimal modifications to the User Interface.  Each question and each comment area would get an envelope symbol.    it is inactive (=white) by default.  When those envelopes are hovered over, the tooltip says click to subscribe or something.  When clicked on, the envelope lights up in green or some other colour (but different from the actual notification envelope's orange to avoid confusion.) You are then subscribed to any updates to that question or comment thread.    For each subscription, you receive notifications in the "responses" tab, as if you were the owner of the comment or question.     To unsubscribe from a question or comment thread, you open the page, and click the green envelope. It turns back white, and the notifications disappear from your responses tab (if technically possible - otherwise, there just won't be any new ones added.)    No further functionality, like managing subscriptions or anything, is necessary IMO. If the flood of notifications from a subscribed question starts to annoy you, you just open it and unclick the envelope. Done.   It would make it possible to leave a comment to a newbie's question and make sure their answer reaches you even if they don't know they need to address you using @username You could subscribe to those "oh, I'd like to know the answer to that" questions and receive active notification, instead of them getting forgotten in your favourites list You could subscribe to discussions you are interested in the outcome of, but don't want to participate in. It would (in my opinion) sort out a number of woes aired by many users in a good way, without adding annoyances to those who like the system just fine the way it is. It would not require a change in the visible layout. As far as I can see, the space the envelope would need to be is empty everywhere.   I don't know SO under the hood of course, but technically, the system would be doing what it's doing already, notify question owners of updates - just that the circle of internal "owners" would grow. Now that I know , I was wondering how I can restart the phone or turn it off.  The lock button is completely unresponsive and holding it down does nothing. Are there any workarounds besides replacing the button? Are there any simple rules for choosing the definite vs. indefinite (vs. none) article? suppress page numbers in document's front matter I have a problem and I want that someone tell me how I can resolve that.  I want that the number of page in my report start in the page of introduction but in reality it starts in the didecas and liste of contents. I want that these pages have not number. This is my code  \documentclass[12pt,a4paper]{report} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage[french]{babel} \usepackage{color} \usepackage{xcolor} %les couleurs \definecolor{myblue}{rgb}{0.2,0.4,1} \usepackage{layout} \usepackage[top=2 cm, bottom=2 cm, left=2 cm, right=2 cm]{geometry} \usepackage{setspace} \usepackage[pdftex]{graphicx} \usepackage{array} %\documentclass[landscape]{scrartcl} \usepackage{geometry} \usepackage{multirow}  \usepackage[justification=centering]{caption}  \usepackage{pgfplots}   \usepackage{fancyhdr} \fancyhf{} % clear all header and footers   \begin{document} \pagestyle{empty} \include{title-content} \color{black} \doublespacing \include{dedicaces-content} %\include{remerciement}   \tableofcontents  \listoffigures \listoftables     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \pagestyle{plain}  \pagenumbering{arabic} \chapter{Introduction générale} What is the difference between a relative phase and a global phase? In particular, what is a phase? I know that $re^{i\theta} = x + iy$ for any complex number $x + iy$ by Euler's formula. How do you calculate relative and global phase? I have build a website for a finance company.  The Cognito Form is on the website as an application form.  I would like the information sent automatically to the finance company's email address (as soon as the form is submitted) without having to log into Cognito Forms. The finance company needs to know the exact moment the application for finance comes in. The finance company can not possibly log in to Cognito Forms 24/7 to check if there are any finance applications. Should reputation points expire? While looking at the SO question  It occurred to me that this was an extremely simple question with an extremely simple answer.  And yet, it has garnered the OP thousands in upvote points, simply because he was the first one to ask this question in the early days of SO.  There are many examples of these simple questions and I believe they don't accurately model a user's participation in the SO community.  People shouldn't be getting thousands or even tens of thousands of points from a question just because they were lucky enough to get it in the system a while ago.  Another related issue is that the non-expiring point system rewards users for seniority.  Simply put, the longer you're around SO, the higher your score will be.  While there's some merit to this, it seems to have a disproportionate effect.  So what can we do to limit these effects?  I'm just brainstorming but here are a couple ideas:   Automatically close voting on questions after a certain time period.  Good questions will still be rewarded, but they won't give disproportionately large rewards simply because they are really old questions. Expire users' points after a certain time period.  If you expire users' points after, say 3 months, then this will force them to stay active and their points will be more a reflection of "How much have you participated lately"?  It forces old users to stay active rather than resting on their laurels, and allows junior members a chance to catch up to senior members of the community by putting in a lot of effort.  Currently, there is no chance at all for junior members to ever catch up with senior members and their only 'sin' is that they didn't register 5 years ago. When looking at used camera bodies, a question that comes up a lot, is "how many shutter actuations, or clicks, does it have?"   What I am wondering is, how many is too many. In other words, is there a reference for knowing when a sensor is more likely to go? How should I judge a camera body with 20000 vs 5000? Is that a significant difference, or is that not even relevant.  Obviously this might something that is dependent on model, so if there is some information based on model that would be even more interesting.  One of the guys at Canon Tech Support said that this is completely irrelevant for the Rebel series cameras, but he is obviously slightly biased. :) How can I make an application automatically start when I have logged in? Add an API key to QGIS for QOSM layer I'm considering buying the MacBook Pro (Late 2016) with Touch Bar. As I'm a programmer and a Ubuntu user, could anyone tell me if the Touch Bar is compatible with Ubuntu? I recently installed Ubuntu 17.10, and when I tried to set my keyboard layout to change with alt+shift, I hit a . There is  which works, but then it creates an unwanted behaviour on Firefox (perhaps other programs as well).   After setting alt+shift through gnome-tweak-tool as the combination to change language, whenever this combination is pressed within Firefox, it triggers a toggle that Firefox uses to show/hide the Menu Bar (with File/Edit/View etc.), and 'focus' is taken away from wherever the cursor was.   It's very frustrating, because one has to go and click again at the cursor.  The only solution I found was to permanently enable Menu Bar in Firefox because then alt doesn't do anything and I can use it to change languages. But I don't want to have Menu Bar on top always.  I hope you can understand what I'm trying to explain.  Any thoughts? I have trouble on this question: "Characterize the groups G for which the map $$\iota: G \to G$$ sending $$x \mapsto x^{-1}$$ for all $x \in G$, is an automorphism of $G$." From  post I have seen that $G$ must be abelian. Can anyone propose another characteristic of $G$ that I can derive from the given conditions besides abelian? Thank you so much!! Avoiding Windows 10 Creator, but not other updates If $G$ is a group, show that $x^2ax=a^{-1}$ has a solution if and only if $a$ is a cube in $G$ I was checking my old set of homework problems that I found this one:     If $G$ is a group, show that $x^2ax=a^{-1}$ has a solution if and only   if $a$ is a cube in $G$.   One direction is easy. If $a$ is a cube in $G$ then there exists $y \in G$ such that $a=y^3$. Now with direct manipulations it is shown that $x=y^{-2}$ is a solution to $x^2ax=a^{-1}$.  The other direction is harder though. I first attempted to isolate $x$ and then somehow show that it's necessary for $a$ to be a cube. But since I had no idea how to isolate $x$ I gave up. Then I decided to prove the existence of $y \in G: a=y^3$ by showing that a particular map is bijective so I can come up with a nice variable change to conclude that $a$ must be a cube, but this attempt failed as well. I'm tired now, so I think I'm giving up. I'm looking for a hint or a complete solution if a hint is not possible at this stage. Which "mean" to use and when? So we have arithmetic mean (AM), geometric mean (GM) and harmonic mean (HM). Their mathematical formulation is also well known along with their associated stereotypical examples (e.g., Harmonic mean and it's application to 'speed' related problems).  However, a question that has always intrigued me is "how do I decide which mean is the most appropriate to use in a given context?" There must be at least some rule of thumb to help understand the applicability and yet the most common answer I've come across is: "It depends" (but on what?).  This may seem to be a rather trivial question but even high-school texts failed to explain this -- they only provide mathematical definitions!  I prefer an English explanation over a mathematical one -- simple test would be "would your mom/child understand it?" Is there such a thing as a Ubuntu Certified Engineer?