We are migrating some Windows pc's to Linux (Ubuntu 14.04). For Windows we have a tool to manage those devices:   checking invetory on pc's (which software is installed) pushing software to the clients (batch / bash scripts) taking over the pc's   I saw that Ubuntu has a tool called landscape. Is there a free opensource alternative for this? Which is capable of the things I described?
Better yet, are there any Spacewalk-like software packages that work for both RedHat-based and Debian-based systems?
Let $X_1,X_2,\ldots,X_n$ and $A_1,A_2,\ldots,A_n$ be real numbers taken at random, and $\alpha\gt0$. Show that: $$\sum_{k=1}^n |X_kA_k| \le \frac{1}{\alpha}\sum_{i=1}^n X_k^2 + \frac{\alpha}{4}\sum_{k=1}^n A_k^2$$ Using QGIS3 Processing algorithms from standalone PyQGIS scripts (outside of GUI) I'm writing a script which must work outside of QGIS GUI. I call some API functions from qgis.core but I'd like to use the processing plugin.  I'm able to import processing with sys.path.append() but I can't run any process. Moreover, all "native" algs are missing in QgsApplication.processingRegistry().algorithms()  So is it possible to run processing that way ? What am I missing ?  import os, sys from qgis.core import * QgsApplication.setPrefixPath('/usr', True) qgs = QgsApplication([], False) qgs.initQgis()  sys.path.append('/usr/share/qgis/python/plugins') from processing.core.Processing import Processing Processing.initialize() import processing  layer1 = QgsVectorLayer('data/ROUTE_PRIMAIRE.SHP') layer2 = QgsVectorLayer('data/ROUTE_SECONDAIRE.SHP')  processing.run('qgis:union', layer1, layer2, 'test.shp') # returns nothing   I'm on QGIS 3.0.1 - Debian 9 Complement of maximal multiplicative set is a prime ideal Let $R$ be a commutative ring with identity. I've been trying to prove the following:     If $S \subset R$ is a maximal multiplicative set, then $R \setminus S$ is a prime ideal of $R$.   I have spent some time in it, but nothing is coming to my mind. Any idea/solution will be appreciated. How to force file download with PHP I know Blender is free software and bugs happen. But my question is, is it good practice to update Blender every time there is an update? Even if a minor one? (i.e I'd consider 2.56 to 2.56b minor or even 2.63, no?)  I haven't been updating very often for fear that updating frequently causes issues like broken settings, non-compatibility or lost user configs?  Or is updating often recommended to keep up to date and adapted to the new changes, i.e like upgrades in the GUI and functionality? Why is "chmod -R 777 /" destructive? This is a  about File Permission and Why 777 is "destructive".   I'm not asking how to fix this problem, as there are a ton of references of that already on Server Fault (reinstall OS). Why does it do anything destructive at all?  If you've ever ran this command you pretty much immediately destroy your operating system. I'm not clear why removing restrictions has any impact on existing processes. For example, if I don't have read access to something and after a quick mistype in the terminal suddenly I now have access well... why does that cause Linux to break? Did Stephen Baxter or Arthur C. Clarke's estate ever comment on continuing "A Time Odyssey"? 2007 book "Firstborn", the third and last book of "" trilogy by Stephen Baxter and Arthur C. Clarke - an "orthoquel" to "2001: A Space Odyssey" - ends with a cliffhanger which obviously implies continuation:      Myra said, “My God.Charlie? ”  Bisesa stared. “Who is ‘we’?”  “We call ourselves the Lastborn. We are at war. We are losing.” She held out her hands. “Please. Come with me now.”  Bisesa and Myra, still hugging each other, reached out their free hands. Their fingertips touched Charlie’s.  A clash of cymbals.   However, sadly, Sir Arthur died in 2008, with no further books forthcoming.  Did Stephen Baxter  or Arthur C. Clarke's estate ever comment on continuing "A Time Odyssey" after 2008?  Wikipedia has no info:     The 2008 Gollancz edition of the most recent book describes itself on the cover as the "Conclusion" of the series, but the plot is not concluded in the book. The immediate threat is averted but the enemy is not defeated, suggesting that further novels in the series were intended. With the death of Clarke, one of the two authors, it is not clear whether these will be written. What do the .eh_frame and .eh_frame_hdr sections store, exactly? I have been playing with Ubuntu for a few weeks now, and I'd like to revert my computer back to it's original - factory - defaults.   On the computer I have a recovery partition (it's a netbook). I went through the process of recovery and everything seemed fine. However, when I restart the computer I'm presented with   grub rescue &gt;   Now, my understanding is that when I installed Ubuntu "side by side" it replaced the MBR or something like it, with GRUB.   I've read on a slew of forums, that I need to use a Windows Recovery Disk.   Here are my issues:   a) I don't have a recovery disk, I have a recovery partition - it's a netbook. b) I don't have an external cd drive.   What I do have is a USB key that has about 1gb of space on it.   Thanks in advance. I solved the Lagrangian of a simple pendulum (with help from online examples as this concept is new to me) and ended with the following: $$\ddot{\theta}+\omega^2\theta=0$$ But in the example I was following, the next line written was this: $$\theta(t) = A\cdot\sin(\omega t + \Phi)$$ And I don't know what steps they took to get there? Consider $\mathbb R^{[0,1]}$ the space of all functions from $[0,1]$  to $\mathbb R$  and the cylindrical sigma algebra $\mathcal B$  on it. The question is: how to prove that $C[0,1]\notin \mathcal B$. Introductory Calculus textbook for physics? I have the summer to prepare myself for a high school calculus-based physics course; however, I will have to study calculus by myself. I've completed a course in precalculus and I'm beginning to read .   I am looking for a textbook that has mathematical rigor (i.e. not memorizing formulas), yet also provides adequate foundations for a physics course. From similar stack exchange questions, my top candidates are  and . Which one of these textbooks, if any, would be the best choice for my situation? I am trying to build a computer, placing an  in a custom .  The case is an extra small form factor which can accommodate the Mini ITX board, but it requires an external power supply, similar to the power-bricks that laptops use.  I am looking at different power supplies and like , but I cannot figure out whether/how to power this system, because they provide a 24-pin connector, but the motherboard has a 4-pin connector as well.  Is the 4-pin connector optional or is it required? If it is required, how can I provide power for this system? What is strain? Why does DNA coil upon itself? I have been reading Lehninger's Principles of Biochemistry to understand DNA supercoiling (pg-). Supercoiling is the twisting of a DNA upon itself and this happens when the two helically wound strands of DNA are either underwound or overwound. The book says that this act of underwinding or overwinding generates a structural strain  which is then accommodated by coiling of the DNA upon itself (supercoiling). Here the word strain has been used in the way stress of mechanical physics would be used. I wonder if it means stress. Besides I would like to know how underwinding or overwinding cause the DNA to coil upon itself. Excerpts from the book:  DNA supercoiling is generally a manifestation of structural strain. Most DNA are negatively supercoiled (which means that the supercoiling is left handed). In almost every instance, the strain is a result of underwinding of DNA double helix. Supercoiling is not a random process; the path of the supercoiling is largely prescribed by the torsional strain imparted to the DNA....  Torsional strain, again is it talking about ? P.S. The description of the question has been changed recently. Eclipse CDT - Copy static resource file to bin_dir What do hollow/filled stars mean in chat? I was on chat in Stack Overflow and noticed that some of the message had grey stars with a black border while others were just black stars. What is the difference between the 2 star types? System.CalloutException: You have uncommitted work pending I have same exception can please   The previous post issue is resolved.  Exception: :System.CalloutException: You have uncommitted work pending. Please commit or rollback before calling out  Visualforce Page   &lt;apex:page controller="Controller" action="{!init}" showHeader="false" sidebar="false"&gt;     &lt;center&gt;         &lt;apex:pageBlock title="Request Listener"&gt;&lt;/apex:pageBlock&gt;               &lt;/center&gt; &lt;/apex:page&gt;   Controller :            PUBLIC with sharing class Controller {        PUBLIC String fromNumber      = ApexPages.currentPage().getParameters().get('From');     PUBLIC String toNumber        = ApexPages.currentPage().getParameters().get('To');     PUBLIC String body            = ApexPages.currentPage().getParameters().get('Body');        PUBLIC PageReference init()     {                    System.debug('From Phone Number :' +fromNumber);         System.debug('To phone NUmber :' + toNumber);         System.debug('Message Body :' + body);          TwilioRestClient Client = TwilioAPI.getDefaultClient();                                                                SYSTEM.DEBUG('FROM AND To  Number is NOT NULL');                      String formattedNumber='+919876543210';                 IF(body != NULL)                 body = body;             ELSE                 body = '';             Case c = NEW Case (Subject = formattedNumber,Description = body,Origin = 'Phone');             INSERT c;                               Map&lt;String,String&gt; params1 = new Map&lt;String,String&gt;             {                'To'   =&gt; fromNumber,                'From' =&gt; '+1908280****',                'Body' =&gt; 'Conformation to customer'             };             TwilioMessage message = client.getAccount().getMessages().create(params1); /* Valid conformation SMS sent to the Customer.*/                                            return null ;     } }   While loin as admin then click preview on visualforce page executed but case is not created.I have checked the the debug log it throw the exception. I want to know if there is another way to solve the equation:  $$(x+1)^y-x^z=1$$  for positive integers $x,y,z$ greater than $1$ without using the Catalan identity. Does exist? By now I only know that $x\mid y$. Removing Firefox in Ubuntu with all add-ons like it never existed I have been using Firefox for a long time in Ubuntu, I downloaded some add-ons but it made firefox extremely slow, even if I remove them nothing will change.  I tried to remove Firefox also, but re-installing it will somehow recover the same Firefox I had- it seems it write some info somewhere that even if you remove Firefox, it will keep them.  Moreover, I am not able to use see any flash videos or website with Firefox(chrome works fine).. Honestly I tampered with plug-in settings in Firefox that this happened. But right now I can't do anything to overwrite the setting...  My question is how I can remove Firefox in a way to remove any previous traces and re-install a new version like for the first time? I have a Virtual machine using centos 7 with 200GB disk.For some reason my layout is:  df -h Filesystem               Size  Used Avail Use% Mounted on /dev/sda1                100GB  95GB  5GB      Running fdisk -l:  Disk /dev/sda: 204.8 GB, 204803670016 bytes,400007168 sectors  Units = sectors of 1 * 512 = 512 bytes  Sector size(logical/physical): 512 bytes / 512 bytes I/O size(minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x0006c283  Device Boot      Start         End      Blocks   Id  System /dev/sda1            2048   199997439    99997696     Linux   I would like to increase my space on my partision /dev/sda1.