LVM Snapshot Tutorial on Ubuntu Server
Setting up LVM Snapshot as a backup/restore point in ubuntu
Using C# .NET 2.0, I have a composite data class that does have the [Serializable] attribute on it.  I am creating an XMLSerializer class and passing that into the constructor:  XmlSerializer serializer = new XmlSerializer(typeof(DataClass));   I am getting an exception saying:      There was an error reflecting type.   Inside the data class there is another composite object.  Does this also need to have the [Serializable] attribute, or by having it on the top object, does it recursively apply it to all objects inside? Local collection of Python packages: best way to import them? App Store is the wrong language `du -sh` reports different used size than `df -h` Possible Duplicates:             df -h says that I have 494G used on /var:  Filesystem            Size  Used Avail Use% Mounted on /dev/sda3             564G  494G   41G  93% /var   But du -sh /var says it's 350G  What makes them different? Is there a way to get "people reached" sum across entire network for a user? The New Model profiles on Meta.SE (pretty big improvement!) have a section for "" stat.  Now, unless I'm much mistaken, that stat is specific to a given site on the network.  If that assumption is indeed correct, is there a way to find out the "People Reached" summary across 100% of the sites on the network for all your connected profiles? Constraint the camera to look at an object In my scene I have a camera sitting at the origin. I would like to contraint it so that it always looks at the center of a given object. But the camera should not change its position.  I found some answers using a "TrackTo" or "LockedTrack" constraint but could not manage to make it work.  Could I probably use a Driver for this and if yes, how can I adjust it?  Thanks in advance! Series about being that could change sex and age - "The Morph*" I'm trying to remember information about a series of three books I read in the early 1980's (first book could have been published in the 1970's). The book featured a character who was a scientific creation of some sort. It was (initially, I believe) an assassin, and had the ultimate getaway scheme; with effort, it could change its body, becoming about 10 years younger and switching sex. It changed 4 or 5 times in the first book, coming down from a senior citizen to someone in their teens or twenties; in the second and third books, it changed once per book (by the last book, it was a child or a young teenager).  The first book was title something like "The Morph..." where whatever the word was that started with "Morph" was this creature. No recollection of the author's name, or the titles of the other two books.  I think the cover of the first book was predominantly yellow, with black silhouettes representing the character at the four ages seen in the book, and a black title. And/or, the book might have been published by DAW (all their books at the time had yellow spines with black letters). I am dissecting some code and came across this,   $sql = 'SELECT page.*, author.name AS author, updator.name AS updator '      . 'FROM '.TABLE_PREFIX.'page AS page '      . 'LEFT JOIN '.TABLE_PREFIX.'user AS author ON author.id = page.created_by_id '      . 'LEFT JOIN '.TABLE_PREFIX.'user AS updator ON updator.id = page.updated_by_id '      . 'WHERE slug = ? AND parent_id = ? AND (status_id='.Page::STATUS_REVIEWED.' OR status_id='.Page::STATUS_PUBLISHED.' OR status_id='.Page::STATUS_HIDDEN.')';   I am wondering what the "?" does in the WHERE statement.  Is it some sort of parameter holder? How to run updmap-sys after installing cm-super? My original question was:   The answer that seems suitable to my cause is to install cm-super. I did that (using package manager [winxp 32 bit, MikTex installation 2.9 recently updated]). But still the command  \usepackage{cm-super}    yields an error.  User H Cavendish suggested to run updmap-sys, but I am not sure about how to do that on WinXP.   2011 November 04 edit: I made it sure that I have installed 'cm-super' - but still get the same error:   I have also tried updating the file name databases - but no avail. How do I post text so that it is formatted as code?  What do I need to do so that my code shows up properly &mdash; not escaped or removed &mdash; when posted? And how to get the correct syntax highlighting?     For more information, see "" in the . Uniform Scattering with vector I'm attempting to create a random spread of dots to create a gradient look. I'm getting really close to the effect I want by blending two scatter brushes. The issue I'm having is that the blended brushes creates unwanted lines, and the dots run into each other. I keep adjusting the settings with no luck.  Here's the effect I'm wanting to achieved.    Smooth transition  On Circular path Dots don't converge Scattered at random-ish     Here's how close I'm able to get:   Blended scatters create unwanted lines Dots converge Spacing isn't gradual from edge to center Find the volume common to two circular cylinders, each with radius r, if the axes of the cylinders intersect at right angles. (using disk/washer)  I saw no example of this problem anywhere.. I saw an example how to solve it without calculus but I'm afraid that'll be deductions on my test.. I have the volume of a cylinder and the method of area between two curves but this is out of my reach.... I don't know what I can try... Prove or disprove: If H is a normal subgroup of G such that H and G/H are abelian, then G is abelian. it seems like it... should be? In that I can't think of any counterexamples off the top of my head. I was looking up these  and saw the quaternion group, but the subgroups of the quaternion group aren't abelian... Recently I decided to use only Ubuntu and there is no Windows in my laptop. When I turn on my laptop the GRUB menu is showing but I don't need to choose OS anymore.   How can I remove or hide this? And after removing this how could I access to recovery mode? Possible point location algorithm I need to calculate possible point location based on its speed and some other factors. For example, there is a man in the middle of the forest and I need to calculate his possible location at some time periods. There are few facts about his movement:   His speed differs at certain periods of time - it can be raining, or it can be super hot - speed lowers / increases; Some objects in space - swamps, rocks - can lower his speed as well; At some time periods the man does not move at all.   So, here is the question - is there any algorithm that can calculate possible location of the man based on following parameters? The output should be a polygon for every given time_period.  {   time_periods: [{     from: 2012-12-12T20:00:00,     to: 2012-12-12T22:00:00,     speed: 5   }, {}],   objects: [{     geodata: POLYGON(...),     speed_modifier: 0.5   }, {}] }   Generated polygons will be visualized on the map afterwards. Is there a way to show statistic info? Is there a way to get Statistic info in Blender? Or heads up display? Like when I select a group of vertices, I need a way to know how many vertices are selected and How many polygons "or triangles my scene has. Derivation of $E=pc$ for a massless particle? In classical mechanics, massless particles don't exist because for $m=0$, $p=0$.  The relativistic relation between energy, mass and spatial momentum is: $E^2= (pc)^2 + (mc^2)^2$ . So it is said that setting $m=0$ in the first equation you get $E=pc$.  How could setting $m=0$ in that equation give you $E=pc$ whilst $p$ appears in the equation and we know $p=γmu$? If you set $m=0$ you will have indeterminacy due to "$γm$". It seems to me like we are doing a "trick" in order to get the $E=pc$. Perhaps there is another proof for this relation? How to Truncate a string in PHP to the word closest to a certain number of characters? I have a code snippet written in PHP that pulls a block of text from a database and sends it out to a widget on a webpage.  The original block of text can be a lengthy article or a short sentence or two; but for this widget I can't display more than, say, 200 characters.  I could use substr() to chop off the text at 200 chars, but the result would be cutting off in the middle of words-- what I really want is to chop the text at the end of the last word before 200 chars. Is there anyway to get tuple operations in Python to work like this:  &gt;&gt;&gt; a = (1,2,3) &gt;&gt;&gt; b = (3,2,1) &gt;&gt;&gt; a + b (4,4,4)   instead of:  &gt;&gt;&gt; a = (1,2,3) &gt;&gt;&gt; b = (3,2,1) &gt;&gt;&gt; a + b (1,2,3,3,2,1)   I know it works like that because the __add__ and __mul__ methods are defined to work like that. So the only way would be to redefine them? How to change the chapter number to display as text (One, Two, ...)? In LaTeX, how do I change the chapter number to display as text? eg:  CHAPTER ONE not CHAPTER 1;  CHAPTER THIRTEEN not CHAPTER 13.