I tried an in-memory Linux distro and I was shocked by how fast it was.  Is there is a way to always cache in memory some (user specified) software like the file explorer so that you can benefit of that speed without having to preload the whole system in the memory (unfeasible if it's your main desktop because there would be not enough memory)
My PC has 8 Gb of ram. Is there any way to make ubuntu use most of it? I mean rarely drop caches and keep once opened programms in ram longer, preload apps on boot, etc.
Opacity of background-color, but not the text How do I make the cross-browser (including Internet Explorer 6) transparency for the background of a div while the text remains opaque?  I need to do it without using any library such as jQuery, etc. (But if you know of a library that does it I'd love to know so I can look at their code). In (non-relativistic) classical physics, if the temperature of an object is proportional to the average kinetic energy ${1 \over 2} m\overline {v^{2}}$of its particles (or molecules), then shouldn't that temperature depend on the frame of reference - since $\overline {v^{2}}$ will be different in different frames?  (I.e. In the lab frame  $K_l = {1 \over 2} m\overline {v^{2}} $, but in a frame moving with velocity $u$ relative to the lab frame, $K_u =  {1 \over 2} m \overline {(v+u)^{2}}$). I have installed Ubuntu 13.04 on my desktop (runs like a charm). Then I used Crouton to install Ubuntu 12. 04 on my chromebook samsung (ARM). It also works quite well.  Here comes my question. Can we have a true Ubuntu (preferably 13.04) on my ARM chromebook?  It seems that the Crouton/Ubuntu is not 100% the real thing.  The best option would be to have the full Ubuntu 13.04 and remove the Chrome OS. For $x$ and $\lambda$ complex, if $|x| \gt \frac{1}{2} + \sqrt{\frac{5}{4} + |\lambda|}$ then $|x^2+\lambda| \gt |x| +1$ The Winter Bash is back and the hats are listed below.  As always, there are only two answers: one for the secret hats, and one for the regular hats. The secret hat list will be updated as we learn them.  Only edit the secret hat answer with definitive and correct triggers. This is not the place to post guesses.    If you'd like to discuss Winter Bash, hats or just have a question about the WB please come over to the .  Please keep the comments here clean. As always comments are not meant for discussion, conversation, "I just got hat X", etc use the  for that (the remaining meta mods will periodically clean the comments). I know you are excited you just got a secret hat, but please instead of posting a comment come over to the  and tell us all there.  Provided that "It's important to know your history... in more ways than one"  again this year, here are the hats from prior years: This integral is very closely related to the sophmores dream that states  $$ \int_0^1 x^{-x}\mathrm{d}x = \sum_{n=1}^\infty n^{-n} = 1.27\ldots $$  For example here   Now I want to bound the integral, and showing that is less that 2.  For the interval $[0,1]$ a good bound is rewriting it to $\exp(x\log x)$ and using the expansion   $$ 1 - x \log(x) + \frac12 (-x \log(x))^2$$  but how does one handle $[1,\infty)$ ? In this answer here     gives bounds to the integral, but they are not tight enough.. So to taste my question again, how does one prove that   $$ \int_0^\infty \frac{\mathrm{d}x}{x^x} \leq 2 $$ Some say that we can connect two points with a continuous curve and a small contractible neighborhood of the path together with the charts of the points can be regarded as the chart. But I don't know how to verify this statement. Row colour gaps in tabularx with \aboverulesep and \{} \documentclass[]{article} \usepackage[table,dvipsnames]{xcolor} \usepackage{multicol,booktabs,tabularx}  % Table settings \renewcommand{\aboverulesep}{1pt} \renewcommand{\belowrulesep}{1pt}  \begin{document}     \begin{tabularx}{\textwidth}{@{}X l@{}}         This is Header 1 &amp; This is Header 2 \\         \toprule         \rowcolor{Apricot}         This is Text 1 &amp; This is Text 2 \\\midrule         This is Text 1 &amp; This is Text 2 \\\midrule         This is Text 1 &amp; This is Text 2 \\         \bottomrule     \end{tabularx} \end{document}   I have the above table MWE using tabularx, and I am trying to colour the row from the table. However, due to the use of my \aboverulesep and \belowrulesep, I now have gaps above and below my table row that is not coloured.   Also, because of the use of my @{} on either side of the table to 'remove' the excess padding on the sides of the table, the row colour is being applied in those padding as well.   Qn 1: How can I colour the aforementioned gaps (arising due to the \aboverulesep) in, while maintaining the rule separation?   Qn 2: How to remove the colour from the two sides of the table?     EDIT  This is in response to Zarko's answer. I want to maintain the use of @{} on either side to remove the padding. If I were to adapt this into your answer, like so:  % @Zarko's answer \documentclass{article} \usepackage[table,dvipsnames]{xcolor} \usepackage{booktabs, cellspace, tabularx}  % Table settings \renewcommand{\aboverulesep}{0pt} \renewcommand{\belowrulesep}{0pt} \setlength\cellspacetoplimit{5pt} \setlength\cellspacebottomlimit{5pt}  \begin{document}     \begin{tabularx}{\textwidth}{@{}SX Sl@{}}% &lt;-- S is append for activate additional vertical space          This is Header 1 &amp; This is Header 2 \\         \toprule         \rowcolor{Apricot}         This is Text 1 &amp; This is Text 2 \\\midrule         This is Text 1 &amp; This is Text 2 \\\midrule         This is Text 1 &amp; This is Text 2 \\         \bottomrule     \end{tabularx} \end{document}   I obtain this:   and so my second question (Qn2) is still unresolved.. For Qn 1, I prefer to use the solution by @Skillmon with \renewcommand{\arraystretch}{1.15} as I need not add a new package. How does the clean Installation of Windows 10 after the free upgrade work? I have not found any information from MS - only speculations from people like me, so I hope someone here has had better findings.  When I upgrade a qualified version of Windows to Windows 10 and then want to do a clean install, I've heard that the installer won't ask for a key. But what if my HDD is formatted before I attempt the clean install? How does Windows 10 try to detect the valid "upgraded" status? It seems that it doesn't in such a case, at least as far as I've tested.  So my question is: In that (or a similar) scenario: How do you clean install Windows 10?  In my case it's actually even more complicated. I'm from Germany so I can re-use OEM-licenses due to law. I have two qualified Windows OEM licenses which I both installed in a VM on my Linux installation and upgraded both to Windows 10.  Now I want to install one of them onto my bare physical machine - how would that be possible? Is there an official way of doing this or do I need to wait for those unofficial "backup license"-tools being updated to work with Windows 10? I'm looking for an example of a finitely generated module with submodules that are not finitely generated.  I've found  dealing with group (i.e. an example of a finitely generated group with subgroups that are not finitely generated). But I can't figure out whether that question do help to this one.  And I actually want to find a more "module-like" example rather than an example derived from a 'strange' group.  Can you please help? Thank you! When is the finalize() method called in Java? mysqli::query(): Couldn't fetch mysqli How can I draw simple trees in LaTeX? I need to draw a tree, and constantly using dotty and including the PNGs is starting to be a pain. Is there a way to get LaTeX to draw it's own trees that doesn't involve learning an entirely new language like TikZ? I rent a VPS that uses a SSD of 10GB (Debian 7) and I upgraded yesterday to their "second tier" plan that uses a 20GB disk. However, the "one-click-upgrade" process didn't work as I expected and what they did was to move my data to a bigger drive without actually extending the partitions. So now I have 10GB of unallocated space.  I do run around 5 websites on this VPS with mail accounts and all that jazz and I'm very scared to mess up anything so I called their support and they offered to do the job for me for 80 EUR that I find unacceptable since I thought it was included when doing the upgrade. Their older offers from last year used to be just a one click job but the excuse is that "SSD's are different, so it's up to the user".  Anyway, how can I actually do that without screwing things up and is it possible to do that on a "live" system?  I know a couple of commands so here it goes what I could find:  root@vpsxxxxxx:~# df -h Filesystem      Size  Used Avail Use% Mounted on rootfs          9.9G  7.6G  1.8G  81% / udev             10M     0   10M   0% /dev tmpfs           388M  200K  388M   1% /run /dev/vda1       9.9G  7.6G  1.8G  81% / tmpfs           5.0M     0  5.0M   0% /run/lock tmpfs           775M     0  775M   0% /run/shm /dev/vda1       9.9G  7.6G  1.8G  81% /var/www/clients/client2/web2/log /dev/vda1       9.9G  7.6G  1.8G  81% /var/www/clients/client1/web3/log /dev/vda1       9.9G  7.6G  1.8G  81% /var/www/clients/client3/web5/log /dev/vda1       9.9G  7.6G  1.8G  81% /var/www/clients/client5/web7/log /dev/vda1       9.9G  7.6G  1.8G  81% /var/www/clients/client4/web6/log  root@vpsxxxxxx:~# fdisk -l  Disk /dev/vda: 21.5 GB, 21474836480 bytes 4 heads, 32 sectors/track, 327680 cylinders, total 41943040 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 identifier: 0x00000000     Device Boot      Start         End      Blocks   Id  System /dev/vda1   *        2048    41943039    20970496   83  Linux  root@vpsxxxxxx:~# sfdisk -l  Disk /dev/vda: 41610 cylinders, 16 heads, 63 sectors/track Warning: The partition table looks like it was made   for C/H/S=*/4/32 (instead of 41610/16/63). For this listing I'll assume that geometry. Units = cylinders of 65536 bytes, blocks of 1024 bytes, counting from 0     Device Boot Start     End   #cyls    #blocks   Id  System /dev/vda1   *     16  327679  327664   20970496   83  Linux /dev/vda2          0       -       0          0    0  Empty /dev/vda3          0       -       0          0    0  Empty /dev/vda4          0       -       0          0    0  Empty Is it possible to run Drush without root? I run a Linux server that is administered by a friend of mine, and at the moment I work with Filezilla.  I've heard that Drush is a trivial installation: it seems to require no configuration and work out of the box.   However, it looks for configuration in several places:     Drush installation directory,  the home directory (as .drushrc.php),    root directory of a Drupal installation, and  site directory of a   Drupal installation.  Since the configuration files are just PHP   scripts, they can  contain any PHP code that you would like to have   executed on startup of Drush.  one could for instance call ini_set()   to set the value of a PHP configuration option.   and the configuration file /opt/drush/drushrc.php with following content:    # Allow Drush to use 128 MB of memory. Use -1 for no limit. ini_set('memory_limit', '128M');   I see this is necessary because PHP's default is too low, but I'm not sure if I need higher-level privileges because of it.  Do I have to have root-level permissions on the server, or am I able to work with Drush without them?   Update:  As far as i understand this, i only have to ask my admin to get some more privileges (permissions)Note according to BetaRides answer i need to have more than only the access-data that the FileZilla needs - that are provided for the filezilla! Guess so - but i don not need root-permissions.  btw - i have secure-shell-access (ssh2 access) guess that this is enough -With that i can setup a sftp-connection to the server with filezilla just lemme know - if i can use the exactly same data for the shell access (with the command line tool=?!= Test -n gives unexpected result I understand test -n &lt;expression&gt; to return false if the expression evaluates to a string length of greater than 0.  Why then does the following happen?  Macbook:~ echo ${#undeclared_variable} 0 Macbook:~ test -n $undeclared_variable &amp;&amp; echo Foo Foo   Bash 4.x  My expectation is that since test -n $undeclared_variable should evaluate false, that Foo should not be echoed.  If I use [[  ]] instead of test, it works as expected. Last year I hired someone to do some work for our website but accidentally lost the PSD files since then. It's a fairly basic concept but I am fairly inexperienced with using masks.  How can I create the black circular gradient area as shown in this image below? I need to get as close as possible where it matches existing images on the site, why I am hoping its not too hard.  Thank you! How can I create an instance of the Java console inside of a GUI panel? I'm new to blender and have this issue: I'm using the "Industry Compatible" keymap. In "Edit Mode" the keys 1, 2 and 3 swap between vertex, edge and face select - Great!  Now i want to customize it, so i'm adding a new preset "My keymap". As far as i understand this now is based on the "Industry Compatible" keympap and everything works accordingly. But if i close and start blender again, the 1, 2 and 3-key aren't working anymore. I need to go back to the preferences, set the "Industry Compatible" keymap and then set back to "My keymap". Then the 1, 2 and 3-key work again as expected.  This is reproduceable on the last Blender 2.8 version on several different machines. Am i doing something wrong? Is this a bug? I read this book once when I was in middle school. A girl solves a murder or a mystery on a spaceship. It was a thin paperback books.   All I can remember is that there was an alien, and there was a movie star or actress or famous makeup artist on the ship traveling with another woman. By the end of the book the murderer was the woman the actress was traveling with who forced her to use her makeup skills to disguise her, and she was really some kind of alien.