I run Ubuntu from the USB drive, and select trial mode, because I do not want to install on the computer, just use it as a portable system on different computers that I have.  The problem I have, when I turn off the computer, all the settings I have selected and the applications I have installed are deleted, because they are saved in RAM rather than USB  I ask how can I do that they will be saved on the USB and will not be deleted  Would appreciate help,  Excuse me for using translation
I'd like to have Ubuntu installed on a USB stick, that I could plug in (almost) any computer and boot from it, and that I could use (almost) normally, as if it was installed on that computer. I'd also like to have a data partition on it that could be used by (almost) any computer, mostly to store some portable apps, just in case.    I've been told that if I installed Ubuntu in BIOS mode, I wouldn't be able to boot from a computer in UEFI mode, and vice versa.  Since I'd like to be able to boot on any computer, it's a big problem.  What can I do to be able to boot on computers in BIOS or UEFI modes in my case?  I've been searching for solutions but most of them are for specific needs that are different than mine, so it's difficult to extract the minimum requirements from those solutions to apply them to my problem.  Is there a simple, "clean" and quite generic solution to this problem?  I'd appreciate some explainations about the reasons why a specific solution is good or a specific step is needed.    My current setup:   USB stick:  OS: Xubuntu 16.04 i386 installation: full install (from a Live USB built with Rufus) drivers: none proprietary file systems:    partition table:    2: , /boot/efi, 128 Mio, FAT32, [boot,esp] 3: , 128 Mio, HFS+ 4: , 2 Mio, [bios_grub] 5: swap, 512 Mio 6: , /, 24 Gio, ext4, defaults,errors=remount-ro,lazytime,commit=60 1: , /media/data, ~3.6 Gio, FAT32, defaults,lazytime,check=strict  RAM:   /tmp, tmpfs, defaults,nosuid,nodev,noexec,mode=1777   swap:    vm.swappiness=5 swap partition: 512 Mio, for emergency zRAM swap files:    /var/swap/hib.swp: same size as RAM, for hibernation, generated by a script at startup /var/swap/opt.swp: if needed, generated by a script   overprovisioning: ~5.6%   built-in: ~1.2 Gio (apparently) added: 512 Mio  scheduler: deadline
Environment for two columns with lstlistings In order to reduce copy-pasting, I want to create an environment that will produce a two-column table with headers and two listings in different languages, like below:  \begin{tabular}{l l} Python &amp; Haskell \\ \hline \\ \lstset{language=Python} \begin{lstlisting} A \end{lstlisting} &amp; \lstset{language=Haskell} \begin{lstlisting} B \end{lstlisting} \end{tabular}   I want to use it like below, hiding everything but code:  \begin{comparison} A \vs B \end{comparison}   So far I tried making two new environments (instead of a \vs command inside) with \lstnewenvironment, where first environment had \tabularx command and second \endtabularx. I also tried creating normal \newenvironment for this tabular, &amp; for \vs command and manually inserting \begin{lstlistings} and \end{lstlistings} with code, but it stopped compiling when I put lstlistings inside.  How can I create such an environment?  EDIT: The most compact version I've came up with until now is  \newenvironment{comparison} {\begin{parcolumns}[nofirstindent,distance=0pt,colwidths={1=0.35\textwidth}]{2}} {\end{parcolumns}}  \lstnewenvironment{python} {Python \lstset{language=Python,frame=t}} {}  \lstnewenvironment{haskell} {Haskell \lstset{language=Haskell,frame=t}} {}   which is used like that:  \begin{comparison} \colchunk{ \begin{python} A \end{python} } \colchunk{ \begin{haskell} B \end{haskell} } \end{comparison}   I'm still unable to hide \colchunk{} within python or haskell environments. How can I SSH with a remote server so I can browse files and edit them? I have a username and password to use. multiple Open Drain UART over long distance I have 9 microcontrollers  and I have connected the RX and TX lines of 8 of them in parallel. My configuration is in master-slave. The master microcontroller send data to one of the 8 RX lines but only one of them can respond at a time. The cable length is about 3 to 5 metres between each node.  I have two questions. My test was done with 2 slaves instead of 8. UART at 9600bps.  If I setup the TX lines of the slaves as Open Drain it works fine, but the signal doesn't have steep ramps. I thought this happens due to Pull-up resistors. And I also think that is going to be better with 8 slaves on the bus, right?  Why doesn't that topology work if the TX lines of the slaves are not Open Drain?  I managed to make it work by disabling the transmit of the UART in all of them except one, and it worked fine. I had two slaves, so I disabled the one and left the other. Also I noticed that the edges of the signal was sharper. Why are they sharper in that case?  Regarding resistors: The value of the resistors for both RX and TX lines are 2.7KΩ. However the Open Drain topology would parallel the internal pull-up resistors. According to the datasheet that resistor is about 20KΩ at minimum. So, using a 2.7KΩ in the output would give us a total resistance of 2.52KΩ (20+2.7)/9. And the Open Drain would make a voltage divider 2.52KΩ + 2.7KΩ (Schematic 2). Which means with 8 slaves and Open Drain topology the signal will not go lower than 1V which is the threshold of the low level. Is that correct?  Wouldn't it be better to disable all the internal pull up resistors and place two (let's say: 4.7KΩ) only at the master side?  Distance: What is the maximum baud rate for such distance? I'm a little worried about the signal integrity. The test was done with 9600bps but I didn't notice any significant difference in 4800bps. The distortion of the signal didn't have a difference.  Voltage values are 3.3V for the UART bus.  Schematic 1. (all resistors are 2.7KΩ)        &ndash; Schematic created using   Schematic 2. (U4, U5, U6, U7, and U8 are omitted for simplicity).          EDIT: Thank you all very much about your answers so far. I wanted to point out that this is a question about UART only. I am not looking for alternative solutions. I'm just trying to find some answers about the above implementation.  EDIT2: Thank you very much for your answers! I ended up modifying a little my schematic. I disabled the internal pullup resistors of the microcontrollers and I placed external ones at the master's board. Their value would be around 1 KOhm to 3 KOhm. I have to do some tests more to decide the final value. I also replaced all series resistors with 130 Ohm.   I tested 5 slaves over 20 metre cable (with pullup 3 KOhm and 130 Ohm series resistors) and it worked fine.   Would it be better to add open drain/open collector line drivers on every TX lines? How do I install .run files? My PC has both Ubuntu and Windows 7 installed. I have installed all my drivers in Windows like Nvidia graphics, motherboard etc. Shall I install them in Ubuntu too?  I looked on the web for my Nvidia drivers and I have found a .run file. How could I install it on my Ubuntu? How can I selectively disable paste blockers Get rid of the question ban on Meta; suspend actively harmful users manually appears to have been question banned because of two unpopular Meta suggestions. (He says so in )  Look at the two contributions that appear to have gotten him banned. Like those of many others, they may not be of perfect quality, but they are not actively harmful to the site, either. As it stands, you can get question blocked on Meta simply for asking questions that aren't popular with the Meta crowd.  Why does the team insist on keeping the question ban active on Meta?  Why can't real problem users be dealt with through manual moderator action? Don't tell me it's a problem of scale; as far as I can see, actually toxic users are very rare on Meta.  People will frequently complain that Meta actively discourages the expression of unpopular viewpoints and suggestions. With the threat of question bans in place, I find those complaints difficult to refute. I hate that. I have a laptop with a full keyboard (it has numpad), but the laptop is not that big, and because of that the keys are relatively small, which means I am constantly finding myself pressing keys accidentally on the numpad part.  Is there a way to disable specific keys that I simply don't want? Is it possible to switch from one area of graduate study to another in US universities? For example, suppose someone has enrolled in a computer science phd program. Can he switch over to math(or physics) phd program in the same school later?(or say from applied mathematics to pure mathematics?)  What are the steps for doing for doing that? Placing point over pixel with maximum value falling in grid overlay using QGIS Is there any meaningful distinction between:  class A(object):     foo = 5   # some default value   vs.  class B(object):     def __init__(self, foo=5):         self.foo = foo   If you're creating a lot of instances, is there any difference in performance or space requirements for the two styles? When you read the code, do you consider the meaning of the two styles to be significantly different? What do 'real', 'user' and 'sys' mean in the output of time(1)? $ time foo real        0m0.003s user        0m0.000s sys         0m0.004s $   What do 'real', 'user' and 'sys' mean in the output of time?  Which one is meaningful when benchmarking my app? What are the benefits of running chef-server instead of chef-solo? I am looking at automated deployment solutions for my team and have been playing with Chef for the past few days. I've been able to get a simple web app up an running from a base Red Hat VM using chef-solo.  Our end goal is to use Chef (or another system) to automatically deploy application topologies to the cloud as we run builds. Our process would basically run like this:   Our web app code, dependencies, and chef cookbooks are stored in SCM A build is executed and creates a single package for images to acquire and test against The build engine then deploys new cloud images that run a chef client to get packages installed. The images acquire the cookbooks from SCM or the Chef server and install everything to get up and running   What are the benefits and/or use cases for getting a Chef Server running?  Are there any major benefits to have a Chef Server hold and acquire the cookbooks from SCM vs. using chef-solo and having a script that will pull the cookbooks from SCM? Encouraging software publishers to use StackExchange as support mechanism Whenever I deal with an application publisher's custom support mechanism because I can't see any evidence of activity on StackExchange, I always wish they'd just migrate to StackExchange, particularly when I get a prompt response from them. What a waste, I think, that my question and answer weren't captured on SE.  In cases where there is some activity for the application on SE, I'll post my question there and, if I get no response, reference the SE question in my email follow-up. In the case of , that had a happy ending where the support person posted the answer to the SE site at the same time they emailed me.  My related meta questions are:   Are there any obvious downsides to publishers effectively "giving up" their custom support mechanisms, or at least their custom forum, in favor of the appropriate SE site? Are there any obvious downsides to SE for publishers making this transition? Is SE staff engaged in any systematic marketing efforts to get publishers to make this transition? Is there any SE documentation which lists the advantages of publishers making this transition? Benefits & Practicality of Virtual Machines I have been living under a rock for the past 5 - 8 years, and am just now getting up to speed with virtualization, virtual machines and platforms like VMware or VirtualBox.  I think I am starting to get them, but there are two concepts about VMs that I'm just choking on for some reason; one has to do with their intrinsic benefit to the enterprise, and the other has to do with their practicality when being used.  So I understand that you can have multiple VMs running on the same physical machine, all doing their own "thing" as if they were separate machines. So let's say I want to make a nice little virtual network of servers in my home office so I can have a big sandbox to play inside of for all my projects. I set up 2 physical machines as servers, and on each of them I have, say, 4 virtual machines running (1 might be an app server, another might be a RDBMS, another might be a message broker, etc.).   Besides saving me money (as I only have to provide 2 physical machines instead of buying 8 servers), what instrinsic benefit/purpose do these VMs serve here? I don't care how clever virtual machines are, if my computer only has 8GB of RAM, and I have 4 VMs running on it, those VMs only get 8GB of RAM to share between them. Putting 4 VMs on my server doesn't endow it with 4 times that amount of RAM! So, as far as I see it, VMs save you money on hardware, but just end up bogging down that hardware as you have multiple machines competing over the same pool of resources. What am I missing here? Can VMs communicate with each other over your network using high-level protocols like TCP/IP, HTTP, FTP, etc.? Otherwise, it just doesn't make sense to implement all these VMs if you have to feed them separate and independent chunks of data/requests to process. I have an issue with my website: Google isn’t using my meta description, instead it’s using the content of the web page and I’m really confused.  Reason I’m confused is because I have checked and I don’t have duplicate page titles, description nor keywords, neither do I have any robots.txt for my website. My page title, description and keyword is unique, and page description is about 150 characters.  I have my site in Google Webmaster Tools and I checked for errors, but found none.  So I really don’t know why Google Search isn’t using my meta description. For example, on Debian or Ubuntu, which package has the /sbin/shutdown command in it? I want to read the source of that command (and possibly modify it to report notification on desktop) and I didn't know which package source to download. UnboundLocalError on local variable when reassigned after first use The following code works as expected in both Python 2.5 and 3.0:  a, b, c = (1, 2, 3)  print(a, b, c)  def test():     print(a)     print(b)     print(c)    # (A)     #c+=1       # (B) test()   However, when I uncomment line (B), I get an UnboundLocalError: 'c' not assigned at line (A). The values of a and b are printed correctly. This has me completely baffled for two reasons:   Why is there a runtime error thrown at line (A) because of a later statement on line (B)? Why are variables a and b printed as expected, while c raises an error?   The only explanation I can come up with is that a local variable c is created by the assignment c+=1, which takes precedent over the "global" variable c even before the local variable is created. Of course, it doesn't make sense for a variable to "steal" scope before it exists.  Could someone please explain this behavior? Windows 8 hibernation option missing from power options Windows 8 Professional 32-bit running on Laptop. And the Hibernation option is missing from the Power Options in the System Settings. Even after I enable hidden power features by giving admin privileges.  How can I fix this?    Also the option to enable hibernation is missing from the advanced power plan options.      SOLUTION UPDATE:  Thanks to  I have found that you need to enable hibernation using a command prompt.   Get to the Start menu, type 'CMD' this will begin the search. Press the CTRL+SHIFT+ENTER to start the command prompt with administrative privileges. Type powercfg -h on and press enter Control Android with broken screen from PC My rooted Galaxy Nexus has a broken screen. How can I use my PC (ie, via ADB) to control the phone?  androidscreencast would be the ideal solution, but its keyboard/mouse control feature does not work in Jelly Bean. Perhaps someone knows why and we can patch the code? (see: )  Installing a VNC server is another, but for the love of me I can't get it to work. Eg, using Droid VNC Server, I install the apk, and am supposed to execute /data/data/org.onaips.vnc/files/androidvncserver but there is no files directory inside org.onaips.vnc (instructions from here: ). VMLite is another VNC server that can be started with a special Windows utility (and doesn't need root!) but it's not OSS so I can't get the apk in order to install (Google Play is not pushing apps to my phone prob because I disabled some service--let me know if I can force Google Play to update itself from ADB or install the app). fastdroid-vnc is a binary (not apk) and it runs fine via shell, but something is broken and it shows nothing.  What are my options? Let's make this a community wiki, to help anyone who's broken their screen! JQuery to load Javascript file dynamically