If I understand well, you want your Ubuntu 18.04 PC to act like a router for the remaining 3 PCs.

To do it right, you ought to have two ethernet RJ-45 sockets on your Ubuntu box and a small network switch.

Your best option is to configure NAT via iptables and give DHCP addresses to 3 PCs.

See https://www.howtoforge.com/nat_iptables and
https://linuxconfig.org/what-is-dhcp-and-how-to-configure-dhcp-server-in-linux

Alternatively, you can use static addresses for 3 PCs, but they have to be on a separate network for routing to work ...

NAT can be provided with this simple GPL'ed script

http://domac.alu.hr/~mtodorov/adm/iptables-nat

You need to configure the second interface in Ubuntu PC for your second LAN card. Typically these will be eth0 as default which connects to ISP's router-modem and eth1 which connects to your 3 PCs via your 8 port hub. eth0 will have the address assigned from your ISP's router-modem and it will typically look like 192.168.1.2/24 or something like that. You need to know how to configure eth1 interface for the internal network with 8 port hub and 3 PCs. This belongs to /etc/network/interfaces . (Or is it netplan in Ubuntu 18.04.02 LTS?) You will want your 3 PCs on a different network, say 192.168.2.0/24 . Netmask will be 255.255.255.0 , for both networks. Assign addresses like 192.168.2.2, 192.168.2.3 and 192.168.2.4 to your PCs. This choice simplifies as you don't have to configure DHCP. Then NAT and IP forwarding on Ubuntu PC will do the magic. The script which I have provided works well in an environment with two networks. I don't know your level of knowledge, so I tried to simplify it as good as it is possible.

3 PCs connected to 8 port hub must have Ubuntu PC configured as their default gateway.

Ubuntu PC will receive DHCP (dynamic) address from ISP, and will offer static addresses to 3 PCs on the hub. But, alternatively, you can configure dhcpd on Ubuntu to give dynamic addresses to 3 PCs, too.

netplan configuring of networks is somewhat new to me. I used to setup /etc/network/interfaces which is somewhat simpler.

The problem is that Ubuntu 18.04 LTS, unlike previous versions like 16.04 LTS, uses /etc/netplan/*.yaml configuration instead of /etc/network/interfaces ...

You can try to understand netplan configuration by looking at these examples. Good luck there!

https://netplan.io/examples


In KDE 4.11.2 saucy with both nvidia and nouveau drivers I have strange artefacts

Try disabling Blur in System Settings / Desktop Effects / All Effects in the Appearance section. It fixed it for me. Hope it works for you as well.

I use nvidia drivers 331.20, mint 13 (based on precise LTS) with KDE 4.12.0.


This one is pretty easy, but I'm going to assume that you don't already know about aliases.
Aliases are ways to turn your own customized commands into actual functioning commands. They come in pretty handy.
Open your home directory and create a plain text file called .bash_aliases. Go ahead and save it - but leave it open in your editor.
Now, think of a word or phrase you'd like to use to execute your script. In my case, I used test.
In my Documents directory, I made a file called test.sh and inside it contains:
echo "This is a test script!"

NOTE You'll want to not forget to make your script executable. You can do that with chmod +x or in the GUI with a right click/properties menu option.
Now, back in your .bash_aliases file, you'll want to add it as a command. In my case, it looks like this:
alias test="./Documents/test.sh"

NOTE In all those cases, the "." and capitalization are essential. It's Case Sensitive.
Now, you need to tell your system to look for (and reload any new) aliases. This is done in the terminal with the following:
source ~/.bash_aliases

After all that, I can do this:
$ test
This is a test script

As you can see, you're telling it where the aliases are and you're reloading them. Any time you add new aliases, you'll need to run that to make them usable.
EDIT: While the above method will work, it will only work when the terminal is opened in your /home/user/ directory. That's fine and that's the default place most terminals open, but not all terminal work is done in that directory.
The answer is this:
$HOME/Documents/test.sh

Now, no matter what directory you're in, you can type test.sh and it will work. This doesn't need elevated permissions and the script can then only operate with your user permissions or whatever additional permissions you grant at the time of execution.
If I had to pick, I'd go with this method - the one where you use the user's home directory variable of $HOME (again, case sensitive) as a generic user can set it up, configure it, use it, etc... It doesn't require root access or any extra permissions.
As mentioned elsewhere in this answer, there are a variety of ways to accomplish this. Pick the one that best suits your needs and requires the least permissions.
Method #2:
I got bored and decided to add another way.
After you make your script executable, you can move your script to usr/bin and just make it a command. In my case, I used a GUI.
In the terminal, I entered:
sudo pcmanfm

Then, I just copied the test.sh to usr/bin - and it retained the executable permissions I'd applied before.
At this point, I could just use test.sh and it would work.
I wasn't happy with that, so I renamed it to just plain test1 and removed the .sh from the file name. Linux doesn't really care too much about the extension names. I couldn't name it test as there was already a test in the usr/bin directory. So, test1 is what I named it. Obviously, you can name it anything you want, so long as it doesn't conflict with other file names.
Now, from the terminal, it works just like this:
$ test1
This is a test script

As you can see, there are a variety of ways to do this. I'm most fond of the alias method, as it doesn't require any elevated permissions and I'm a big fan of the 'least permissions' method.


Cannot send mail from command line, sasl authentication error

You need to 'allow less secure apps', the settings are located within Google account settings—to enable the settings please visit this link https://myaccount.google.com/lesssecureapps.

Then, try sending email again, it should work, you can also check the recent mail log by typing:

tail -f /var/log/mail.log

Usually the email success message goes along with this line.

hostname postfix/smtp[2875]: F5182534OUA: to=<john@mail.com>, relay=smtp.gmail.com[74.125.130.109]:587, delay=2.8, delays=0.07/0/1.6/1.1, dsn=2.0.0, status=sent

If you feel uneasy allowing 'less secure apps', you can use app password—in which you can generate standalone password for postfix itself. But it requires settings up 2 step verification, refer to this link for more details.

https://www.google.com/landing/2step/
https://www.lifewire.com/get-a-password-to-access-gmail-by-pop-imap-2-1171882


Using sed to add text to a file before and after word

You can also process your list of words with the following perl command:

$ perl -ne 's/\s*$//; print "egrep -wi \047\|${_}\.\.nn\047 stats_all.txt > ${_}_frekvens.txt\n"' word_file.txt

Note that I'm using \047 to avoid escaping ' (single quote).

With a dummy word_file.txt:

foo
bar

The output is:

egrep -wi '\|foo\.\.nn' stats_all.txt > foo_frekvens.txt
egrep -wi '\|bar\.\.nn' stats_all.txt > bar_frekvens.txt


I have the exact same issue, right now the workaround is to suspend/resume or blindly open terminal through Ctrl+Alt+T and type xset dpms force off then just move the mouse and screen should be back.

I still haven't been able to find a real solution.


Alternatively You could download the "GnomeTweakTool" and deactivate it under Mouse & Keyboard > Click Emulation


ChromeVox voices list empty on Ubuntu 18.04

Looks like you have to compile the Chrome OS version of Chrome: "If you‘re building Chrome from source and running it on desktop Linux, speech and braille won’t be included by default."
https://chromium.googlesource.com/chromium/src/+/lkgr/docs/accessibility/chromevox_on_desktop_linux.md


Create Separate Firefox Audio Recordings Simultaneously

Using pavucontrol "playing"  tab  , you can unlock channel, then set   each Firefox instance  to a different channel (one left , one right) .
Then set the ffmpeg option -ac  to record only left or only right :
ffmpeg -f pulse -ac 1 -i default testleft.mp4
ffmpeg -f pulse -ac 2 -i default testright.mp4
More flexible audio routing can be done by jackd but Firefox needs pulseaudio.
May be you can use this special Firefox with jackd support.


problem with live lubuntu application installation

When you boot from a Live CD / DVD, the operating system is copied from the CD / DVD into a ramdisk, and every modification done to the currently running system is applied to the ramdisk. A ramdisk (per its scope) is going to lose all the informations contained in it upon shutdown (to be precise upon power cut; it also actually takes a while for the RAM capacitors to discharge, but that's another story). This means that any modification, pretty much like the type of memory in which gets stored, is volatile.

If you want to boot from a Live CD / DVD with some applications ready to be used, one solution is to customize a Live CD / DVD, altough this still won't allow you to store the applications' settings or any file.

If you want to store those, the only feasible solution is the installation of the operating system on a writable drive (such as on an internal hard disk or on a USB drive of any mean)


APTonCD may help you. Check my related answer about a similar question:

Its a tool that scans your APT-installed packages and build a list for you. You can then manually select/deselect the ones you want, save the list, and it can even download/use cache to save selected packages in a CD/folder (for an offline automatic install of currently installed apps)

I know, this is not exactly what you want. But you could customize your CD install to use the .DEB files folder created by APTonCD as an additional APT-GET source list (like an offline PPA) by creating a customized entry in the /etc/apt/sources.list file.

And then just create a simple post-install script to install all the packages there.

So, if your "remastered install with pre-installed additional packages" is not working, maybe this "original install with post-install trigger to apt-get packages in a folder" approach may work.


You can go to /usr/share/themes/YOUR-THEME to tweak the CSS. The main file for this is gtkrc often located in the gtk-2.0 directory. Be sure to read the comments in the document. Here is an example of an edit I made when the background color, bg_color, in the theme Greybird was a little too gray for me (/usr/share/themes/Greybird/gtk-2.0/gtkrc).

# gtk-color-scheme  = "bg_color:#CECECE\nselected_bg_color:#398ee7\nbase_color:#fcfcfc" # Background, base.
gtk-color-scheme    = "bg_color:#EEEEEE\nselected_bg_color:#C3D4AA\nbase_color:#fcfcfc" # Background, base.

I commented out the original so there would still be a record if I wanted to go back. You will need to log out or change your theme and return to it again for the changes to be applied. Often gtkrc will have a gtk-color-scheme section at the top of the file. This is the overall color scheme.

I recommend going to Window Manager > Style tab to try different options. Also customize in Appearance > Style and Icons tabs. Playing with those three options can offer a lot of possibilities. I really like setting a custom color. On Xubuntu 14.04, I have Daloa as the Window Manager, Orion as my theme (Style tab in Appearance), and elementary Xfce darker as my Icons. Then in Theme Configuration, gtk-theme-config, I have custom colors set. With this setup I have nice green accents throughout my system.

If you have Xfce 4.12, Orion is not installed there, but there I use Greybird theme. (This is on my Fedora Xfce install.) Greybird also does a nice job of populating my theme color throughout the system.

Sometimes a theme may not cover every aspect of every program. In these cases the default theme would be used. In Xubuntu 14.04 this is Raleigh. Only certain themes have an accompanying Window Manager style. If they do have it, there will be an xfwm directory in the theme's directory with a themerc file:cd /usr/share/themes && find . -type d -name "xfwm4" -print | sort

I recently installed Numix on Fedora Xfce (particularly for the icons). It is a nice looking theme and is available for Xubuntu. http://www.webupd8.org/2013/08/new-ppa-for-numix-gtk-and-icon-themes.html

To answer the part about using one part of a theme in another, I wanted to make my Xfce panel have a text shadow with using Orion. I noted that I liked Greybird's text shadow on its panel. Instead of combing through the CSS in Orion to see what to change or add, I backed up /usr/share/themes/Orion/gtk-2.0/apps/panel.rc. Then I just replaced this file with /usr/share/themes/Greybird/gtk-2.0/apps/xfce-panel.rc. Worked just fine.


Is it safe to browse the web with Firefox during Ubuntu install?

Should be fine.  Might cause the install to take a little longer, but probably nothing serious, especially if it's just random browsing and not, for example, playing big heavy Flash games at a site like Kongregate (assuming you even have Flash available in the installer environment, which I don't know the answer to off the top of my head).


How to fix out the error dpkg: error processing colord (--configure):

This fixes it for me:

sudo delgroup scanner
sudo apt-get install colord

That did it for me.  Below were the diagnostic steps I took.

if you look at /var/lib/dpkg/info/colord.postinst - and add a set -x at the top and run it manually (/var/lib/dpkg/info/colord.postinst configure) - it will not get past adding the scanner, and if you get rid of --quiet, it says:

sudo addgroup --system scanner
addgroup: The group `scanner' already exists and is not a system group. Exiting.


Icon of running firefox in the specific profile in gnome

For the panel, you need this:

mkdir ~/.icons
mkdir ~/.icons/<your_icon_theme>
mkdir ~/.icons/<your_icon_theme>/32x32
mkdir ~/.icons/<your_icon_theme>/22x22
mkdir ~/.icons/<your_icon_theme>/16x16
mkdir ~/.icons/<your_icon_theme>/22x22/status
mkdir ~/.icons/<your_icon_theme>/16x16/status

Place your icon in

~/.icons/<your_icon_theme>/32x32/status
~/.icons/<your_icon_theme>/22x22/status
~/.icons/<your_icon_theme>/16x16/status

The name of the image file must match the name that the image had in

/usr/share/icons/<your_icon_theme>/32x32/status
/usr/share/icons/<your_icon_theme>/22x22/status
/usr/share/icons/<your_icon_theme>/16x16/status.

Then restart your GNOME session.

For the launcher, you need this:

Create your custom desktop file for Firefox. The files in ~/.local/share/applications/ take precedence over the system directory /usr/share/applications/ if they have the same name.

cp /usr/share/applications/firefox.desktop ~/.local/share/applications/

Open the file with:

nano ~/.local/share/applications/firefox.desktop

Find the line that begins with Icon= and replace the value firefox with your prefered icon path, eg:

Icon=<my_firefox_icon_path>

If you want to use another image from your icon theme, then use the name of the file without extension, eg:

Icon=mozilla-firefox

The images of your icon theme are in this directory

/usr/share/icons/<your_icon_theme>


Thinkpad T430 with dual DVI and Bumblebee. Detects the VGA port on my dock but not the DVI

It's possible that some of the ports (i.e. the dvi ports) are connected directly to the nvidia graphics card rather than the integrated intel card that runs the thinkpad display. This was the case with my W530 - see my blog post here: http://zachstechnotes.blogspot.com/2012/01/tri-head-display-on-linux-thinkpad-w520.html

The primary function of Bumblebee is to render graphics on the nvidia card and send that image to the intel card to show on your thinkpad display. In order to use the digital outputs, you'll need to send the data to the external monitor through the nvidia card. There are various workarounds to accomplish this, however they aren't super straightforward. If you want to move forward with one of those workarounds, leave a comment and I can expand my answer and point you in the right direction.


Error when trying to get movies off my Camera

Shotwell 0.8 will support video, including importing them off cameras: http://trac.yorba.org/ticket/855

We're considering adding audio support in a future release: http://trac.yorba.org/ticket/2920


Some ways to start the Software Center from the desktop
1. From the Launcher

2. From the Dash

Click the Ubuntu icon on the top left or press the Windows/Super key and type: software:

3. How to bring it back to the launcher
If Software Center is not on your launcher as shown in section 1 above, just start it, and then right-click on its icon in the launcher and click on "Lock to Launcher":


How to install mysql and other software to ubuntu12.04?

Welcome To The World Of Linux

First of all, Please try to reinstall your os to the latest versionif possible as there are plenty of patches updated. This may be the cause to your problem.

Next, update the current os with all the packages.

Media/ Codecs

sudo apt-get install ubuntu-restricted-extras

After following the above steps, try following the steps for MySQL installation
May be that the version is outdated or not supported anymore( Just a thought)


Installer tries to resize my recovery partition instead of the normal partition when installing alongside Windows 7

Use tuxboot or unetbootin to create a bootable usb of gparted live or just use any ubuntu livecd installer and boot into it and select try ubuntu option,now use gparted partition editor to extend or modify the  partition on your system,the thing is that for any operation like extending etc have to be performed when the volume is offline.

you can download gparted live here.there are also instructions to make a live cd/usb over there.

You can use easyBCD software to dual boot,please follow this guide

Most of the times it will work,sometimes this may not work.In that case you can follow this article.The second method is somewhat complex but it works for sure,I used both methods.


How do I install ubuntu-desktop and compiz from root terminal?

With root access, you should be able to reinstall Ubuntu Desktop with

apt-get install ubuntu-desktop --reinstall

As for getting compiz reinstalled, you might check out this thread on UbuntuForums. Though it refers to reinstalling under Lucid, the principle should be the same.


Should I allow packages to be downgraded by synaptic?

Perform the following commands in a terminal, in order to update the package sources:

sudo apt-get update

Then run the installation of dkpg-dev again:

sudo apt-get install dkpg-dev

Based on your sources.list and an empty /etc/apt/sources.list.d, accepting the downgrade should pose no problem.


Is there a way to stack images side by side with imagemagick?

ok i figured it out.
you can do this:
$convert a.gif a.png
this will give you a series of images a-1.png, a-2.png, a-n.png .... and so on.
then, you can do this:
convert +append a-*.png out.png

This will give you a horizontal sprite sheet instead of a vertical one, in out.png.  A single line of code my be possible, I have like 0 extra time to figure it out though.


It is possible to do that.  HOWEVER: If the drive is actually failing, then you will eventually lose everything you put on it.  If it's just the boot sector that is bad, then it should work fine.  Use 'Disks' inside Ubuntu to format it with an EXT4 filesystem (or something else if you like) and it will show up just like a thumb drive.  You can also use this drive for backups.


Yes, same problem here. More generally, the old System Settings icon is missing in 11.10. To access your settings (and change speaker volume):

Right-click your username in the upper-right corner of your screen, on the toolbar.
If you do not see "System Settings" on the menu, try right-clicking directly to the right of your username on the toolbar.
Select "System Settings". Right-click on "Sound" and change your sound settings as needed.

There is an "Other" tab with more settings--I'm posting the link to a blog with more information about how to access this tab. You will need to 'un-hide' it under "Edit Menus" in order to use it:

http://ubuntugenius.wordpress.com/2011/10/17/ubuntu-11-10-upgrade-missing-your-system-menu-preferences-administration-launchers/


macbook 11,5 Wifi [14e4:43ba] doesn't work on 14.04

You need to uninstall wl driver by

sudo apt-get purge bcmwl-kernel-source

Copy brcmfmac43602-pcie.bin to /lib/firmware/brcm.

But if you updated your system, this file should be already there in 14.04.

Reboot and make sure that command lspci -knn | grep Net -A2 gives output

Kernel driver in use: brcmfmac


Bluetooth doesn't working Ubuntu 14.04 LTS

from the output you provided here, your Bluetooth device is:

  Bus 002 Device 004: ID 04ca:300b Lite-On Technology Corp.

If you search with 04ca:300b on launchpad.net, you could find several expired bug report for this:

Bluetooth 04ca 300b not working Ubuntu 12.04
[Acer Aspire V5-132] Bluetooth not working

And unfortunately, it's not working in Precice and Trusty

I will suggest you to open a bug on launchpad.net with ubuntu-bug linux command in your terminal to get it fixed in future Ubuntu releases.

For more detail regrading filing bugs, you could follow this article: ReportingBugs, or this guide: how-do-i-report-a-bug

Not an easy task, but that's how we make it better, good luck!


The only way to easily switch between windows and Ubuntu OS's was by running Ubuntu on virtual machine softwares like VMware,virtualbox,etc.


I'd like to offer some advice rather than gift wrapping an answer. Funny thing about computers. They're built by humans to be logical and sensible. They aren't designed to be tricky, but they are complex, and the documentation, when there is documentation at all, never covers all possible contingencies.

Forgive me for making assumptions, but it seems to me that you are in possession of a small puzzle, and all the pieces to solve it. Try different combinations. Re-read the documentation. Type

man mount

in the terminal for a worthy guide to all things mount. Don't be (too) afraid to guess wrong and break something. This is the pattern with every computing problem you will ever encounter.

I work with a recent college graduate who can barely wipe his nose unaided. He has to run every tiny piece of every encountered problem past other staff before he can act. Some might be flattered to guide him. Others might resent that he values his own time more highly than the time of his co-workers. If you're planning a career in computers, you can hope to team up with the flattered, but you're certain to run across the resentful. Take another stab at it.

Then again maybe you're an English major who just wants to be done with his homework. If so I apologise for the unwarranted career advice. Still, take another stab at it.


Yes, tail outputs lines appended to all the files given on the command line:

tail -F sqlLogs.log perflogs.log | egrep '(sql-time|exec-time)'


For removing the installed deb file, just use:

sudo dpkg -P cudawhateverdebyouinstalled

For installing to another location, I used:

  dpkg-deb --extract yourcuda.deb directory-for-install

Then alter your PATH and LD_LIBRARY_PATH as recommended to add the new bin and lib locations from your install location.  Test things out by compiling/running the cudasamples.


How to change how files are sorted in different folders in Dolphin?

As first step, you may have to go to:

Control > Dolphin preferences > General > Behaviour > View

and mark

Remember properties for each folder

Then go to:

Control > Adjust view properties

In the window that pops up, adjust the parameters as you want and then select:

Apply to: Current folder

or

Apply to: Current folder and sub-folders


You are likely to receive a personalized response soon ONLY if:

You are registered at Launchpad.net with your proper contact information.
You filed a proper bug report (not merely sending crash data).
The bug report is complete. A developer can reliably duplicate the problem in their test environment right now.
The bug report is prioritized as CRITICAL or HIGH.

Very few bugs meet this threshold.
Your issue looks unlikely to meet this threshold, since your question not provided a lot of the basic information necessary to reproduce the problem in a test environment. Legions of volunteer testers tried upgrading from 20.04. Some filed bug reports. The developers fixed many of the reported problems that they could reliably reproduce.
Advice: Backup your data, and clean-install Ubuntu 21.04


I was trying to run this thing on Makefile, so I changed the Makefile so that it runs /path/to/the/absolute/location/spark-submit instead of just spark-submit and now it just works. Who could have guessed.


I suggest you don't do that. Those instructions are showing you how to compile and install the software manually yourself. In Ubuntu you mostly install software from the package repositories.

Open "Software Center" from the dash (the Ubuntu logo at the top of the bar on the left) and search for valgrind in there. You'll then be able to install it and, after that's done, to use it.


You should boot from a LiveCD then do the following:

Mount your Ubuntu installation by clicking on the device's icon in the file manager.
Open a terminal and cd into the /usr/bin folder of that installation you mounted from above.
Run this command to give all users execute permissions

sudo chmod -R a+x .

Run this command to give all users read permissions

sudo chmod -R a+r .

Run this command to remove all users (except root's) write permissions

sudo chmod -R o-w .

Reboot and see if it works.


Nautilus - How to apply Zoom on the filenames? Not just on the thumbnails

You can try to edit the Nautilus source code to scale the font in the zoom like in Nautilus 3.4.

NOTE: In this example I'm running ubuntu 13.04 with nautilus (files) 3.6.3.
You can test this in a virtual machine to see if everything is OK.

First of all, I set the Nautilus Prefereces in "List View" as Default View and "200%" the zoom in List View Defaults.

By default the result with no scale font would be:

1) Make sure you have enable the Source code repository

Open the Ubuntu Software Center
In the Menu Bar choose Edit -> Software Sources. Click to enable "Source code repository".
Just in case I use the "Main Server" to Download.

Open a Terminal window and type:

sudo apt-get update

2) In the Terminal type the following to install the necessary packages.

sudo apt-get install build-essential quilt

3) Install build dependencies.

sudo apt-get build-dep nautilus

4) Create a folder to download the source code.

mkdir ~/Downloads/src
cd ~/Downloads/src

5) Download the source code & Export variables.

apt-get source nautilus
export QUILT_PATCHES=debian/patches
export EDITOR=gedit

6) Create the patch and Edit the source code.

cd nautilus-3.6.3/
quilt new my_custom_zoom.patch
quilt edit src/nautilus-list-view.c

After line 133 add:

static void   nautilus_list_view_scale_font_size                 (NautilusListView        *view,
                                                                  NautilusZoomLevel  new_level);

After line 2506 add:

static void
nautilus_list_view_scale_font_size (NautilusListView *view,
                    NautilusZoomLevel new_level)
{
    GList *l;
    static gboolean first_time = TRUE;
    static double pango_scale[7];
    int medium;
    int i;

    g_return_if_fail (new_level >= NAUTILUS_ZOOM_LEVEL_SMALLEST &&
              new_level <= NAUTILUS_ZOOM_LEVEL_LARGEST);

    if (first_time) {
        first_time = FALSE;
        medium = NAUTILUS_ZOOM_LEVEL_SMALLER;
        pango_scale[medium] = PANGO_SCALE_MEDIUM;
        for (i = medium; i > NAUTILUS_ZOOM_LEVEL_SMALLEST; i--) {
            pango_scale[i - 1] = (1 / 1.2) * pango_scale[i];
        }
        for (i = medium; i < NAUTILUS_ZOOM_LEVEL_LARGEST; i++) {
            pango_scale[i + 1] = 1.2 * pango_scale[i];
        }
    }

    g_object_set (G_OBJECT (view->details->file_name_cell),
              "scale", pango_scale[new_level],
              NULL);
    for (l = view->details->cells; l != NULL; l = l->next) {
        g_object_set (G_OBJECT (l->data),
                  "scale", pango_scale[new_level],
                  NULL);
    }
}

After line 2569 add:

/* Scale text. */
nautilus_list_view_scale_font_size (view, new_level);

Remove lines 3051 & 3052.

/* ensure that the zoom level is always set before settings up the tree view columns */
list_view->details->zoom_level = get_default_zoom_level ();

7) Build the deb packages.

quilt refresh
fakeroot dpkg-buildpackage

8) Install the deb packages.

cd ..
sudo dpkg -i *deb

9) Finally you can Logout and Login to see the changes.

Result:

NOTE: You can zoom in, zoom out with the Ctrl + Mouse Whell or with Ctrol++ & Ctrol+- keys.

Hope it helps.


Installing Windows after ubuntu on a separate HDD?

Installing Windows will overwrite the MBR anyway (had this problem some time ago). The way you can get it working, is to physically UNPLUG the drive with your Ubuntu, by completely removing it from your computer, then installing Windows on the other drive, and re-plugging the drive with Ubuntu.

This way you will be completely sure MBR will be okay, for Windows installer will have absolutely no access to the drive with Ubuntu, as it will be separated from your computer (but some people advice it is even safer too temporarily keep the unmounted drive in a separate room, just in case [not really, I'm just kidding]).

This way you will get both systems installed on separate drives. After re-plugging make sure to alter your BIOS setting - you want to start the boot from the Ubuntu drive, as that's where GRUB is. Note that on first boot you will (most probably) not have an option to boot Windows. To fix that, boot into your Ubuntu and run sudo update-grub, this should detect Windows and add it's entry to the boot menu.


Quick question: Will a fresh install Ubuntu detect my Raid-0?

First: Upgrade. 13.04 is out of support. Upgrade to 14.04 and you won't have to upgrade again until 2019 if you don't want to.

Secondly, you haven't said what sort of RAID this is.

FakeRAID (most onboard motherboard RAID controllers) can be detected by dmraid but this needs installing. This is documented and we have older questions about it too.
Windows software raid is something else completely. My Google Fu is lacking this morning but everything I find suggests it can't be read from Linux.
Real RAID controllers usually work but sometimes need drivers installed. This really depends on the controller.


How do I get a Canon Pixma MG 3150 working?

http://support-sg.canon-asia.com/contents/SG/EN/0100393702.html

try with this one! You have deb file inside. Just choos correct one and simply install


How can I use local .deb files in my pbuilder builds?

This can be done a few ways. As mentioned by adol, the Ubuntu wiki has a nice example of how to do this by creating a local repository with mini-dinstall and adding that to your pbuilder config. Dennis' answer about using dpkg-scanpackages works as well.

I've been doing this recently with apt-ftparchive. I like this approach since I find it very light weight. Here's annotated example of what I do:

# From my ~/.pbuilderrc file

# Location of the dir where you keep pbuilder hook scripts.
HOOKDIR="/home/andrew/.pbuilder-hooks"

# Path to your local repo to be used as a mirror written as apt source line.
OTHERMIRROR="deb file:///home/andrew/pbuilder/local_repo ./"

# Path to your local repo. This tells pbuilder to mount this directory so it is available in the chroot.
BINDMOUNTS="/home/andrew/pbuilder/local_repo"

# As we need to have the apt-ftparchive command, we need to insure this package is installed.
EXTRAPACKAGES="apt-utils"

You also need a pbuilder hook:

# From my ~/.pbuilder-hooks/D5update-local-repo file

# Path to the local repo.
LOCAL_REPO="/home/andrew/pbuilder/local_repo"

# Generate a Packages file.
(cd $LOCAL_REPO ; apt-ftparchive packages . > Packages)

# Update to include any new packages in the local repo.
apt-get update

Now all you have to do is drop the packages into your local repo and they will be available to pbuilder. If you are trying to chain build a string of dependencies you can make you pbuilder results directory as your local repo directory.

You can probably imagine other variations on this. For instance, you could use dput with a post_upload_command to generate the Packages file instead of using the hook.

This Debian wiki page could also be helpful.


First of all, since you're using Snapcraft 1.x make sure you're running Snappy Ubuntu Core 15.04. You need to declare your binaries in the snapcraft.yaml (example). Once you've done that, upon install the binary will be available in your $PATH so you can just run it like:

$ <snap name>.<binary name>

So for the example I linked above, that would be:

$ opencv-example.example

Note that this is the same for Snappy Ubuntu Core 16.04/Snapcraft 2.x, but the syntax to declare the binaries changed (same example, but for 16.04).


Follow these steps carefully.

sudo gedit /var/lib/dpkg/info/crossplatformui.postrm. This will open that file in gedit text editor with super-user privileges.
press Ctrl+F in gedit to search. Write in the search-box ztemtvcdromd and comment out those lines which contains the search string by placing # at the start of the line(s). If this process seems complicated then simply put exit 0 after the first line (which should contain #!/sbin/sh).
save the file /var/lib/dpkg/info/crossplatformui.postrm.
then try dpkg -r --force-remove-reinstreq  crossplatformui to uninstall the package.


Cannot log in with correct password after installing VirtualBox and Genymotion and editing /etc/profile

Open the terminal using CTRL + ALT + F1 (or whatever key works for you).
While in your home directory, type the command cat .xsession-errors.

This will give you the error that is causing the login screen loop. In my case it was an error in the /etc/profile that I had edited last night.


I cannot access my hard drive from ubuntu

DDRescue can make an image of the damaged hdd despite reading errors

In case of complete hardware failure, there is nothing to do else of an hardware intervention. In many cases, the electronic board of the hard-drive is failing, disks and other mechanical parts are ok. So, if you can find an identical drive, you can switch pcbs and have the hdd running again... But that is a bit tricky.

The software solution will be to make an image of the damaged hdd despite reading errors. DDRescue was made for this.
Once booted from USB Live Ubuntu, simply install -to ram- the required software, plug-in another external media and save on it an image of the failing hdd.

You have two options:
 - Text mode with gddrescue package
 - Graphical mode with ddrescue-gui package

1/ Graphical mode

# Graphical Mode:
# Boot with live usb
# Install DDRescue graphical
sudo add-apt-repository ppa:hamishmb/myppa
sudo apt-get update
sudo apt-get install ddrescue-gui

2/ Text mode

# Text mode:
# Boot with live usb
# Install gddrescue
sudo apt install gddrescue

Official documentation:
https://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html

Find some howtos on how to use ddrescue:
 - https://www.youtube.com/watch?v=6iiyREu4-wI
 - https://www.technibble.com/guide-using-ddrescue-recover-data/


How can I controll Brightness in Sony Vaio SVE151A11W?

the only way to change brightness is to use this command

sudo su

echo 150 > /sys/class/backlight/intel_backlight/brightness

all other solution does not work at the moment.
this is not my work around. i dont remember where i got this but it works and hats off to the person who gave this workaround :)

Using Ubuntu 13.10 64Bit Wubi on Lenovo Z570


Run in a terminal

sudo apt install --reinstall linux-firmware

/lib/firmware/radeon/PITCAIRN_pfp.bin is missing that used to be there.


Putting an arbitrary gtk.Widget into an appindicator.Indicator

The Application Indicator menu support is based on D-Bus menus, which are limited in what they support - they only support basic menu functionality, not more exotic things such as arbitrary widgets.

One significant roadblock to them ever supporting such things is the fact that the application indicator menu is rendered by a different process, the application indicator process, so your program doesn't have access to directly draw anything on it.  Overcoming this would require either supporting something like X-Embed in D-Bus menus or allowing all of GTK to work over D-Bus.


My solution: Launch Steam in "Big Picture" mode (click the controller icon in the top right), then wait for it to open. After it loads, press the "Super"/"Window" key (in between ctrl and alt) to show all open windows, then click & hold on Steam and drag it to the monitor you want to play on. When you launch the game, it will open on the same desktop/monitor.

I remember seeing an option to choose the output monitor at one point, but I just checked again and I cannot find it. That option may have been in the Windows Steam client...


Broken internet on restored Ubuntu VirtualBox VM

The network adapter inside VirtualBox under Network settings needs to be setup properly for other Guest machines....they all have different Network Interfaces.

Check syslog and your /etc/network/interfaces config.


Have you tried a manual format?
During the installation of Ubuntu 12.04, delete every partition except for the window's partition. (It will either be an NTFS or a FAT32 type.) Depending on your computer, add at least a 1GB SWAP-type partition and add the rest of the free space as an Ext4 and choose to mount it as "/". That way you will be starting from scratch and it will keep your XP install. For more information, look here: http://news.softpedia.com/news/Installing-Ubuntu-12-04-LTS-266201.shtml and look under 4: Something else (Advanced)
Do remember to be careful not to remove your partition containing XP.


Peaceful coexistance of Intel and Nviidia GLX

You might try to restore the original /usr/lib/xorg/modules/extensions/libglx.so from xserver-xorg-core . That's what I did in a similar situation. Here's how:

First confirm that it has indeed been replaced by the nvidia install:

debsums xserver-xorg-core | grep libglx.so

If it shows FAILED, it means that it has actually been replaced, and you could try to restore the original.
To restore the original, first find the .deb filename for your installed package:

apt-cache show xserver-xorg-core | grep Filename: | head -1

It should show something like this:

Filename: pool/main/x/xorg-server/xserver-xorg-core_1.7.6-2ubuntu7.12_i386.deb
                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Locate where you can download that file from, and download it. (Usually a Google search on the filename, marked with ^^^^^^ below, is enough.) Save it on /tmp.
Extract the needed file from the package:

cd /tmp
dpkg --fsys-tarfile xserver-xorg-core_1.7.6-2ubuntu7.12_i386.deb | tar xvf - ./usr/lib/xorg/modules/extensions/libglx.so

Rename the file you are about to replace (just in case you need it later):

mv /usr/lib/xorg/modules/extensions/libglx.so /usr/lib/xorg/modules/extensions/libglx.so.orig-20140914

Copy the original file to its correct place:

mv ./usr/lib/xorg/modules/extensions/libglx.so /usr/lib/xorg/modules/extensions/libglx.so

Restart your X (logging out and back in from my graphics session was enough here).
Run glxgears (or your preferred GLX program) to confirm everything is dandy now.

The above is tested and working on my oldie Ubuntu 10.04 desktop (no Unity for me), should work on your 12.04 install too if you follow the indicated procedure for finding out the .deb package name (which will be different than mine).


Why remount fixes the problem but not the fstab?

Remount doesn't fix the problem. It may even make the situation worse.

Here is what is happening:

Windows hibernates while keeping that partition mounted
Ubuntu boots, finds out that the partition hasn't been unmounted properly and mounts it read only. This is a safety feature and it is for your own good.
You remount it read/write and perhaps start writing to it.

What is not obvious:

1.a. Windows kept an in-memory cache of the filesystem state which said that (figuratively speaking) sector 789 is free

1.b. That in-memory cache has been stored in the hibernation file.

Ubuntu writes a new file to sector 789 - it is free after all.
You reboot to Windows and it loads its state from the hibernation file.
You create a new file
Windows uses sector 789 to store that new file - after all its cache says that this sector is free.
The file you created in Ubuntu (step 4) is now corrupted.

The proper way to solving this is to somehow unmount that partition in Windows before it hibernates and to auto-mount it again on startup.

How to do that and whether it is possible at all is beyond this forum.


My laptop boots with full screen brightness and full keyboard backlight

It works here. I've added
chmod a+w /sys/class/backlight/acpi_video0/brightness
to my rc.local and I can now do
echo 1 > /sys/class/backlight/acpi_video0/brightness
which works as expected. Brand new Zenbook UX301LA, Linux tpc 3.11.0-15-generic #25-Ubuntu SMP Thu Jan 30 17:22:01 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux.


If you have low end pc then switch the desktop environment as genome and unity both (default desktop) are bit heavy. you can install lightweight desktop environment like

xfce
mate
openbox
lxde
i3

If you have good pc or this is the first time you face the issue with same hardware then you might try to check the extensions you have installed and the window manager. And also make sure that your pc is not over heating(surprisingly this bring a lot of issue ) and if you are using external monitor then check for quality of the wire and the port. Also don't forget to keep drivers updated. If you have done any tweak to xorg(or other display related configuration that you are not sure about) reverse it. Also check for your current screen refresh rate(this plays vital role), if you think that is too low than your pc is capable of handeling then set it to higher value by
xrandr --output DVI-D-0 --mode 1920x1080 --rate 60.00

or any other value you want ( 1920x1080 is screen resolution and 60.0 is screen refresh rate )


Please help me with 32bit libs for 64 bit

Background

I managed to solve this issue and run Counter Strike: Source by installing Ubuntu's i386 versions of libs mentioned on ArchLinux forum by buhman.

Solution

Run following command in Terminal(Ctrl + Alt + T):

sudo apt-get install fontconfig:i386 libgtk2.0-0:i386 libxi6:i386 libnss3:i386 libpango1.0-0:i386 libpng3:i386 libasound2:i386 libcairo2:i386 libsdl2-2.0-0:i386 libsdl2-gfx-1.0-0:i386 libgcrypt11:i386

Hope it helps.


Under Ubuntu 18.04 my Java 10 application doesn't scale with the screen

Well, java does not use the system scale. You have to reconfigure your jvm with a scale configuration :
-Dsun.java2d.uiScale=2.0


you have to add a closing ; (semicolon) to each mysql command. In this case:

CREATE DATABASE logs;
USE logs;
CREATE TABLE FROM_DHCP(host varchar(35));

please note that even though the table will be created, you probably want to add a Primary Key to your table.

PS: only exception to the semicolon rule is the USE statement where you can omit it.


My Ubuntu won't install g++ but will install g++ 4.6 and g++ 4.7

If I have to guess, I will say that somehow your g++ symbolic link got damaged. A reinstallation of the g++ package should fix the issue:

sudo apt-get --reinstall install g++

Or, if you like doing things manually (you should try the above method first), you could:

If you have 4.6

sudo ln -i -s /usr/bin/g++-4.6 /usr/bin/g++

If you have 4.7

sudo ln -i -s /usr/bin/g++-4.7 /usr/bin/g++

If you have 4.8

sudo ln -i -s /usr/bin/g++-4.8 /usr/bin/g++


How do I redirect Google Chrome Logs out of my kern.log

If using an open source version of Chrome (like on Ubuntu the version installed with sudo apt-get install chromium-browser) then redirecting the seccomp logging requires a slightly-different rsyslogd filter.

For reference Chromium syslog messages look like this:

Feb 23 17:33:16 XXX kernel: [507549.071917] type=1701 audit(1393194796.933:3999): auid=4294967295 uid=1000 gid=1000 ses=4294967295 pid=21016 comm="chromium-browse" reason="seccomp" sig=0 syscall=2 compat=0 ip=0x7f2b40940eb0 code=0x50001

And building on stsquad's answer, here is an /etc/rsyslog.d/30-seccomp.conf that's been generalized to work with both Google Chrome and open source Chromium:

if $msg contains ' reason="seccomp"' and $msg contains ' comm="chrom' \
  then -/var/log/chrome-seccomp.log
& ~


What is the best notebook to run Ubuntu?

Take a look at laptops that come with Ubuntu pre-installed, they are meant to be running Ubuntu out-of-the-box without any issue:

System 76
Dell with Ubuntu

There are others that offer Ubuntu pre installed, such as Think Penguim and ZaReason.

Although you'd better take a look at Certified Hardware by Ubuntu, the Desktop section (Yes, it also includes laptops) is a full list of laptops that are meant to run perfectly with Ubuntu.


Laptop Brightness Problem on Toshiba Portege R705-P35

In 13.04, I found that /sys/class/backlight/toshiba breaks after suspend, but /sys/class/backlight/intel_backlight continues to function (echo $number > backlight after resume from suspend). Some great folks over at Arch have figured this one out. This does the trick:

Source: https://wiki.archlinux.org/index.php/Intel_Graphics#Backlight_not_fully_adjusting.2C_or_adjusting_at_all_after_resume.

Adapting this for Ubuntu 13.04:

sudo vi /etc/default/grub
change the line GRUB_CMDLINE_LINUX_DEFAULT as follows:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

sudo update-grub
Configure X11 to use the intel_backlight. Create a file called 20-intel.conf here:

sudo vi /usr/share/X11/xorg.conf.d/20-intel.conf

Paste in the following:

Section "Device"
        Identifier "card0"
        Driver "intel"
        Option "Backlight" "intel_backlight"
        BusID "PCI:0:2:0"

EndSection

6) Reboot and bask in glorious brightness control. Suspend/resume and it continues to function normally from the Fn-F6/F7 keys.


how to get DISPLAY variable at the ubuntu login screen?

When the system is first booting up, the display is sometimes not available until other background scripts have finished running. My solution is to add a sleep command before your display related commands to give the system time to finish loading. Something like:

sleep 5 && export DISPLAY=:0.0 && xhost +local &

The '&&'s chain the commands so that they run one after another, and the command following the && will only run if the previous command was successful.  The '&' at the end allows the command to run in the background so that the system can finish loading its necessary components. Without the '&' at the end, the system will not continue loading until the entire line has finished executing, which defeats the purpose of including the sleep command.


Zynaddsubfx fails to initialize with error message "Default I/O did not initialize."

I got this problem fixed by working with jack. Once I got jackctl set up, the problem disappeared. One of the biggest helps I found with qjackctl is this one here Ubuntu wiki How to JACK Configuration.

I think this had to do with the Frames/Period. Basically this is the buffer for qjackctl as explained on the wiki. Working with the settings on this and a few other settings helped tremendously.


Try to sudo apt-get install wine. Yum (an acronym for Yellowdog Updater, Modified) is a package management utility for RPM compatible Linux operating Systems.


Browsers not displaying websites correctly

Type about:config in the address bar. and search for layout.css.devPixelsPerPx double click and change the default value -1 try different value. in my case 1.4 works perfectly. Hope this help.


Netplan in Ubuntu Server 18.04. How to restart network fully?

netplan apply does the job.

In some cases you have to reboot.


How set CLASSPATH variable for a folder in Ubuntu

First, in general, setting the env var CLASSPATH usually causes more problems than it solves -- since not all app's want/need the same classpath, & often break when undesired or even unneeded jars are included in the classpath.  A java app should only include the minimum number of jars it requires, no more, no less.

When you have specific, individual apps that do require that the classpath be set, then usually the command-line option is preferred: java -cp path1:path2:....  Desktop icons can have their command altered to include these options, or shell scripts can be modified to include these options.

That being said (and since there are always exceptions to the rule), then depending on the version of java (this requres java 6 or later), you can specify that a whole directory of jars be added to the classpath by adding a "*" at the end of a directory; e.g, the following:

 /dir1/foo.jar:/dir2/dir3:/dir5/dir6/*:etc...

Means:

/dir1/foo.jar - (the single jar) will be added to the classpath;
/dir2/dir3 - all un-jar'd classes in this directory will be added to the classpath (must be in proper package structure; e.g, com.my.Foo.class must be in /dir2/dir3/com/my/Foo.class)
/dir5/dir6/* - all jars in this directory (i.e., /dir5/dir6/*.jar) will be added to the classpath. Note that this "*" isn't a wildcard (you can't use f*.jar or even *.jar); it's a special character indicating "add all jars"

In general, if you have to add a whole directory of jars to the application's classpath, the app was not bundled correctly.  Rather, the app should have a manifest containing the list of jars it depends on.  Or at the very least, only one jar should be added to your classpath, and that jar can have in its manifest the whole list of jars in some subdirectory.


How to install up-to-date virus scanner ClamAv in 12.04?

There is an option three:

3. The packagers at Canonical make a well-considered trade-off between stability and security, and you should worry less.

As the next three lines of your freshclam output most likely show (please add them to the question), your virus definitions are up to date. That's because Canonical -- or rather Debian, who do the original packaging of the package -- take security seriously.

What your freshclam output does show is that the installed software version (0.97.8) is behind the current production release (0.98.1). That's because Debian and Canonical are also serious about stability, in particular for an LTS release. You are on 12.04 for a reason, right?

To judge how well the packagers have made the stability-security trade-off, examine the ClamAV change log. I count 18 changes, 11 of which are not security-related or for different target platforms, leaving us with the following 7 potential security improvements (against an unknown number of newly introduced bugs):

 * Improvements to OLE2 extraction and scanning
 * xz file type support
 * bb #1570: Support ADC compression in DMG
 * libclamav: Add support for scanning xar/pkg archive files.
 * bb #8385: PDF ASCII85Decode zero-length fix
 * libclamav: SCAN_ALL mode fixes
 * bb #7436: elf64 header early exit

Trade-offs like security-stability are difficult to make, in particular for someone who isn't well informed. That's why I generally put more trust in the packagers than in my own judgment. And in case I need more certainty, I make sure that I base it on evidence rather than gut feeling.


How can I make the sidebar-width the default?

The sidebar-width is stored in the dconf database, which is best edited with gsettings (gsettings is the cli frontend to dconf).

You can do that either by GUI or command line:

1. GUI

Install dconf-editor:

sudo apt-install dconf-editor

Then navigate to "org" > "gnome" > "nautilus" > "window-state", and click on "sidebar-width". subsequently, either set a new value or click on Set to Default at the right/bottom of the window.

2. From command line

Either:

run the command:

gsettings set org.gnome.nautilus.window-state sidebar-width 200

to set a specific value, or:

gsettings reset org.gnome.nautilus.window-state sidebar-width

to reset to default (188 px)


Unable to connect to wireless network on Dell Inspiron 1525

Have you tried to see if you need to install proprietary drivers for your wireless card in the additional drivers menu?

Open the dash, type 'additional' and see if your wireless card is listed there. If it is, make sure the driver is activated and relog/reboot.


Why is "usermod -a -G" not adding my user to the group?

You need to log off and on the davea user to see that davea is a member of www-data group.


cant acess my old files because ecryptfs

In my opinion you have been a victim of Ransomware. It encrypts your files, and to get access to files, you must pay them. Here is the wikipedia page directed to Ransomware. Try exploring some methods. And enable your firewall on every OS/Not 100% safe, but can help for beginner type hackers/.


How to show windows only from the current workspace in Unity switcher?

For 12.04
This is the default behavior now!
For 11.10:
This isn't currently possible, however there is a workaround that you can set that will display the applications in your current workspace first, which means you can Alt-Tab to it quickly without having to go through applications in your other workspaces. Though this doesn't limit the switcher to the current desktop but it at least puts the apps on that desktop first:
First:

Install the CompizConfig Settings Manager
(CCSM).
Then go to the Switcher tab and select "Bias alt-tab sorting ...." and make sure you check the box.

How can I configure Unity?


How do I make the nVidia graphics card the default?

There is no way to set the Nvidia card as default except in the BIOS. Nvidia is finally working on drivers supporting Optimus and making bumblebee obsolete. Maybe it will be possible with that driver.

There is no way to say when the driver will be available, but it will need XServer 1.13 and Linux Kernel 3.5 which are included since Ubuntu 12.10.


These 3 should all do what you require and are in the repositories:
https://apps.ubuntu.com/cat/applications/precise/alarm-clock-applet/

Alarm Clock is a fully-featured alarm clock which resides in the notification area. It is easy to use yet powerful with support for multiple and repeatable alarms, as well as snoozing and a flexible notification system.
Two types of alarms are supported: Alarm Clocks and Timers. Notification is done by either playing a sound or launching an application.

https://apps.ubuntu.com/cat/applications/wakeup/

This package has a complete graphical front end with which a user can set an alarm to wake the computer - from poweroff if possible - and read a user-defined text. This text can grab relevant information (date, time, weather, Evolution schedule and tasks, news from an rss feed, number of new email messages, etc.) and speak that as well, or play music, all as defined by the user. More capabilities can be added to the alarm via a complete and simple plugin system. Supports multiple alarms.

https://apps.ubuntu.com/cat/applications/alarm-clock/

Alarm Clock is the personal alarm clock for GTK+ desktop environments. It supports sound fading, scheduled alarms, snooze option, passive window reminders, exception lists for scheduled alarms, exporting alarms and much more!


How can I change the window control button icons?

First go to System Settings > Theme > Window. This will redirect you to changing the icon of your window, popup & other system toolbars that are displayed on top of each program.


Can not see C drive ( windows installed ) in list of devices in Nautilus

Its very much likely that you might have extended your partition over a partition that didn't have enough space, so you might have overwritten some data.
However, thats not the only case. Probably nautilus is failing to pick up the C: drive.

So, for starters, try accessing disks as a superuser, that is, Ctrl+Alt+T to open the terminal, and type in:

  sudo gnome-disks

After Disks opens, try mounting the C drive manually.

If it doesn't work, try monting it again under sudo:

  sudo mount /dev/sdaX

..replacing X with the corresponding drive number for C.


How to disable password prompt while mounting partitions?

I would disregard any workaround and add a permanent mount entry into /etc/fstab.

Try man fstab for reference.

There are no definitive steps to doing a very specific mount. Each case comes with its variables. Anyway, running Terminal:

Run df -h and examine the output to know the block device address of your Windows partitions.
Edit /etc/fstab as super-user (e. g. using GEdit) and add entries for each Windows partition, like:

/dev/sdb2   /my_mount_point_folder  ntfs    rw  0   0

This will mount block device /dev/sdb2 at folder /my_mount_point_folder with read-write permissions. This happens with every boot, automatically.

That should do it. It is still good to review fstab manual: in Terminal run man fstab.


I finally found the problem - it was a corrupted wlan-router/dsl-modem combination. With new router and modem everythings works fine.


How to write two install .iso (for example windows and linux) on one flash?

You can use YUMI (Your Universal Multiboot Installer). Its a great utility to list down multiple ISO files in one boot menu.


Detailed Instruction on how to make virtual packages

Ubuntu only knows about its package system. It isn't going to integrate with CTAN's. If you want to trick APT into thinking that you have Ubuntu versions of these packages, you have to do that yourself. And it probably won't work perfectly.

You can use the equivs package to easily make a package that Provides all of these packages. That should work.


"This connection was reset, The connection to the server was reset while the page was loading." is a problem that has occurred with Firefox for many years. It has nothing to do with ubuntu or Windows or any other OS. It can be caused by several different things.
Most people have found that by uninstalling firefox and then installing the latest version has solved it. And some people have needed to update their operating system to get it to work. The other thing has been Firefox being blocked by the firewall.
The information you posted shows your are receiving and transmitting (RX & TX) so we can tell you are actually connected to the internet.
You can install Opera or Midori browser just to see if they are connecting to the internet, which I think they will.
Another thing that sometimes solves this is to reset your modem!
One other thing is to turn off IPV6 in Firefox.
here are the instructions right from Mozilla's site:
IPv6

By default, Firefox/Mozilla Suite/SeaMonkey will use IPv6 ("Internet Protocol version 6") if it is available. However, the user's local network or Internet environment may not be equipped to handle IPv6 and you may see an "Address not found" or "Server not found" error for many websites. (Read bug 414197 and this forum discussion for examples.)

To disable IPv6, change the preference network.dns.disableIPv6 from "false" to true . Here are the steps:
 Type about:config in the address bar, press Enter.
 Find network.dns.disableIPv6 in the list.
 Right-click -> Toggle to True
 Restart your Mozilla application and try again.

If this doesn't work, you can re-enable IPv6 by resetting the preference to "false" (double-click to toggle).

Here are two links to Mozilla that deal with your trouble:
http://kb.mozillazine.org/Error_loading_some_websites
http://kb.mozillazine.org/SSL_is_disabled


Ubuntu the difference between sudo apt-get upgrade and sudo apt-get install?

Short answer citing the comment by @Evgeniy Yanuk

For install you have to point a package or packages you want to install or upgrade. upgrade checks all your installed packages and updates them if it's needed.

Update

Update the list of all current program packages in the repositories in order to determine which packages are candidates for upgrading.

sudo apt-get update   # old syntax
sudo apt update       # new syntax

Upgrade

Upgrade all current program packages in the Ubuntu operating system, that are installed automatically or from the repositories or from a PPA.

sudo apt-get upgrade  # old syntax
sudo apt upgrade      # new syntax

or if you want to upgrade and also perform checks and fixes to upgrade to a fully upgraded and compatible system (this is what I do),

sudo apt-get dist-upgrade  # old syntax
sudo apt full-upgrade      # new syntax

Install a program package, a new package that was not yet installed

sudo apt-get upgrade  # old syntax
sudo apt upgrade      # new syntax

Update & Upgrade

When you intend to upgrade the system (within the same version of Ubuntu), you can run one of the following command lines

sudo apt update && sudo apt upgrade
sudo apt update && sudo apt full-upgrade

Install

When you intend to install a new program package, you can run the following command lines. It is a good idea to update before installing.

sudo apt-get update                        # old syntax
sudo apt-get install program-package-name  # old syntax

sudo apt update                            # new syntax
sudo apt install program-package-name      # new syntax

Edit:

If you call apt install without any parameter (no package specified), it will tell you if there are packages to upgrade, but it will not upgrade anything.

end of edit

Manual page

You find more details in the built-in manual

man apt-get  # old syntax
man apt      # new syntax

Upgrade to a new version alias release of Ubuntu

This is a completely different task. It is complicated and risky. Backup everything that you don't want to lose before you start on this venture.

sudo do-release-upgrade

You find more details in the built-in manual

man do-release-upgrade

This method works from a previous version to the next version. There is one exception: You can also do-release-upgrade from the previous LTS version to the next LTS version, for example

from Ubuntu 14.04 LTS to 16.04 LTS
from Ubuntu 16.04 LTS to 18.04 LTS

Before starting you should

remove all PPAs and non-standard program packages (that do not belong to the Ubuntu repositories), because they can break the release-upgrade process,
update & full-upgrade the current system, so that it is up to date.

Install a fresh system

It is often easier and faster to install a fresh system than to do-release-upgrade, particularly if there are several steps, or if the new version is very different from the previous one.

Remember to backup everything that you don't want to lose before you start on this venture.


What you are doing here is ambiguous even in bash.
In bash, if the noglob option is not set and mate-* matches one or more files in the current directory, it will be expanded to a list of those files which will be passed as arguments to apt-get remove. Otherwise, it will be passed literally to the apt-get command unless:

the failglob option is set, in which case the behavior will be the same as in fish
the nullglob option is set, in which case mate-* will be removed altogether

In fish, the behavior appears to be equivalent to bash's failglob, and there does not seem to be an equivalent of bash's set -o noglob or set -f. So you will need to prevent globbing explicitly by quoting, ex.
sudo apt-get remove "mate-*"

or
sudo apt-get remove mate-"*"

(which you really should be doing in bash, for the reasons outlined above).
See also:

Fish for bash users: Wildcards (globs)

Also be aware that apt has moved away from simple wildcards altogether in favor of aptitude-style patterns - see Problem using wildcard with apt.


It took some time to stabilize the fan's behavior. Now no more weird sound, I think the original reason was an opensource driver of my discrete video adapter.

So probable solutions:
1) turn off the discrete video adapter;
2) install the latest proprietary driver.


In Ubuntu Desktop 14.04 the acl option in /etc/fstab and mount command is superfluous, even when the option defaults is not specified.

Instead, the noacl option disables acl support


"--scale 2x2" in xrandr causes the monitor to not display anything

Just wanted to add that this is something I've been fighting with for a long time, and each time I just gave up - until I decided to figure it out once and for all. The solution below works for me, hope it does for you as well.

tl;dr: Configure ForceFullCompositionPipeline=On

Background

Some of this is also in hopes of providing more keywords in case someone with a similar problem ends up looking for the solution.

My setup is:

ThinkPad P50 with a built-in 4K display at 3840×2160 (primary)
An external monitor as a secondary display - Dell U2412M - 1920×1200

I use Ubuntu Gnome 16.04 LTS.

When I plug in the monitor via a HDMI cable + a HDMI-to-DVI converter (as the monitor doesn't have an HDMI input), everything was too large. Various articles online suggested using xrandr to configure --scale 2x2 on that display, which resulted in it being almost completely black, with only a thin line visible on top.

I bumped into this question and while the 2x2.001 scaling solution enabled the monitor to actually display stuff, it also added an extra pixel below the X screen which resulted in slight up/down scrolling when the cursors reaches the top/bottom of the screen.

After a lot of Googling, much of which yielded problems and no solutions, I stumbled upon this: https://devtalk.nvidia.com/default/topic/891207/-355-11-358-09-viewportin-on-2nd-monitor-results-in-garbled-display-for-values-over-3211x1800

So to test it out, I configured this using the following commands - assume xrandr hasn't been configured with scaling yet.

$ nvidia-settings -q CurrentMetaMode

  Attribute 'CurrentMetaMode' (lilicorp:1.0): id=50, switchable=no, source=RandR :: DPY-4: nvidia-auto-select @3840x2160 +0+0 {ViewPortIn=3840x2160, ViewPortOut=3840x2160+0+0}, DPY-1: nvidia-auto-select @1920x1200 +3840+0 {ViewPortIn=1920x1200, ViewPortOut=1920x1200+0+0}

This displays the CurrentMetaMode value and this is where I added the ForceFullCompositionPipeline=On option to both displays. Note that DPY-4 is my built-in laptop display, whereas DPY-1 is the external monitor.

The actual string that needs to be configured is the one after :: in the output of that command.

$ nvidia-settings --assign CurrentMetaMode="DPY-4: nvidia-auto-select @3840x2160 +0+0 {ViewPortIn=3840x2160, ViewPortOut=3840x2160+0+0, ForceFullCompositionPipeline=On}, DPY-1: nvidia-auto-select @1920x1200 +3840+0 {ViewPortIn=1920x1200, ViewPortOut=1920x1200+0+0, ForceFullCompositionPipeline=On}"

After this, I ran:

$ xrandr --output DP-1 --scale=2x2

Finally, the external display resolution was fine with no scrolling or any other issues.

Note that after running those commands, the CurrentMetaMode is a bit different from what was assigned, probably due to the scaling getting applied:

$ nvidia-settings -q CurrentMetaMode

  Attribute 'CurrentMetaMode' (lilicorp:1.0): id=50, switchable=no, source=RandR :: DPY-4: nvidia-auto-select @3840x2160 +0+0 {ViewPortIn=3840x2160, ViewPortOut=3840x2160+0+0, ForceCompositionPipeline=On, ForceFullCompositionPipeline=On}, DPY-1: nvidia-auto-select @3840x2400 +3840+0 {Transform=(2.000000,0.000000,0.000000,0.000000,2.000000,0.000000,0.000000,0.000000,1.000000), ViewPortIn=3840x2400, ViewPortOut=1920x1200+0+0, ResamplingMethod=Bilinear, ForceCompositionPipeline=On, ForceFullCompositionPipeline=On}

Hope this solves the problem for someone else too!


I finally figured the proxy variables are either stored in ~/.bashrc, /etc/bash.bashrc or /etc/environment. I had edited the /etc/environment file before and I forgot that. I grepped each file for proxy and I the lines were in etc/environment.

I removed those lines and now its working fine.


What about Ubuntu 12.04 core updates every 6 months?

If you are using the update-manager client you can just unselect the update that you don't want to install. I haven't updated my kernel for some time because of a problem with the laptop screen brightness that I don't want to fix every time.

the other option is to put those packages on hold. I havent done this in a long time and not in Ubuntu, but there is a guide for Debian. check chapter 7.12.


GUI Crashed when updating 10.04 to 12.04 using the update-manager

Before you go any further I seriously recommend backing up all your data, and all the hidden dot files in your home directory.  To make a list of installed programs do:

dpgk --get-selections | grep -v deinstall > ubuntu-files

This will make a file in the current directory called ubuntu-files which will contain a list of everything that is installed.  To restore this list to the system do the following:

### Make sure the system is fully updated if it isn't already:
sudo apt-get update && sudo apt-get upgrade
### Install the dselect tool (probably depracated)
sudo apt-get install dselect
### Give the package list to dpkg so it knows what to install
sudo dpkg --set-selections < ubuntu-files
### Use dselect to initiate installation (option 'I' will do it)
sudo dselect

Please note that this will install everything in the list you made in the first step.  If you're doing this after upgrading the release level then the results may not be ideal - for example open office will may installed when the default for 12.04 should actually be Libre Office and so on.

To try to kick the distribution upgrade off again do the following:

### Make sure the package lists are up to date.
sudo apt-get update
### install update-manager-core if it is not already:
sudo apt-get install update-manager-core
### Kick the release upgrade off again...
sudo do-release-upgrade


Which file stores the default reboot message broadcast?

The default shutdown message is hard coded in /lib/systemd/systemd-logind. If you want to broadcast a different message then you must adopt a different strategy; for example, you may want to look periodically for /var/run/reboot-required. See How does Ubuntu keep track of the “System restart required” flag in motd on ServerFault.


Is there an Ubuntu version of the software for the Microsoft Ergonomic Natural 4000 kb?

I'm using this keyboard with XFCE on Ubuntu 18.04. The zoom slider works out of the box.

If you find that all function keys are not working on the Microsoft Natural Ergonomic Keyboard 4000 v1.0
check that the F-lock is toggled.  On the top row of the keyboard, next to the F12 key there's a button called F lock. Pressing it toggles a green LED at the bottom of the keyboard with an F below it.  When the LED is off, the function keys F1, F2 etc don't work.


If you already have it in your PPA, then you (or something acting on your behalf) must have already run dput or its equivalent.  Perhaps you're using a source package recipe on Launchpad that does it for you?


Your screenshot shows the machine is unable to resolve "ubuntu-server.local", it doesn't even get as far as actually pinging it.

Which DNS server is responsible for the .local domain on your LAN? You need to add the IP for it into the list of resolvers in Network Manager so the machine can find it, since it's not something that would be returned by any DNS server on the general Internet.


How do I upgrade juju from a development version to a release?

The link to this bug may help you:
https://bugs.launchpad.net/juju-core/+bug/1325040

I think you need:

  juju upgrade-juju --upload-tools


Pirateplayer Not able to install, old repository for Qt desktop components!

The dependency that will be missing from that repository is qt-components-desktop. Here's the source for Qt Desktop Components. It contains compile instructions in the Readme, and should be easy enough to compile in 12.10. dpkg will still complain about qt-components-desktop missing but it should still work if disabling dependency checks. A cleaner way to do it, than removing dependency checks, would be using Checkinstall to make a qt-components-desktop package.


How to access serial ubuntu host serial port on VirtualBox guest OS

Setting up a serial port for VirtualBox is not easy, mainly because of many options on how to transfer data from the host to the guest. For transferring data from/to an attached device (here a modem) the following settings should work:

Of course you will have to adopt setting for your device on the host (that would be /dev/ttyS2 in your case).

If using an IRQ greater than 15 for the host you will have to enable I/O APCI as shown here:

After a setup depicted in the example here your Windows guest will see a virtual type 16450 serial port on COM1 using IRQ4 and I/O Port 0x3F8. Data will be transferred from and to host device /dev/ttyS20.


Count number of files in a folder per day

You can do this using the printf action of find to print only the modification times in desired format, and then using sort and uniq:

find . -type f -printf '%TY-%Tm-%Td\n' | sort | uniq -c

-printf '%TY-%Tm-%Td\n' prints the modification time of files in e.g. 2015-05-23 format
sort sorts the output and uniq -c does the count by date

Example:

~/foobar% find . -type f -printf '%TY-%Tm-%Td\n' | sort | uniq -c
      3 2004-06-29
      1 2004-08-23
      1 2004-09-15
      1 2004-09-18
      1 2005-07-24
      1 2006-02-05
      2 2008-06-25
      3 2008-12-31
      1 2009-03-13
      1 2009-04-30
      1 2010-04-04
      2 2010-09-01
      8 2011-07-13
     15 2011-08-27
      3 2011-11-03
      3 2014-10-08


There is a bug filed in Launchpad very similar to the above problem.

One message contains a quote from the source detailing when this error condition occurs:

  The error message "Unknown sequence number while processing queue"
  occurs in a chunk of text that has this big fat warning in front of
  it, about threading safety in client code:

/* Thread-safety rules:
 *
 * At most one thread can be reading from XCB's event queue at a time.
 * If you are not the current event-reading thread and you need to find
 * out if an event is available, you must wait.
 *
 * The same rule applies for reading replies.
 *
 * A single thread cannot be both the the event-reading and the
 * reply-reading thread at the same time.
 *
 * We always look at both the current event and the first pending reply
 * to decide which to process next.
 *
 * We always process all responses in sequence-number order, which may
 * mean waiting for another thread (either the event_waiter or the
 * reply_waiter) to handle an earlier response before we can process or
 * return a later one. If so, we wait on the corresponding condition
 * variable for that thread to process the response and wake us up.
 */

  This seems to suggest perhaps this client application could have some
  faulty logic in its thread handling as relating to the xcb calls?


How do I add downloaded debian packages to Synaptic Package Manager?

According to this question you are misusing this feature. Apparently, this feature in Synaptic is not for installing individual DEB package files.

To do this - without using the command line - navigate to the folder where the packages are and double-click one (or more?) of them. This will bring up the Package Installer and you should be good to go.


This error comes if another program is making some operations on packages (e.g. you're running an update, you have Synaptic opened, etc. ). Only one program at a time is allowed to do so.

The way the package manager ensures this, is to check if a file /var/lib/dpkg/lock exists when it starts operating. If it doesn't exist, then the program creates one. It then removes it when it finishes its operation. So if the file exists, it means that another package operation is running, or that an operation didn't finish correctly and thus didn't delete the file.

Check that the program you're using (no matter if this is Synaptic, Ubuntu Software Center or command line apt-get) is the only one open at the moment.

Try also to wait some time: Ubuntu checks periodically for updates, and if you're trying to install VLC while this is happening you might get the error. It should take maximum a few minutes (less than one with a good connection), so if after a short time you still get this error, this is not the problem.

If you have checked all the previous and you're still having the issue, there's two possibilities:

there is still a dpkg process running in the background: you can easily check by opening System Monitor, looking at processes running and search for dpkg. Or, in a terminal, run ps aux | grep dpkg | grep -v grep: if you get nothing, you're sure this is not the case. If, instead, you find a dpkg process, then something is running. Try waiting. In any case, after restarting your machine the problem should not appear any longer.
At some point, a package operation (installation, update, removal, or any other) crashed/failed/was incorrectly interrupted. This means that it was unable to delete the file /var/lib/dpkg/lock, as explained. In this case, you can safely remove such file. From a terminal, run sudo rm /var/lib/dpkg/lock.

After this, you should be able to install any software again


Unetbootin commands for installing ubuntu 13.10

Well, since you're running Ubuntu, you don't need to use Unetbootin. As minerz029 said, you can just use Startup Disk Creator. It should already be installed.
To find it, press the Super key (looks like the Windows icon) and type in "Startup Disk Creator" at the top.
Then, afterwards, everything should be pretty straightforward. Choose your usb, find your iso, specify how much space, then just let it install. It'll take a little bit.


How to disable GUI and only use terminal?

By stopping the GDM service sudo service GDM stop you are being dropped to the Linux Virtual Console. There are 7 of them, accessible by the keyboard shortcuts Ctrl-Alt-F1 through Ctrl-Alt-F7.

My guess is the blinking cursor you see is present on the first console. When you type Ctrl-Alt-F2 you will switch to the second console, where you'll be presented with a login prompt. Simply enter your username and password to login!

Beware though that most people would find using their computer directly from the virtual console a huge pain. Still, I believe that disabling the GUI is a great way to start your journey of truly learning how Linux-based systems actually work.

Personally, I installed the xinit package and got rid of GDM entirely. Whenever I need to do graphical work, I run startx to start the X windows server.


How to restore a system after accidentally removing all kernels?

Boot into a live CD (or live USB), mount some systems, chroot into it and install the kernel. After a successful installation of the kernel, unmount the filesystems.

Open Terminal
Mount the Ubuntu partition: sudo mount /dev/sdXY /mnt
Mount some special partitions:

sudo mount --bind /dev /mnt/dev
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys

(optional) When you are connected to a network, use the DNS servers from your Live environment (otherwise host names can possibly not be resolved):

cp /etc/resolv.conf /mnt/etc/resolv.conf

Chroot into the /mnt: sudo chroot /mnt
Install the Linux kernel: apt-get install linux-image-generic (no sudo required as you are root after a chroot)
After a successful installation of the kernel, get out the chroot and unmount some filesystems:

exit
sudo umount /mnt/sys
sudo umount /mnt/proc
sudo umount /mnt/dev
sudo umount /mnt

Reboot and remove CD or USB: sudo reboot


Ok so I searched many posts and founded a post in which he said to try this command in terminal
sudo sed -i 's/3/2/' /etc/NetworkManager/conf.d/*  and restarted network manager by using command sudo service network-manager restart after disabling ipv6 and this worked .


How to update manual page in Ubuntu 12.04?

Right, the ip subcommand tuntap is described in man ip under 14.04 Trusty, but not under 12.04 Precise.

If the command itself in the latest repository version for Precise does indeed support ip tuntap, the missing description is a bug that should be reported for the package iproute2.

The man page is in the main package, iproute2. The package iproute2-doc does exist, but is an empty transitional package, with dependency on iproute2.

I do not know how to best get a package installed with an updated man page - it may not be easy, because the software is in the same package.

But you can get the man page versions of the Ubuntu releases online at http://manpages.ubuntu.com - for example man ip for Precise and man ip for Trusty.


Start a new usable konsole terminal with a command

You could try a script so you would call

konsole -e <script>.sh

And then in the script place

#!/bin/bash
<command>
exec bash

And that should keep you konsole open after words then just shortcut it


/casper/vmlinuz.efi: not found for ubuntu 14.04.2 LTS

create new Virtual Drive.
Loop that drive: losetup -f new_hard_disk_4_Vmware.vmdk
dd if=ubuntu.iso of=/dev/loop(x)
losetup -d... or better still, gnome-disks -> detach with the button.
Mount new VMDK as drive 2

That or loop the ISO into fuse, and ride it as mounted by the os.
as a CD-Rom


How to Fix Ubuntu 17.10 / Java 9 HDPI Scaling?

Run using GDK_SCALE=2 java ... (doesn't work for Oracle Java 8 ...)


install ruby 2.3.1 - Ubuntu 19.10 - Build Failed

It seems you need an older version of open ssl. Check this link https://github.com/rbenv/ruby-build/wiki#openssl-usrincludeopensslasn1_mach102-error-error-this-file-is-obsolete-please-update-your-software


The problem is with a previous apt command? None of the to install packages has a reference to springseed.

check /var/lib/dpkg/info/ for a post install file named springseed and
remove it.

Your install will then no longer complain about it.

Did you try to install springseed itself perhaps? If so their package is broken ... edit: and has been since 2014 it seems. Filename to remove is /var/lib/dpkg/info/springseed.postinst according to the link.


Is there some index of Ubuntu architecture/version number combinations?

Yes, there is.

http://releases.ubuntu.com/ and  http://cdimage.ubuntu.com/ubuntu/releases for most current
http://old-releases.ubuntu.com/releases/ for old and unsupported ones.


Changes to the KDE library prevent compiz 0.9.7.12 from compiling

You are lacking of the correct headers to compile it. Do:

sudo apt-get install kde-workspace-dev

and the error will go away. Maybe you want to do:

sudo apt-get build-dep compiz

so you get all the build dependencies.


Sony Bluetoothc headset WH-1000XM3 Ubuntu 16.04

I installed blueman and it helped me with the recognition of my headset. I first deleted the previous profiles of attempted connections with the headphone saved in my PC (this was a required step).
Later I started a clean connection, it got recognized, then I selected Audio Sink profile instead of headset or handsfree. After this you must see the bars on the right side changing colors which means there is data being transferred.
Finally,in Blueman, right click on your device and change the "Audio profile" to A2DP sink.
Regards,
America


How can I integrate Dropbox with PCManFM?

Install libfile-mimeinfo-perl from the repository
Run (in terminal) mimeopen -d ~/Desktop (any folder can be used)
mimeopen should prompt you to pick something to open it with. For me, PCManFM was the first option. Select the option that lists PCManFM.
Open Dropbox from the system tray. It should now open in PCManFM.


12.04 Unity middle mouse activation of compiz window scaling

Assuming I read your question correctly, I was able to set middle mouse button to enable Window scale. From what I see, it is no longer part of the default settings but you can easily set it this way using CCSM .

Once you have installed it, open CCSM and search for Scale.

Then go to Bindings tab in Scale and click on Initiate Window Picker (the third option with a mouse icon next to it).

Click on the checkbox next to Enable and choose Button2 in the dropdown list.

Now that all the settings are set, log out and back in and you would now be able to enable Window scaling using your middle mouse button.


From your Question and comments the resolution will be the following:

Boot to the live disk and run these steps.  the /dev/sdXY is replaced for the specifics of the information you have provided.

The c6 in step 1 and the a in step 4 are variables.  The c6 should be replaced with the partition of your Ubuntu install.  The a should be replaced with the default boot that you have set in your bios.

The prefix :$ and :# are the command prompts you see on the terminal.

1:$ sudo mount /dev/sdc6 /mnt
2:$ for i in /sys /proc /run /dev; do sudo mount --bind "$i" "/mnt/$i"; done
3:$ sudo chroot /mnt
4:# grub-install /dev/sda
5:# update-grub
6:# exit
7:$ for i in /sys /proc /run /dev; do sudo umount "/mnt/$i"; done
8:$ exit

Reboot.

Ensure that you have UEFI enabled in your BIOS if is a later model computer with that feature.


You need to download AMD drivers for Linux from their site and install it.

  AMD Drivers http://support.amd.com/en-us/download

And yes there are games for Linux, you can download Steam and play a lot of games like CS:GO, War Thunder, Tomb Raider and many others.

  Steam download for Ubuntu http://store.steampowered.com/about/

But if you want to play for example League of Legends because there is no LOL for Linux you can simply install wine and install windows application under Linux. If you want more info just search in google for WINE

  How to install Wine: https://wiki.winehq.org/Ubuntu


There's an essential difference between grep and look:

Unless explicitly stated otherwise, grep will find patterns even somewhere within the lines. For look the manpage states:

  look — display lines beginning with a given string

I'm not using look very often, but it did work fine on a trivial example I just tried.


RAID 1 detected as RAID 0 when one drive is missing

A colleague has suggested a good solution. It's basically to create a systemd service that will run at startup and ensure that madadm starts the RAID array. The command to start the array is:

/sbin/mdadm --manage --run /dev/md127

On a good raid array this will do nothing since it's already started. On a bad array this will start the raid before it is mounted.


How to grant write permissions in Samba?

Samba has its own layer of access control for each share. There are two basic options

read only: by default every share is read-only, regardless of filesystem permissions,
writeable: in order to allow write access you should set writeable = Yes.

This should be enough to solve the problem. But if you'd like to learn more about Samba permissions, like how to set umask, enable guest account or control access for individual users/groups, then read the short tutorial on Samba permissions.


Dual GPU (Nvidia + ASPEED) extended desktop configuration help Ubuntu 16.04

Here is why:

Aspeed is your onboard GPU, whose driver is not provided by Nvidia. Thus, it not showing up in your Nvidia X server settings should be expected.


sha1sum

  Print or check SHA1 (160-bit) checksums.  With no FILE, or when FILE is -, read standard input.

sha1sum {file}

If you want to send the file together with its sha1sum output redirect the output to a file:

sha1sum {file} > {file}.sha1

Send both files and the other party can do a...

sha1sum -c {file}.sha1

It should show OK if the sha1 is correct.


I should think Audacity would be able to do this.

EDIT:
OK, Well, I'm not up with all of the Audio jargon, so here's a few things I found: Spek (and its GUI, pulseview) and Sonic Visualiser and I also found this page, which contains many links to different software for Linux.


Dual Boot ubuntu with Windows 10 - using one of two internal hard drives

If the HDD is really empty, you can just use dd to copy the Ubuntu ISO to the drive, wasting most of the 2T space, and boot it to install to the SDD.  Afterwards you can simply repartition the HDD and do something else with the drive when ready.  Most of the tools for burning ISOs go to some lengths to prevent writing onto a hard disk, for fear you are making an error.


Bad system performance (ASRock X299 Taichi + Intel i7 7820-X)

Update: the kernel patch for incorrect TSC frequency issue has been merged. Building a kernel with this patch fixes the issue.

https://patchwork.kernel.org/patch/10177619/
https://github.com/torvalds/linux/commit/b511203093489eb1829cb4de86e8214752205ac6#diff-96989d5a06fa45e5014d1613838a4f86


How do I change the size of the compiz window shadow?

The setting is not controlled by Compiz; they are part of the ambiance theme. Here is what I did to tame the shadows. Open a terminal and complete the following:

cd /usr/share/themes/Ambiance/metacity-1
sudo nano metacity-theme-1.xml

Find the line (use cntl+w) that says:

<shadow radius=”45.0″ opacity=”0.75″ color=”#abde4f” x_offset=”1″ y_offset=”4″/>

Change the radius to a value you can deal with… I chose 10.

You may also want to move this theme to your local .themes folder.


Configure your player for channels, If you are using Totem, got0 edit-preferences-Audio and change the Audio Output type to 5.1,


IBus is used for typing non-Latin characters for languages like Chinese, Japanese, or Korean. If you don't need to type characters in these languages, you should be ok without running IBus.


Why does it take so much time to initialize mlocate database?

I installed ubuntu lts 20 on wsl2 on Windows 10 via Microsoft Store. It didn't came with locate installed, so I installed it. While installing, it got stuck for a long time at 60% when updating its database for the first time. Thought it went into some problem and Google it (and found this thread).
Turns out it eventually finished installing after like 15 min. When I used the command for the first time, I got a surprise: it actually parsed all my hard drive into its database, including all Windows stuff, even things I can't access normally through Windows.
So I think the reason the mlocate installation took so long while stuck at 60% was because with was also indexing Windows files.
Well, if you waited a whole night, then it may be a real problem with the installation. I would suggest to install another distro on your wsl or, at least, don't install locate on it.


The quotes around the initial "EOF" prevent variable expansion. To use variables in the heredoc text, you need to an unquoted delimiter:

cat > filename <<- EOF
Hello $1
More contents, etc...
EOF

But then you'll have to be careful about shell syntax in the rest of the contents.

Another option is to write this line separately, and write the fixed contents using a heredoc:

echo "Hello $1" > filename
cat >> filename <<- "EOF"
More contents, etc...
EOF

Note the use of >> for appending after the initial write.


Wireless unstable with an Atheros AR9285

Try changing the "WPA group rekey interval" on your WiFi router, this is working for me now. It was set to 2 before I changed it to 3600, the value is in seconds. This is working now, I tried disabling hardware encryption and power management, but that did not work.

I am now trying other combinations with enabling power management and hardware encryption, as these are desirable features on a netbook :)


How do I see my added adapter on the /etc/network/interfaces file?

The only entries that automagically appear in /etc/network/interfaces are those detected during installation. Otherwise, you'll have to add those yourself, manually, with whatever configuration you need.


To ensure that you really talking about root check the uid of the account.
After login invoke id. The output should be:

uid=0(root) gid=0(root) groups=0(root)

root is just a name, the special rights belong to the uid 0.

If you have a 2nd account root with a "normal" uid different from 0 delete this bogus account.

If your root account has the uid 0 ensure that the sshd configuration deny root login.
Ensure that /etc/ssh/sshd_config include the setting:

PermitRootLogin no

Note: Ubuntu has surely a root account. The difference to other distribution is, that normally no password is assigned to this account.


Using rsync with sudo on the destination machine

On the destination machine

Find out the path to rsync: which rsync
Edit the /etc/sudoers file: sudo visudo (see also: must I use visudo?)
Add the line <username> ALL=NOPASSWD:<path to rsync>, where username is the login name of the user that rsync will use to log on. That user must be able to use sudo

Then, on the source machine, specify that sudo rsync shall be used:

rsync ... --rsync-path="sudo rsync" ...

Using it without the NOPASSWD on the destination machine will result in the message

  sudo: no tty present and no askpass program specified


Why is dd creating an enormous file when I try to create a backup disk image?

If you copy  a  partition with  dd, the output file will be as big as the partition.  dd does a physical copy of the disc, it has no knowledge of blank or used space.

If you compress the result file you will save a lot of space, though, given that blank space will compress away very well (beware, this is going to be computationally very heavy). You can even compress the output of dd on the fly, with something on the line of dd if=/dev/sdaX | gzip -c > compressed_file.gz.

really important:

  Moreover, you cannot (never) do a dd on a live  (mounted)
  partition, the data recorded will be totally inconsistent and
  absolutely not useful for a backup. Think about it: blocks of data are
  continually allocated, moved and deleted; is like shooting a photo
  with long exposure time to a moving target.

  To copy the partition with dd you must boot from a different one -
  live USB or whatever.

What would I do to solve the problem at hand (notice, only generic instruction because you need to know what you are doing)

First option buy Norton Ghost, or explore the opensource options: partimage and clonezilla (never tested myself).

Second option do it manually:

create an extra partition for backups, call it /dev/sdX (or use a common data partition, whatever).
to backup:

boot with live usb
mount the real root partition in /real
mount the extra partition in /extra
do a big tar, on the line of (cd /real && tar cvf /extra/mybck.tar.gz)

to restore

boot with live usb
mount the real root partition in /real
mount the extra partition in /extra
restore, on the line of (cd /real && tar xvpf /extra/mybck.tar.gz), beware of the p option to preserve metadata
chroot in /real
update grub or the bootloader you are using

You can substitute tar with your preferred archiver, just be sure it will respect ownership/mode of files. rsync is worth exploring.


Epson Perfection V370 scanner stopped working after upgrade to Ubuntu 17.10

I just upgraded to Ubuntu 17.10 and experienced the very same problem like the op; however, I was able to fix it for me in four steps:

sudo ln -sfr /usr/lib/sane/libsane-epkowa* /usr/lib/x86_64-linux-gnu/sane
sudo vi /etc/udev/rules.d/79-udev-epson.rules

contents:

ATTRS{manufacturer}=="EPSON", DRIVERS=="usb", SUBSYSTEMS=="usb", ATTRS{idVendor}=="04b8", ATTRS{idProduct}=="*", MODE="0777"

sudo ln -sfr /usr/lib64/sane/libsane* /usr/lib/x86_64-linux-gnu/sane/
reboot

See also https://bugs.launchpad.net/ubuntu/+source/sane-backends/+bug/1728012


I have the exact same.

Few monts ago i got it working by installing 3.6 kernel to 12.10, yet it needed this trick to work:

when the desktop is loaded touch the screen and see the cursor in one of the corners of the screen, no matter where you touch the cursor is always in that corner, if this happens, restart X and it should work properly.

if you cant see the cursor when touching then restarting X wont help. sometimes lsusb did not list the device


The problem starts here: linuxtv.org/patch/13647

Where the correct firmware is stored on the web is not something I have yet discovered. In Mint 14 an even earlier firmware version is default.

Where it goes is: lib/firmware

Kirby


I just hit the same problem. The solution is to check if you have pip

sudo apt-cache policy python-pip

which should return either:

python-pip:
  Installed: (none)
  Candidate: 1.5.4-1ubuntu3
  Version table:
     1.5.4-1ubuntu3 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty-updates/universe amd64 Packages
     1.5.4-1 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages

meaning it isn't installed. Or:

python-pip:
  Installed: 1.5.4-1ubuntu3
  Candidate: 1.5.4-1ubuntu3
  Version table:
 *** 1.5.4-1ubuntu3 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty-updates/universe amd64 Packages
        100 /var/lib/dpkg/status
     1.5.4-1 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages

if it is installed. If not installed run:

sudo apt-get install python-pip

Now you can run pip to get the new sympy

pip install --user sympy

Finally back to octave to run

pkg install -forge symbolic

or

pkg install /PATH/YOU/DOWNLOADED/TO/symbolic-2.2.4.tar.gz

if you downloaded the tar of the version you need.

Last and final step: Each time your run octave, you need to load the symbolic package,

pkg load symbolic

or you can put this command in your ~/.octaverc.


How to watch movies compressed into .bin and .cue?

Accordinq to this blog, you can use VLC to watch your .bin videos.

From a more general point of view, VLC is famous for supporting nearly all the existing formats in video and audio.


Apache and mod_mono - only serves HTML files

It is definitely not the optimal solution, but commenting the first and last lines seems to solve the problem. I do get a warning on double-loading, but now I know that with those lines the file isn't even read.


how to connect to MiniDLNA / ReadyMedia running on a public internet server?

In the meantime, I came to the conclusion my setup is not working because port 1900 is used for IP multicasting with the Simple Service Discovery Protocol (SSDP). Clients (e. g. VLC) send out discovery requests to multicast address 239.255.255.250, which is not routed on the public Internet. VPNs based on OpenVPN currently do not handle multicasts out of the box, unfortunately. Yet, there is a possible solution to this in the form of an additional daemon.


Different Terminal Colors under same user

gnome-terminal allows you to create multiple profiles. In Edit->Preferences create as many as you wish, possibly each with different color scheme, different font etc. Right clicking allows you to switch profile at any time.