Ubuntu 14.04 + Windows 8.1 Grub not showing (Boot-repair didn't work)

I've found this in the end of my log file

  For example you can boot into Windows, then type the following command
  in an admin command prompt: bcdedit /set {bootmgr} path
  \EFI\ubuntu\shimx64.efi

So I've tried it and it worked.
But I'm still curious what have happened and how I can prevent it from happening again...


Best way to manual decompress kernel Ubuntu

It is better to use extract-vmlinux for several reasons:

You don't know what kind of compression is used. It could be gzip, LZ4, Bzip2, XZ, … The latest extract-vmlinux script knows how to extract every kind of compressed kernel, though you will still need the relevant command line utility.
Compressed kernels aren't like simple compressed files. They are self-extracting so contain a binary header. The kernel image itself may have other binary objects before or after it also. I'm surprised that zcat worked for you; simply using lz4cat doesn't work for me with LZ4-compressed kernels.

For a different reason than yours I wrote a kernel install hook script that uses extract-vmlinux to decompress LZ4-compressed Ubuntu kernels. This should help you along in your quest to have the same for Raspberry Pi.


You can try grub-customizer. You have to add the PPA to ubuntu and then install it. (See this question for information on PPA safety.)

From terminal:

sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt-get update
sudo apt-get install grub-customizer

Then launch it and you should be able to set windows as main selection and to hide what you want. It's not to hard to use.


What works for me
Install Eclipse from repository
sudo apt-get install libjpeg62
Install the plug-in instead of the portable
It all just works.


What tools can resize the partition where Windows7 resides?

As far as partition resizing goes, GParted is already a good tool for that. I've got Windows 7 and Ubuntu 14.04 on my laptop, and used GParted to resize both partitions. If you look at the GParted screen-shot, the key icon tells you those partitions are locked. You're aware of that right ? Boot of an Ubuntu live usb, unmount the hard-drive, and open GParted. Unlock the partitions, and resize them as desired. Also, good idea is to free-up space by deleting stuff you don't need, or move it to optical disks/USB sticks/cloud storage.

More info :http://www.howtogeek.com/114503/how-to-resize-your-ubuntu-partitions/


How can I remove a clickable bar with hyperlink in each page of a pdf file?

Removing Links

You can remove embedded links (inserted by authoring applications or by Acrobat). Here’s how to do so in Acrobat X or XI:

Choose Tools > Document Processing > Remove All Links


I had the same error as the original poster, which led me here.

The 40-libsane.rules file and the sane compatibility list suggested it should "just work", so I tinkered a bit and found that if you change the setting in Simple Scan preferences called Scan Side and set it to Back (rather than the default Front and Back), all is good.


Razer Megalodon USB with Ubuntu 13.04 = disaster

Seems to me the problem is related to pulse audio. I suggest you reading this where further info is provided, instructions of how to solve it are also there.

This might be related to this bug.


Driver needed for wireless adapter WNA3100

First, I recommend the amended version.

Here is a link to a copy on my personal Dropbox: https://dl.dropboxusercontent.com/u/58267392/Broadcom_bcm43xx_USB_32_64bit_v2_amended.zip


There is a long an details description on the code blocks wiki: Install Code Blocks from source on Linux

The process is not trivial and requires several steps before building the project with:

Read the wiki entry and follow the steps carefully
Download or checkout the source code
Bootstrap, configure, and make code blocks

$  ./bootstrap
$ ./configure
$ make

Use checkinstall, to generate and install a Debian package.

$ sudo checkinstall


Xububtu trusty - cannot switch to other input methods when logged in with subsequently accounts created

As far as I know those ibus settings are user specific, so you probably need to select the desired engines via ibus-setup for each user.


How can I detect motion in a long, mostly dull video?

VLC

VLC has a motion detection filter that you can try by accessing: Tools -> Effects and Filters -> Video Effects -> Advanced -> Motion Detect.

You might have more tweaks available running it from the command line with the --video-filter=motiondetect flag; check out this example.


How to run Ubuntu 12.10 on a Laptop with maximum power saving?

try installing jupiter

sudo add-apt-repository ppa:webupd8team/jupiter
sudo apt-get update
sudo apt-get install jupiter

this may work


It appears that there is a space in the name:

  ~/Downloads/Drivers/Broadcom BCM4352/Broadcom

Linux and, especially 'make' is troubled by spaces. Please rename the file to something like:

  ~/Downloads/Drivers/Broadcom_BCM4352/Broadcom

Then try again:

cd ~/Downloads/Drivers/Broadcom_BCM4352/Broadcom
make
sudo make install

I assume that you are compiling this driver because you are having trouble with your wireless. I suspect this driver will not solve it. After it is installed and you reboot, please start a new question to tell us the specific problem you are having.


Installing realtek RTL8812 driver for ac 1200 inamax dongle

In order to compile a kernel module, in this case a wireless driver, in Ubuntu requires the source code for the driver, which you have, as well as several build tools. If you could get a temporary internet connection by ethernet from a friend or by tethering your phone, installing the prerequisites is quite simple. From the terminal:

sudo apt update
sudo apt install build-essential

Without the possibility of a temporary connection, it will be necessary to go here: http://packages.ubuntu.com Find and downlad on some other computer all of the necessary packages and their dependencies. Transfer them on a USB key or similar. The process and a handy list are here: https://ubuntuforums.org/showthread.php?t=2439074&p=13940917#post13940917 Although the package bcmwl-kernel-source is included on the list, it is not required in this case.

Once all of the packages are installed without error, you are ready to compile the driver. From the terminal:

cd ~/Downloads/RTL88x2BU_WiFi_linux_v5.1.7_19806
chmod +x install.sh
sudo ./install.sh

Assuming that install process completed without error, load the module:

sudo modprobe 882xbu

Your wireless should now be working.

NOTE: I have some suspicion that this relatively old (2016) driver may not compile correctly in Ubuntu 18.04.4 LTS. If it does not, I will have an alternative solution.


Where most of log files located: /var/log/

Log filename: Xorg.0.log Xorg.1.log etc...

Update:

You can check out the log files:

Click on

System menu > Choose Administration > System Log

or

Applications > System Tool > Log File Viewer


Unable to install boot repair using Ubuntu live usb

If you are unable to install it from a live cd,I would recommend you to download an iso image file of boot-repair software and you can burn it to a cd or a usb using yumi or unetbootin

Here's the download link where you will get the iso image:

  http://sourceforge.net/projects/boot-repair-cd/files/latest/download

For unetbootin for making a bootable usb:

  http://sourceforge.net/projects/unetbootin/files/latest/download?source=directory


From Terminal-1, Create new terminal, execute command (e.g: start JBoss), come back to Terminal-1

You can simply do :

gnome-terminal -e jboss_command; exit;

That should close the new terminal as soon as the jboss_command finishes.

However, you almost certainly don't want that. There is no reason to open a new terminal. Just run your command in the background:

jboss_command &

If that creates output, run it like this:

jboss_command &>/dev/null &

The & at the end makes a command run in the background, allowing you to keep using the terminal. &>/dev/null redirects standard error and standard output to /dev/null, it basically discards any messages printed by the command. So, running your jboss command like this will enable you to keep working on the same terminal while the command is running.


How do I disable automatic printer discovery in Ubuntu 20.10+?

The only application that discovers printers on the network and sets up permanent print queues for them is cups-browsed. Purging it from the system is the surefire way of preventing this. Why bother stopping and masking it? It's a waste of time when all you want to do is prevent discovery and set up of a printer. But stopping and masking has gained traction without its proponents explaining why it is better than purging cups-browsed.
That's one issue. Now for a second, completely separate one.
The GTK print dialog (used by Gnome) also discovers and displays printers. It does not install print queues. The displayed printers (which are not queues) often do not print. This is a bug in GTK. A user can do nothing about it.
Are you experiencing the first or second issue? That will decide your course of action.


Playing old shockwave flash games on Lubuntu 17.04

Alternative 1: Without a browser
As Adobe only provides a 64-bit standalone player this alternative is merely for 64-bit users (uname -m → x86_64).</>

Download the Adobe Flash standalone player:
wget https://fpdownload.macromedia.com/pub/flashplayer/updaters/32/flash_player_sa_linux.x86_64.tar.gz

Extract the files:
tar -xf flash_player_sa_linux.x86_64.tar.gz

Run the standalone player with
./flashplayer

or call it directly with a .swf file:
./flashplayer /path/to/file.swf

You can move the flashplayer file to wherever you want, I recommend to save it in a folder like ~/scripts/ and define an alias like alias flashplayer='~/scripts/flashplayer' in your ~/.bash_aliases file. This way it's stored where it belongs and you can still run it from every directory just by typing flashplayer.
Alternative 2: Using a browser

Install the Adobe Flash plugin from the Canonical Partner sources1:
sudo apt install adobe-flashplugin

Run the file in your browser by entering file:///path/to/file.swf in the address bar.

1 You may need to activate those source first with sudo add-apt-repository "deb http://archive.canonical.com/ubuntu $(lsb_release -sc) partner" && sudo apt update.


Take a closer look at the error message, and you will see that a space is missing between 3306 and -j

iptables-restore v1.6.0: invalid port/service `3306-j' specified

Try using this code snippet which includes a space.

*nat
:PREROUTING ACCEPT [0:0]
-A PREROUTING -p tcp --dport 3306 -j REDIRECT --to-port 33060 COMMIT


Can't install software because "No module named 'debconf'" error in apt/dpkg

You are getting this error because your Python 3 installation is broken. It can not import the debconf module. You can confirm this by trying the following:

$ python3 -m debconf
/usr/bin/python3: No module named debconf

If this is the case, you should check that the debconf.py file exists in /usr/lib/python3/dist-packages and that this directory is on your sys.path.

In the past, I've experienced this problem when I installed a custom Python interpreter. Make sure that the command type python3 returns /usr/bin/python3.


SMB encryption for connection from internet

One way is to disable encryption, as well as direct access from the Internet, and use a VPN instead.  Another is to set up a second instance of samba ( on an alternate port ) just for serving access from the Internet and configure that one to require encryption, but not the local instance.


Finally found the answer myself.

I used the Ubuntu VM to shrink my pi images. The host machine - OSX.
The image file was in shared folder (host-VM)

In order to be able to mount the .img as loop device make sure to set the permissions of the .img file to 766 or 666.


Cadence can't start ALSA -> PulseAudio -> Jack (Plugin) bridge

You have alsa routed to pulseaudio and then to jack. It's always on so you don't need to start it.
If you don't want to use pulseaudio, click the dropdown box labeled "bridge type" and select ALSA -> JACK if available.


Because the file name has spaces in it, you need to use quotes or escapes so the space does not make it look like 3 different file names:

chmod a+x "Hello World BASH"
"./Hello World BASH"

Or

chmod a+x Hello\ World\ BASH
./Hello\ World\ BASH


The helpticket folks at jungledisk/rackspace resolved this problem. It appears that jungledisk was expecing libnotify.so.1 and ubuntu had libnotify.so.4.

Creating a symlink pointing to libnotify.so.4 resolves the problem...

  The new Ubuntu is missing libnotify.so.1 needed by jungle disk. This
  is resolved by creating a symlink to libnotify.so.4 to libnotify.so.1.
  Please [enter the commands] below and restart the machine:

  cd /usr/lib/i386-linux-gnu/ ; sudo ln -s ./libnotify.so.4 libnotify.so.1

  Regards, JungleJason


I believe I have the same issue with Ubuntu 14.04 (xfce).

I originally thought it was because I had added SQLite Manager to Firefox (it stopped responding) however it doesn't seem to be related to that.

I find that the problem appears and if left alone will resolve itself within a few minutes.

During the period of odd-response, the mouse right-click menu may not work, possibly due to a an incorrect focus. I have found that I can click the taskbar and bring an application to the front but I cannot access the application (eg cannot write in a document, cannot left-click to move the cursor).

With the keyboard, shortcuts I have added (SUPER+L, SUPER+E) don't work but some key combinations do work (CRTL+ALT+F1). I can switch to a terminal and work in the terminal. Originally I would go to a terminal and kill X but when I realised that it would come good after a period, I now just wait.

Computer is Dell Latitude E6500.


Mouse requiring clicking twice in most cases, not sure why?

This issue turned out to be that Ubuntu's drivers for the Magic Mouse (hid_magicmouse I think?) introduce a middle button region on the Magic Mouse. When disabled this acts as a dead zone. I discovered that my finger was sitting right on the edge of the left click region and the right click region so my first click was often in the middle while my second click was just slightly more to the left and hence it worked.

Although I didn't try this, I theorize you could reassign the middle region to behave as left click as well.

Thank you for your feedback guys.


Solution: I've resorted to reinstalling Ubuntu, it takes less time to do that than fix my disk.

Thank you for your time.


You can use mutool, a MuPDF command-line tool (sudo apt-get install mupdf-tools):

mutool poster -x 2 input.pdf output.pdf

You can also use -y if you want to perform a vertical split.


You'll need to be looking at Lubuntu or Xubuntu, possibly others, as they both offer 32 bit versions where Ubuntu does not...


How do I install drivers for TP-Link 802.11ac Wi-Fi USB adapter?

You can install the driver this way. Connect to Internet some other way and run in terminal

sudo apt-get install git dkms
git clone https://github.com/abperiasamy/rtl8812AU_8821AU_linux.git
sed -i 's/\#MODULE_VERSION\#/0.1/' rtl8812AU_8821AU_linux/dkms.conf
sudo dkms add ./rtl8812AU_8821AU_linux
sudo dkms install -m 8812au -v 0.1

Then insert your dongle.


Website crashed after installing ZPanel on Ubuntu 12.04

You can remove zpanel and reset http.conf and vhost.confg file:

httpd.conf

Set your directory of your website to load:

DocumentRoot "/var/www/html/mywebsite.com/public_html"

on last line of httpd.conf remove the line:
Include /etc/zpanel/configs/apache/httpd.conf

vhost.conf

<VirtualHost *:80>
     ServerAdmin support@my-website.com
     ServerName my-website.com
     ServerAlias www.my-website.com
  DocumentRoot /var/www/html/my-website.com/public_html
  ErrorLog  /var/www/html/my-website.com/log/error.log
  CustomLog /var/www/html/my-website.com/log/access.log combined
</VirtualHost>

Replace my-website.com with your web domain


How do you install less css command line compiler?

I'm not entirely sure if by compiler you want something that will automatically compile your less files on the fly or on the server.  Because otherwise you can

$ sudo apt-get install node-less yui-compressor

(On Ubuntu 12.04, the node-less package is called node-less.)

and then,

$ lessc example.less > compiled_example.css
$ yui-compressor -o small_and_compiled_example.css compiled_example.css


Sony VAIO keyboard only responding after suspending the device/restarting the X-Server

I had the same problem and it was solved with installation of new drivers for touchpad.
Download this archive (from Ubuntu's bug reporting page).
Open a terminal, and follow these steps (after step 4, you will have no mouse at all):

cd ~/Downloads
sudo dkms ldtarball psmouse-elantech-x551c.tar.gz
sudo dkms install -m psmouse -v elantech-x551c
sudo rmmod psmouse
sudo modprobe psmouse

Solution details can be found here - http://www.evilcodingmonkey.com/2014/01/23/ubuntu-activate-multi-touch-on-elantech/


Dropbox problem in Indicator applet in Gnome classic

I had the same problem and this solved the issue for me :

dropbox stop && DBUS_SESSION_BUS_ADDRESS="" dropbox start

I found the answer at : Dropbox icon is not working Xubuntu 14.04 LTS 64

EDIT : This solution seems working only for the active session. And this one works after a reboot too : https://askubuntu.com/a/737615/545036


Connected to wireless network but no internet

I know it sounds dumb, and I am by no means an expert, but have you tried resetting your computer or router? Also, have you tried the new LTS release 12.04? You can try it via a live usb and see if it fixes your issue. If so, you may want to consider upgrading. Furthermore, did you install any programs or updates before you last shutdown the computer?

I know the above sounds like your standard IT suggestions, and are perhaps obvious, but if you haven't tried them you may be pleasantly surprised. In my experience as an "average user" (with limited command line knowledge), often a simple restart fixes the problem. Also, try reconnecting to the network and pining sites to "force" an internet reconnection.


Ubuntu server starting in read only due to issues with sda1

Posting my fix for anyone who has this issue in the future.

Download Live CD iso
Open GParted
Right click -> Unmount (may not need this step, my partition wouldn't mount to   begin with)
Right click -> Check
Edit Run -> Run Queue
Reboot to main OS


yes amigo we have one.

First uninstall , installed vim with

sudo apt-get autoremove vim

and then add the below PPA

sudo apt-add-repository ppa:dgadomski/vim-daily

then install it with

sudo apt-get update
sudo apt-get install vim

that will adds a daily build PPA of vim.

The last build was done 6 Hrs ago.


Can you help diagnose why this laptop running Ubuntu has crashed and seemingly died

The screenshot says "unrecovered read error", which usually suggests that the hard drive is dying. Get a new hard drive.

However, if this is the second hard drive dying in your laptop in a short period of time it may suggest that the problem is somewhere else - maybe in the SATA controller, faulty RAM, laptop overheating etc.

At any rate, Ubuntu is not at fault :)


One possible solution to this would be check the permissions on the actual file. Navigate to that folder in terminal type 'll'.

A list of all the files and folders in the directory will print out in a format like this:

drwxr-xr-x eric eric 4096 May 18 21:02 Android/

The string "drwxr-xr-x" represents the permissions on the file. If the 'r' in the third character from the right is missing ( is a '-' ) then other users do not have permission to read this file. You add this permission for a file by typing:

chmod o+r filename.txt

For a more detailed explanation of permissions, check:
https://help.ubuntu.com/community/FilePermissions


How to run VM's within Ubuntu Linux without Virtualbox or any other type 2 hypervisors?

KVM will be a good option - of course you still have to install proper pieces of software, KVM binaries, some extra tools etc. It integrates with Linux kernel (as modules), which make it pretty much type 1 virtualization.


video-dummy - The Fake display with/without monitor connected at the same time

Main problem here is that the KMS (Kernel Mode Setting) is on in modern kernels. This needs to be disabled by creating rules to modprobe depending your card:
For ATI graphics:
echo options radeon modeset=0 > /etc/modprobe.d/radeon-kms.conf

For Intel graphics:
echo options i915 modeset=0 > /etc/modprobe.d/i915-kms.conf

For Nvidia i suggest blacklisting nouveau driver and use vesa on xorg.conf
Now if your modeline is setted correctly you should be able to connect your monitor on the fly.


According to ubuntu's wiki you have to run this command

sudo update-grub2

Edit : Here is the page of the wiki i mentioned.


Explaining the contents of the ~/.profile file

Simplified version:

if [ -n "$BASH_VERSION" ]; then
    # include .bashrc if it exists
    if [ -f "$HOME/.bashrc" ]; then
    . "$HOME/.bashrc"
    fi
fi

This parts checks wheter ~/.profile itself is being sourced by a Bash instance, and if that's the case sources in turn ~/.bashrc; this is  a way to include the user's settings stored in ~/.bashrc e.g. also in login shells, which normally don't source ~/.bashrc;

if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
fi

This part checks whether ~/bin exists, and if that's the case prepends ~/bin to the current value of $PATH; this is done so that potential executables / scripts present in ~/bin take precedence over executables / scripts present in other paths included in $PATH (e.g. by placing an executable named cat in ~/bin, when running cat that executable would be run in place of the usual /bin/cat).

Detailed version:

if [ -n "$BASH_VERSION" ]; then
    # include .bashrc if it exists
    if [ -f "$HOME/.bashrc" ]; then
    . "$HOME/.bashrc"
    fi
fi

This part checks whether the expansion of $BASH_VERSION has a non-zero lenght (if [ -n "$BASH_VERSION" ]), and if that's the case, if the expansion of $HOME/.bashrc exists and is a regular file (if [ -f "$HOME/.bashrc" ]), the expansion of $HOME/.bashrc is sourced.

Since Bash sets $BASH_VERSION upon invocation, checking whether $BASH_VERSION has a non-zero lenght is a robust way of determining whether the file itself is being sourced by a Bash instance.

This is why when invoking Bash as a login shell on Ubuntu the user's settings stored in ~/.bashrc are included (this is not necessarily the case for other distributions); Bash itself only sources ~/.profile when invoked as a login shell, and this is a way to go around that;

if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
fi

This part checks whether the expansion of $HOME/bin exists and is a directory (if [ -d "$HOME/bin" ]), and if that's the case prepends the expansion of $HOME/bin to the current value of $PATH (PATH="$HOME/bin:$PATH"; $HOME is normally set to the user's home directory).

This is done so that potential executables / scripts present in the expansion of $HOME/bin take precedence over executables / scripts present in other paths included in $PATH.


It appears you don't have internet access during this attempt. Try to ping google.com or go to the internet and if you can then try to run again. I have had issues with internet access after waking up my laptop from sleep, so I would at least try "systemctl restart networking".

It may also be worth checking to see if the /boot/ partition is full. Run "df -h" and see how much space is available there.

I know my answer might sound a bit silly, but you cannot forget to check the basics before trying to update/upgrade/install packages.


How to install Debian with encrypted / and passphrase required before login-screen?

First of all, this is off topic and should probably go to unix.stackexchange.com instead.

That said, the setup for encrypted root is the same as with any other encrypted partition. One thing you have to keep in mind though: You need to make a separate /boot partition, which must not be encrypted.

As always with questions regarding the installation of Debian, I refer to the really excellent documentation of Debian. The chapters relevant to you are:

http://www.debian.org/releases/stable/amd64/ch06s03.html.en#di-partition

http://www.debian.org/releases/stable/amd64/ch07s02.html.en


Mozilla plugin not found to install icedtea

Installing firefox-dev should be sufficient for this.  xulrunner isn't supported as a standalone component in Ubuntu anymore.


OS Not found in the GRUB after Complete installation

If I were in that situation, I would redo the installation from scratch.

If you want to experiment a bit, load the rescue CD, drop into a root shell and try to re-grub the system again.

Another thing that I might do is load the rescue CD, drop into a root shell, mount the boot or root partition of the system disk (depending on how the installation was done) and see what is in the boot area, to see if a valid kernel is present, and then check the grub to see if the textual boot options menu is ok.  You might try to fix the grub memu if that is all you find is wrong.


Preseeding or fixing "Force UEFI installation" on Hyper-V installation?

This solution worked for me when I was working on a gen2 template
https://github.com/taliesins/packer-baseboxes/blob/master/hyperv-ubuntu-16.04.json


GNOME Shell interface not working anymore after NVIDIA X Server settings changes

try to look at the problem easier )

Perhaps, just together with updating Xorg was changed default shell setting. If you install full GNOME3 pack then you should to have option in your Greeter(or standart Gnome Login) the menu for choosing shell.

GNOME3 include 3 'features':

Gnome
Gnome Classic
Gnome Classic (without effects)

Or if this solution is not figure out of problem then post some screens.

Also I suppose so that maybe problem of using LightDM instead GDM.
To fix use solution from:
GDM killed on startup

Also very recommended to reading and bookmarking:
How do I install and use the latest version of GNOME?


installing Ubuntu in Virtual machine for Windows 7 host

I guess your ram is not too big, how much RAM do you use on the Virtual Machine? While the minimum RAM for running Ubuntu is 2 GB, if it is shared with a virtual machine it might take too long when booting on a virtual machine.


How to view HTML files thumbnail preview in nautilus

From What rendering engine does Nautilus use to show HTML previews/thumbnails?, Refresh thumbnails in nautilus and How I repaired my html thumbnails questions, I finally figured it out.

Install gnome-web-photo if you don't have it.
sudo apt-get install gnome-web-photo
Clear thumbnail cache
rm -r  ~/.thumbnails
killall nautilus

Enjoy html thumbnails in nautilus.


Colibri opens instead of PDF and image files

Repair PDF opening in KDE

follow this guide:

https://www.ryananddebi.com/2014/09/29/linux-fixing-pdfs-opening-in-gimp-in-firefoxzotero/

basically edit (or create if not exists):

SUDO_EDITOR=kate sudoedit /usr/share/applications/mimeapps.list

and add this block:

[Default Applications]
application/pdf=okularApplication_pdf.desktop


If you are getting'DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER' it could be possible that your BIOS is unable to read the medium it is trying to boot from.

You should probably try troubleshooting this by verifying your bios' boot order, and also confirming that the machine can boot correctly from other sources...

Your issue should have nothing to do with the capabilities of your hardware, the current Ubuntu system requirements are:

700 MHz processor
512 MiB RAM
5 GB of HDD space

It is possible that iso you downloaded was corrupted, you should verify the hash by following the instructions found here, to at least verify that the iso you are using is not corrupt.If you cannot check the hash or there is an error You could simply download a new image create new cd/usb key.

Given the older hardware you may also want to consider checking out lubuntu instead, as you may have a better experience with it, it uses far less resources that ubuntu does.


Command-line to list DNS servers used by my system

resolv.conf isn't really used anymore, unless you implement it yourself.  The network manager does it now.  I created an alias to list the DNS servers on my system, as I sometimes switch from OpenDNS to Google's open DNS.

Ubuntu >= 15

nmcli device show <interfacename> | grep IP4.DNS

Ubuntu <= 14

nmcli dev list iface <interfacename> | grep IP4

In my case, <interfacename> is eth0, which is common, but not always the case.

See if this is what you want.

EDIT:

I think resolv.conf is actually used indirectly, because the network manager creates the server that listens on 127.0.0.1, but I was told that this is an implementation detail that should not be counted on.  I think that if you enter DNS addresses before this entry, they might get used, but I'm not sure exactly how this works.  I think it's best to use the network manager in most cases, when possible.


Unable to start Apache Tomcat 8.5.4 on Ubuntu 16.04

Make user 'tomcat' owner of the whole tomcat directory using below command:

cd /opt && sudo chown -R tomcat tomcat/

It worked for me.


wrong reference to home user shortcuts in 'unity launcher

Is the path correct when you scroll over the library on the right side from nautilus? fix those by dragging the correct library to the right hand pane and then remove the incorrect one from there.


Ubuntu server detecting electricity outage?

First of all this seems to be a very interesting project. As far as I know most modern UPS have a USB connection to provide a shutdown signal to the connected computer. You could analyze the signal your UPS might provide you. To control the three child server you could send a shutdown command via ssh (pub key authentication) upon power loss.

Maybe there is another plug-and-play device that could monitor your power plugs voltage and send it's data to the parent server if the first option is not working.

If there is no such device listed above and your UPS don't provide a signal cable, the only way I see is "hacking" the UPS itself and grab some electrical signal that could trigger a Raspberry Pi port which shuts down your machines via ssh.

But be carefull because you are dealing with high voltages and high currents that can do lethal harm if they are not treated with extreme caution.

To boot up the machines again you should look into your BIOS. Most modern Motherboards have the WakeOnLan function which powers the computer up if a correspinding signal is recieved via LAN.


alacritty receives strange keystrokes when switching workspace

I contacted the Alacritty developers and it seems to be a bug from Alacritty which should be solved now in the current “master” branch:

https://github.com/alacritty/alacritty/issues/3229

So I guess I'll just wait for the update to be shipped through the PPA.
I'll update this answer when the bug is fixed in PPA version.

Apparently this only appears under X11. I was surprised to learn that I am running X11, I though Ubuntu switched to Wayland by default.


Why is my background image always disappearing when I log in?

Maybe image's path didn't have the right permissions, try to move one to your Pictures directory and tell me if it still get lost on new sessions.

If that's the problem you could set the rigth permissions to your images's folder running:

  gksu nautilus

and through the properties dialog set permissions for your user to read-whrite that directory, remember to press apply to enclosed files button.


What is memcached? Is it good for gaming or virtual machines?

No, memcached is not good for gaming or virtual machines.

Memcached is a daemon (a program that stays in the background and responds to requests) allowing application developers to easily implement memory storage that is shared between separate processes, especially in web applications.

Traditionally, web applications run every individual web request in a separate environment that is initialised at the start of the request and destroyed at the end, and/or in multiple separate processes that share no memory with each other.  This allows no "objects" or other variables stored in memory to persist between separate requests.  This is true, for example, of PHP.

Memcached is a process that web applications can connect to and use for storing persistent variables, values and objects in memory.  The stored data can then persist between different web requests.

This is immensely useful when each web request needs data from a relatively slow storage mechanism such as a database server accessed over a network socket. Instead of each web request causing a new request to the database server, the application may choose to "cache" some of these requests in a memcached instance so that future requests can just access this.

Memcached also has advanced features allowing these shared memory objects to be distributed across multiple servers, and the like.

Memcached needs to be installed separately to the web server (eg Apache, nginx) and application server (eg PHP) for web applications that require it.


how to uninstall ubuntu 12.04 from virtualbox 4.3

In the VirtualBox Manager interface, right-click on the virtual machine you want to remove and just hit Remove... and select Delete all files from the dialog.


How can I recover files deleted by rm command on 14.10?

If you go to the Ubuntu software centre and search for UNDELETE then you will find a couple of utilities which may be able to help.

I also strongly suggest setting up a backup!


Ubuntu 12.10 DisplayLink Adapter No Green Screen

As it turns out, the adapter will not be recognized by the driver unless you plug in the adapter after initial startup.  For me, that means plugging it in at the logon screen.


Kerning is activated by using the Format->Character menu, selecting the Position tab and using the Pair kerning checkbox in the Spacing section.


Battery indicator has disappeared from Gnome panel

Note: Try steps 4/5 first, it may be fixed with 1st hit.

Below the extended instruction to debug the problem with the indicator.

Check if indicator-power-service is running:

ps ax | grep indicator-power

If it's running, try reset its settings then restart it:

dconf reset -f /com/canonical/indicator/power/
pkill -f indicator-power-service

No success, locate it then try it from terminal (looking for any errors in output):

sudo updatedb; locate -r indicator-power-service$

My system is 64bit, So:

/usr/lib/x86_64-linux-gnu/indicator-power/indicator-power-service

If it works with command, then some thing wrong with its autostart.
As it was checked, it isn't running on start up. Verify the existence of:

/usr/share/upstart/sessions/indicator-power.conf

description "Indicator Power Backend"

# Want to move to indicator-services-[start|end], but that's not all
# there yet.  Use the signals that exist today for now.

start on indicators-loaded or indicator-services-start
stop on desktop-end or indicator-services-end

respawn

exec /usr/lib/x86_64-linux-gnu/indicator-power/indicator-power-service

/etc/xdg/autostart/indicator-power.desktop

[Desktop Entry]
Type=Application
Name=Indicator Power
Exec=/usr/lib/x86_64-linux-gnu/indicator-power/indicator-power-service
NotShowIn=Unity;
NoDisplay=true
StartupNotify=false
Terminal=false

This works for me with a fresh Ubuntu 14.04, Modifing indicator-power.desktop for autostart conditions similar to the other indicators. (Submitted bug report lp#1330302)

sudo nano /etc/xdg/autostart/indicator-power.desktop

Remove:

NotShowIn=Unity;

Replace it with:

OnlyShowIn=Unity;XFCE;GNOME;
AutostartCondition=GNOME3 unless-session gnome

Logout/Login

Well if it didn't work:

Try purge it then reinstall it:

sudo apt-get remove --purge indicator-power
sudo apt-get install indicator-power

Reboot, Check again
No success, as workaround you can run it this way (you may close terminal after this):

/usr/lib/x86_64-linux-gnu/indicator-power/indicator-power-service & disown $!

& run it in background
disown $! command to detach a process for current terminal, $! variable that hold PID of last process run in background

Or better if add it to user startup applications, see How do I start applications automatically on login?


I found a bug report on launch pad describing the same problem and some solutions: Samsung 7 screen brightness

Basically ACPI is implemented improperly on your motherboard with Intel CPU and Radeon graphics. The solution is to add the parameters acpi_osi=linux and acpi_backlight=video to your kernel command lines in Grub. You can google how to modify grub kernel parameters and ask any questions you have on updating grub.


error: no such partition (duplicate, but none of the others helped, unless I missed one)

Get a windows 7 DVD or USB-drive. Boot from it and select Repair.Select Use Recovery tools
And from last click on command prompt And type these commands

 Bootrec/FixMBR

 Bootrec/RebuildBCD

This will restore your Windows boot-loader and replace grub..


updated to PHP 7 and got all my php.ini link to php_curl.dll instead of curl.so

/usr/lib/php5/sessionclean: 12: /usr/lib/php5/sessionclean: php5: not found

I just updated php on my Debian and had the same error. Check if you fully deleted php5, I had to manually uninstall package php5-common. (Package php5 was however uninstalled automatically by dist-upgrade)


WPS Office cannot access files on Virtualbox Shared Folder

So it looks like your user id needs to belong to group vboxsf to read/write the shared directory.

In a terminal, enter groups, and check if the list contains vboxsf. If not, enter:

sudo usermod --append --groups vboxsf  {your id}

This will ask for your password. You have to logoff/logon the id for the group to be effective. Use groups again to check that it worked.


Increase verbosity of running rsync process?


Technically it is possible to add bionic source list.
You can edit /etc/apt/sources.list file for it and replace focal with bionic for main repositories. I would not recommend this way as it will result in broken dependency tree.
To work around you can try downloading .deb package from Bionic repo. Here again it will not work without its dependencies and libraries may be conflict. Try it on your own risk. This is also not recommended way.   You need to wait until bug is fixed for Ubuntu 20.04 as of now.


Wireless not working.Toshiba P50-A-12z-. Artheoos. Ubuntu 12.04 (LTS)

SOLVED!

Thanks a lot! I followed the solution posted by chili555 in the following link

http://askubuntu.com/questions/331667/no-wireless-for-intel-corporation-7260-version-63

And now my wireless works great. Again, thanks a lot. You guys rock!

PS. Don't get frustrated with people that don't find answers already posted in the forum. I spent hours browsing different solutions but could not find the right one until I was directed to it.

Just in case it helps to other non-expert people (like me) reading this post. My system (12.04) showed only up to /lib/firmware/iwlwifi-6050-5.ucode and no signs of the required 7260 that was needed for my intel device (see above). Now the 7260 ucode file is there. One obvious thing I tried a couple days ago was ubuntu 13 but could not even see the live CD (computer just stopped working in the middle of reading the DVD and I tried this multiple times with identical results).

I might ask your help again with my screen in the future (I think it has some compatibilty issues but works well for most prurposes so no urgency here) if I don't find a solution in the older posts.


According to the search on https://packages.ubuntu.com you need to install the following packages - libappindicator-dev and libgtk2.0-dev:

sudo apt install libappindicator-dev libgtk2.0-dev

and then retry with sudo cpan -i Gtk2::AppIndicator.


Suspend and resume isn't working on an ASUS X54CBBK3

"[...]Remove the comment sign from the line SAVE_VIDEO_PCI_STATE=true in the file /etc/default/acpi-support. "

A comment found on this thread.
Hope it helps! :)


I have solved it after much work. I think what must have happened is that a garbled bluetooth code must have been transmitted somehow. Even turning the Bose off then on did not work. What was needed was with bluetooth all ON on the computer, and the Bose ON, hold down the bluetooth button on the Bose mini soundlink for 10 seconds, it bleeps and is rebooted and reconnects and hey presto the audio now works! Hope this may help someone else.


Do older repositories no longer work with newer Ubuntu version?

Is there no backwards compatibility between repositories?

Yes, there is but to some extent. For Ubuntu versions you can use repositories through the versions that are not end of life but mixing releases is not recommended.

1 problem you will run into is when there is a big change in the default software. Ubuntu went from Gnome to Unity so any tool depending on the old style will be buggy or completely useless. That probably includes that Mint Menu.

  If someone stops maintaining a repository, is it basically dead and useless?

Ubuntu will move the default repositories to an archive so these are still usable to Ubuntu users. How others deal with this is up to them. Personal archives tend to be available on launchpad for all releases (even those end of life).


The temperature in Celsius is hard-wired into Jupiter.

Fortunately, Jupiter is written in Python - this makes it very easy to change.

First backup your copy of jupiter:

cp /usr/bin/jupiter ~/jupiter

Next edit the file:

gksudo gedit /usr/bin/jupiter

Find the following section in the file:

def get_temperature(self):
        temp = int(self.collect_data(self.temp))
        temp = temp / 1000
        return str(temp) + ' ºC'

change to:

def get_temperature(self):
    temp = int(self.collect_data(self.temp))
    temp = temp / 1000
    temp = ((temp * 9) / 5) + 32
    return str(temp) + ' ºF'

Save, logout and login.

Obviously, an update to the jupiter PPA will overwrite your changes.

You can either disable the PPA, or save /usr/bin/jupiter as (for example) /usr/bin/jupiter2.  In your startup applications, change the jupiter startup command to python /usr/bin/jupiter2


CLI log screen for USB to serial in ubuntu 16.04 is not working

Reinstall solved the issue. Uninstall it first.

apt remove screen && apt purge screen

the reinstall again

apt install screen


Unable to run applications with GUI through x11 forwarding

With your server properly configured, and with X11 server installed on your Windows.

You might need to run export DISPLAY=YOUR_IP:0 on it after connected to the server. The "YOUR_IP" should be change into the IP address of your Windows.

Or, you can try to run startxwin in you Cygwin shell before connect to the server, which will brings up a xterm window for graphical stuff. It will complete the DIPSLAY setting for you automatically, and you should be able to run graphical applications.

You can test the result with xlogo command.

Reference:

http://www.arsc.edu/arsc/knowledge-base/ssh-and-x11-forwarding-us/index.xml
http://cypresslin.web.fc2.com/Memo/M-ENG-SSH.html


Custom Ubuntu Distro - Remastersys - No Set Settings

Remastersys has 2 modes of operation: distribution, and backup. Distribution mode allows you to install packages and add files, but it doesn't save user configuration information. Backup mode saves everything including user configuration changes. The reason your settings aren't there is because they are not system wide, they are user specific, and as such will only appear in your user account. Since settings are done on a per user basis any new user accounts will also get the applications default settings rather than your user's settings. Remastersys cannot help you accomplish your goal because it doesn't alter an applications default settings.

The closest thing you can do would be create a backup so that the pre-included user account on the disc will have settings saved, but as mentioned before newly created additional accounts won't as they get the applications default settings.


Spell did not work for me either.

I was able to make it work by downloading en_US.dic and en_US.aff from sourceforge and using these to overwrite those in the Lyx 2.1.4 installation subfolder ~\Resources\dicts and restarting LyX.

See section 6.14 Spell Checking in the LyX User's Guide.


Whenever I try to call the following command: "notepad /etc/bash.bashrc" from Windows WSL I get an error

NEVER EVER Use a Windows Application to change a WSL file. YOU WILL CORRUPT YOUR DATA.

If you have Windows update 1903 installed (March 2019) you can use Windows File Explorer to access WSL files. However WSL must be running first.

If you want a GUI to edit files try gedit after installing sudo apt install ubuntu-desktop. See this for more information:

What's the easiest way to run GUI apps on Windows Subsystem for Linux as of 2018?


Generally in Graphical desktop environments like xubuntu the desktop environment takes care of mounting external media like USB/DVD for you. FSTAB is used to mount permanent storage like HDD, NFS.

Take the line out of /etc/fstab re the cdrom and then reboot and try just inserting a cd and see if it auto mounts.


I can tell by your screenshot that you are using Unity 2D. All the methods you were using are for Unity.

How to configure Unity 2D.


Usually GTK themes that installed by package manager stored is /usr/share/themes. When you install theme as user, it sets in .themes directory in your home.

You can just copy directory with the same name as theme you like into the same directory in another computer (to /usr/share/themes if you want use it system-wide, or in ~/.themes).

Also you can check the index.theme and look for dependencies. For example this picture shows that the themes "elementary", "eHomosapien", "elementary-monochrome" and "Shere_Khan_X" are also needed for "PinguyOS" theme to work well.

Finally, to change the pointer the following is needed since Ubuntu 10.10:

Edit this file:

gksu gedit /usr/share/icons/default/index.theme

and add the theme you want (see this example:)

Than restart compiz:

compiz --replace


See here for the wiki.ubuntu.com entry on xrandr and how to use it. Basically run xrandr from the terminal and copy the output to create a .xprofile file in your home directory - my .xprofile reads as follows (I have a 1680x1050 monitor connected on VGA1):

xrandr --output VGA-1 --mode 1680x1050

Make the .xprofile file executable then log out and back in again.


Installer stuck at "configuring target system" step

Just to point out: It is possible to install Ubuntu without burning to CD/DVD or via USB drive if you're using a Virtual Machine (eg. VMWare Player/Virtual Box/etc).

I had the same issue where installation froze at "configuring target system". In my case, waiting 12 hours did nothing to resolve the issue. My resolution was to ensure my internet connection worked. I'm at work so I had to go through a proxy, set in the VMWare connection options.

It would seem that internet connectivity was the issue which, if true, is pretty sad that Ubuntu requires this on installation!


Lubuntu alternate and ubuntu minimal install hangs

Sergei. Have you verified MD5sum on your iso? Have you gone over this here?To be honest I have never used the minimal install, but I know that the alternate install has an option to check the disk on the main menu, if so run that as well. Should the MD5sum and the disk check come back good then you will have ruled those out. If these do not solve your issue then what are the specs of your computer? I know you referred to it as "old" but, I have personally used the alternate install iso several times on my Pentium 3 1.2 ghz 512 mb ram desktop and it has never failed (Ubuntu, Xubuntu,and Lubuntu).


I'm just guessing here, because your situation isn't exactly the same, but..

apt-get install python-software-properties

(or perhaps apt-get update python-software-properties)?

That was a pre-requisite step on the 12.04 system I was setting up, but I also got "add-apt-repository: command not found" error, not python errors.  It's those errors which make me think that python is your problem, since that command executed successfully for me once I had installed python-software-properties.

The only other alternative I can come up with--too late to try/fix my own setup--rather than adding an external repository, would be to make everyone's home /home/, and then modify the permissions on all other directories so that the only directory they're allowed to SEE when they read /home/ is "foo"..  They'd still have to navigate into it or you'd have to somehow script changing their CWD after login, but when the initial screen shows nothing but "foo" and is unwritable, it should be fairly low impact to have to "cd foo" or click on the foo folder if using a GUI.  And apparently this is not so simple as I'd imagined, I was thinking of IIS with NTFS permissions when I imagined a permission setting that determines whether a directory can be seen..  I did find that there's an option in vsftpd.conf named "hide_files," which might be able to accomplish this with carefully selected terms (it allows you to specify a regex, but I don't know if you could do something like expand a variable based on the current user's login to make it different for each user...)


Use Noveau NVIDIA driver instead of proprietary driver

I assume you're using Ubuntu 12.10.  If so, open the program Software Sources.  Click the Additional Drivers tab and select the Noveau Driver from the list.  Click the Apply Changes button.  After it's finished, reboot the system and you should be running the open source drivers.


How do we change to dark theme UI in kate editor on ubuntu?

I was earlier using an old version of kate and then I upgraded to the latest version of kate. After upgrading I installed breeze using
sudo apt-get update
sudo apt-get install -y breeze

After installing breeze, went to Settings > Color Scheme > Breeze Dark. This changed the UI to dark theme.


pyvenv vs venv vs python-virtualenv vs virtualenv and python 3

The way to install Python 3.x packages in a Python virtual environment is to create the Python virtual environment using Python 3 virtual environment creator (python3-virtualenv). python3-virtualenv is in the default Ubuntu repositories in Ubuntu 14.10 and later.

Install Python 3.x packages in a Python virtual environment in 16.04 and later

Install Python 3 virtual environment creator

sudo apt install virtualenv python3-virtualenv

Create a Python virtual environment for python3. You can only install python3 packages inside this Python virtual environment. If you also want to install Python 2.x packages, then you need to make another Python virtual environment.

virtualenv -p python3 env
source ./env/bin/activate

The new Python virtual environment for python3 will be created in the env directory which is located in the current directory.
Install Python packages.

cd /path/to/env/ # env is the python3 virtual environment's directory
source bin/activate
python3 -m pip install first-package-name next-package-name last-package-name

This is a new python3 virtual environment with the latest version of pip3, so installing Python packages in it will work great.

Install Python 3.x packages in a Python virtual environment in Ubuntu 14.04

sudo apt-get install virtualenvwrapper
gedit .bashrc

Add the following line to the end of .bashrc.

source /usr/share/virtualenvwrapper/virtualenvwrapper.sh

Save the changes to .bashrc and close gedit. Source your .bashrc for the changes to take effect.

cd
source .bashrc

Create a Python virtual environment for python3. You can only install python3 packages inside this Python virtual environment. If you also want to install Python 2.x packages, then you need to make another Python virtual environment.

mkvirtualenv py3 -p /usr/bin/python3

The new Python virtual environment for python3 will be created in the ~/.virtualenvs/py3 directory. .virtualenvs is a hidden folder.

Install a package.

cd ~/.virtualenvs/py3
source bin/activate
python2 -m pip install package-name


Ubuntu 12.10 boots to black screen after reinstallation in dual boot

You might need to delete Ubuntu from that partition and then re-install it with a bootable USB

You can look online for resources on how to delete Ubuntu while running Windows.


Why is making a Ramdisk for /tmp a good Thing?

As the File System Hierarchy Standard states

  Programs must not assume that any files or directories in /tmp are
  preserved between invocations of the program.

http://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.html#TMPTEMPORARYFILES

So this data need not be kept and probably should be cleared out often. However most modern Linux distributions now map /tmp -> /run/tmp/ instead of some complicated per application exit purging and /run MUST be cleared every boot so this is just easier.

  This directory contains system information data describing the system
  since it was booted.

http://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.html#VARRUNRUNTIMEVARIABLEDATA

Most distributions therefor implement /run (and therefor /tmp -> /run/tmp) as a tmpfs. This ensures any applications that don't cleanup their files in /tmp get purged every boot.


Install 3G Irvine (maybe Huawei) dongle on Ubuntu 12.04

I found a procedure on some Internet forums. It has worked for me with the new Ubuntu 13.10 saucy.

At terminal execute the following

sudo eject sr1
sudo modprobe usbserial vendor=0x20a6 product=0x1106

This will detach the usb_storage device at sr1(cdrom) and enable the usb serial ports for the modem. By some reason this will only work once. If you remove the dongle and connect again the first line will not work.

Also it takes about a minute to the NetworkManager detect the new modem device.
After the detection a new network option like 3g broadband will show up in the connections menu. Enabling it will allow you to create a new connection to your provider.


There are several starting points. Some were pointed out here.

There are also a few nice instructional videos on Youtube. For example this
or even this, while the second is about
 Ensemble, but the syntax is quite similar.

There is also a webinar here:

http://www.brighttalk.com/webcast/6793/39309


How can I delete all partion of my pen drive and create a single volume?

Well my proposed solution might sound harsh and will definitively delete everything on that pen-drive so make sure you use the right path. I write my answer now on that setup seen on your screen-shots.

Open a terminal by pressing ctrl+alt+t.

Then

# like said make sure you use the right path to your stick !!
sudo umount /dev/sdd1
sudo dd if=/dev/zero of=/dev/sdd1 bs=4MB

Let this run for a while (it will take a moment to write zero on 8 GB doing 4 MB steps).

after that nothing should be on that drive anymore and you should be able to start over fresh.


To Upgrade Ubuntu Kernal :

Check your current version of Ubuntu :

$ lsb_release -a

Check your current ke0rnel :

$ uname -mrs

Find Latest Release :

$ sudo apt update
$ apt-cache search linux-generic

Or use :

$ apt-cache search linux-image

Install latest Version :

$ sudo apt install linux-image-4.xx

Reboot :

 $ sudo reboot

Verify the updated version :

$ uname -mrs

Alternatively you can use UKUU:

$ sudo add-apt-repository ppa:teejee2008/ppa
$ sudo apt-get update
$ sudo apt-get install ukuu -y
$ ukuu –help                          # To show commands

Now to use UKUU :

$ ukuu –list
$ xhost +
$ sudo ukuu --install v4.xx.x        # x is the version number you want to install

Reboot and check:

$ reboot
$ uname -r


How to change the owner of the folder named $RECYCLE.BIN in ubuntu 16.04 LTS?

This command will make the current user own the folder and all it's contents:
sudo chown -R $USER <your-folder-name>

Hope it helps!


How to enable Google search for GNOME Shell?

Search buttons for Google and Wikipedia were present in the Activities Overview in earlier versions of GNOME Shell, but it wasn't an actual search provider and didn't integrate very well.

You can try a Wikipedia search provider from https://extensions.gnome.org/extension/512/wikipedia-search-provider/

I haven't seen a Google search provider yet.


How to use a never library on Ubuntu 12.04

Don't worry about the version you installed yourself, you can just simply remove the folder.

How to get to another version, then?

I'd try apt-pinning for installing the package from another source.

There will be a newer package in a PPA or even in another Ubuntu version and with apt-pinning you can make them available.

It has it's limitations, though.

Here you can read more about it.

But please be careful. Especially updating libc6 to a newer version will break your whole system. It happenend to me, too. So make sure that you don't update the main lib of the system, or that libc6 is not part of the updated packages.

I will also post another link, where different "ways" of installing are presented. Take a look here.

But apart from that little flaw apt-pinning works awesome.


A Wacom Intuos 490 is a graphics tablet that plugs into a PC.

The Ubuntu Help pages contain details for connecting these devices to an Ubuntu powered computer.

If you still have problems after following the Help pages, then please [edit] your question to include the specific details of what you have done, and what happens.


Why can't I access directories in my home directory using the command terminal?

Lets break it down:

At first i am at the home directory of the logged in user (indicated by ~ sign), the name of the user is someuser. If you do a pwd you will see the full location where you currently at:

someuser@someuser-home:~$pwd
/home/someuser

Now i want to go back a directory i.e. to the /home directory, as you have typed:

someuser@someuser-home:~$ cd /home
someuser@someuser-home:/home$ pwd
/home

Thats right, i am currently at /home. Now again if i do cd /home/someuser i will go back to where i was previously i.e. /home/someuser:

someuser@someuser-home:/home$ cd /home/someuser
someuser@someuser-home:~$ pwd
/home/someuser

If you want to go some other directory that /home/someuser while you are at /home you need to cd into that directory (given you are permitted to do so). You can do ls to find the subdirectories of /home and then choose our desired one.

someuser@someuser-home:/home$ pwd
/home
someuser@someuser-home:/home$ ls -l
drwxr-xr-x  4 dir           dir          4096 Jun 28  2014 dir
drwxr-xr-x  2 someuser      someuser     4096 Jan 10  2014 someuser
someuser@someuser-home:/home$ cd dir
someuser@someuser-home:/home/dir$ pwd
/home/dir

EDIT:

Now in accordance to what you have said in the comment, you want to check what is inside the directory /home/john/documents/linux-unix. To list a directory i.e. to check what is inside a directory you need ls command, not cd. cd will take you to the destination directory but ls will list the files or directories inside that directory. So to list a directory:

`ls /home/john/documents/linux-unix`

Now as per your Rinzwind's comments i think you are mistaking the case sensitivity of Ubuntu. Ubuntu is case sensitive i.e. Documents and documents are not same. So you can have a directory named Documents and a directory named documents at the same time in you home directory.

someuser@someuser-home:~$ pwd
/home/someuser
someuser@someuser-home:~$ ls -l
drwxr-xr-x  2 someuser someuser    4096 Nov 22  2014 documents
drwxr-xr-x  2 someuser someuser    4096 Sep 29  2013 Documents

Normally /home/someuser/Documents is created during installation. So, as your directory linux-unix was inside /home/john/Documents you need to do:

cd /home/john/Documents/linux-unix

or to list the contents:

ls /home/john/Documents/linux-unix


Keyboard with RGB that requires a Windows program to light up

I made a software that controls the Lenovo Legion Y720 keyboard backlight.
https://github.com/Izurii/Lenovo-Y720-KB-LED-Driver
It's made for Linux and right now it's working with Ubuntu 20.04
Lenovo Y720 KB Controller Releases
You can download and run the latest AppImage and change the keyboard settings or you can download de DEB package and install using sudo dpkg -i package-name.deb in a terminal, the software starts at login so you don't need to open every time you restart your PC, and the global hotkey Fn+space (the same used in Lenovo Nerve Center) is working.


Trying to get conjure 2.6.1 but not getting

Updating the resolution, got it working by below command:

sudo snap refresh conjure-up --edge


Protecting OAuth secrets in App Showdown submissions

Depending on which web service you want to use, the answer is one of those:

1) You can't, period

If the service absolutely requires you to completely protect the token secret, then desktop applications are out of luck. Even closed-source applications can have their binaries examined or be memory dumped during HTTP requests. If the web service enforces such a rigid rule, they are either out of touch with reality or expect only web applications to use their API.

2) Just obfuscate

Some web services are tolerant if you simply don't make the secret immediately available. Just use a simple reversible obfuscation scheme that does not require closing the source.

3) Don't protect at all

You can see here that Google is an example of service that recognizes that full secret protection is a lost battle for desktop apps. For those, you can put the key in the open source and be happy.

So I recommend you to contact the service support and ask in which of those cases you are.


Synaptic Package Manager doesn't launch from the Application Menu

You can fix it by following:

Open terminal (ctrl+alt+T) and execute:

gksudo gedit /usr/share/applications/synaptic.desktop

If gksudo is not installed, you can just install it. It's provided by the gksu  package.

(Or you can run sudo -H gedit instead. But avoid sudo gedit).
Change line Exec=synaptic-pkexec to Exec=gksudo synaptic.
Save file and close text editor.


Setting up Ubuntu and Windows 7 dual boot with preinstalled Windows 7 without Windows CD

The UbuntuLive CD which you can download from the Ubuntu Website will give you the option of installing alongside your existing Windows 7 installation without damaging it.

It's always good to back up your data files, just in case anything goes wrong!


Can anybody read my password protected hard drive files using my hard drive as secondary hard drive?

Yes, they would be able to access the data. If you want to avoid that, you have to encrypt the data. Here is some information how to use the encrypted "Private" folder or to encrypt your home folder: https://help.ubuntu.com/community/EncryptedHome

Here you can find how to encrypt any folder or partition: https://help.ubuntu.com/12.04/serverguide/ecryptfs.html


How to set up Gnash and Epiphany for youtube?

It doesn't seem like it's possible.

When I go to the GNash website and actually look at the example video that is supposed to be working, I don't see anything, but I hear the sound. That means the Gnash is somehow, maybe, working.

But not on youtube.


How to change Ubuntu Mate applications menu icon

The icon is in /usr/share/Numix/24/Places/start-here.png. The same icon is different in Numix if the size is greater than 24.

This is at size 24
This is at size 48


How to disable ssh login for all users except one?

I think you can use the following directive and do not need Match section:

AllowUsers john


Startup disk creater not loading ISO file in 14.04

.iso file is seen by startup disk creator when opening other dialog but never gets selected (its like it does not really recognize this file extension) but this does not happen with all .iso files.
Just rename iso image to img extension
mv imagename.iso imagename.img

This has happened to be on 14.04, 16.04 and 18.04 but I assume is a glitch of the program and not ubuntu.
at least in my case I had to move img to Downloads folder otherwise "Startup disk creator" did not see it
mv imagename.img ~/Downloads/imagename.img

Then open "startup disk creator" and choose appropriate USB (img should be automatically chosen)
For more details on iso and img renaming look in
How to create an .img file from .iso on Ubuntu?


Geometry of USB Memory - heads per cylinder is 124

The built-in Startup Disk Creator application in Ubuntu is good for making all kinds of bootable live USB sticks, not just for making Ubuntu live USBs. Whatever live USB you make with Startup Disk Creator will have no problem booting on Ubuntu or any other platform.


Do I boot from a Live CD now that I'm stuck on grub rescue>

boot your computer on a Ubuntu live-CD or live-USB.

choose "Try Ubuntu"
connect internet
open a new Terminal, then type:

sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get update

Press Enter.
Then type:

sudo apt-get install -y boot-repair && (sudo boot-repair &)

Press Enter


Creating a script to install software after a clean install?

Yes on all 3 questions.

Regarding the last question on settings: you can use package dconf-tools (included in the example) for a lot of them. And gconftool-2 for some others (though that latter one is phased out). I added one line at the bottom of the example. You can search for them like so gsettings list-recursively | grep plugins.power|more. This will show anything related to power settings.

If you need conditional commands you can use &&: {command && command2} will only issue command 2 if command 1 does not fail.

Create a text file and make it executable and add in exectable pieces of code.
Example with some random things I do post install (that includes symlinking my home to a seperate disc (that does not get formatted when re-installing):

# Enable sources, add PPAs and update sources:
sudo sed 's/# deb/deb/' -i /etc/apt/sources.list

sudo add-apt-repository ppa:tiheum/equinox
sudo add-apt-repository ppa:am-monkeyd/nautilus-elementary-ppa
sudo apt-get update
sudo apt-get upgrade

# Symlinking home folders.
cd /discworld2/
mkdir Desktop/ Downloads/ Pictures/ Videos/ Public/ Music/ Templates/ Documents/
cd
rm -rf Desktop/ Downloads/ Pictures/ Videos/ Public/ Music/ Templates/ Documents/
ln -s /discworld2/Desktop/   Desktop
ln -s /discworld2/Documents/ Documents
ln -s /discworld2/Downloads/ Downloads
ln -s /discworld2/Pictures/  Pictures
ln -s /discworld2/Templates/ Templates
ln -s /discworld2/Videos     Videos

# Adding software:
sudo apt-get install -y dconf-tools powertop htop compizconfig-settings-manager deluge vlc smplayer shutter chromium-browser cheese gtk2-engines-equinox faenza-icon-theme equinox-theme

# restart nautilus (req. to activate elementary):
nautilus -q

# remove lock screen

gsettings set org.gnome.desktop.screensaver lock-enabled false

# Altering settings power management (OLD method):

gconftool-2 --set --type string /apps/gnome-power-manager/critical_battery       shutdown
gconftool-2 --set --type bool   /apps/gnome-power-manager/battery_reduce         false
gconftool-2 --set --type bool   /apps/gnome-power-manager/idle_dim_battery       false
gconftool-2 --set --type string /apps/gnome-power-manager/lid_ac                 blank
gconftool-2 --set --type string /apps/gnome-power-manager/lid_battery            blank
gconftool-2 --set --type string /apps/gnome-power-manager/sleep_computer_ac      0
gconftool-2 --set --type string /apps/gnome-power-manager/sleep_computer_battery 0
gconftool-2 --set --type string /apps/gnome-power-manager/power                  interactive


In Nautilus go to Edit > Backgrounds and Emblems > Emblems > Add a New Emblem, type a name and choose an icon:

Close the window, then find and right-click the folder you want to add the new emblem to, and choose Properties. In the Emblems tab and select your new emblem:


Recover the package manager after crash during update

You might wanna try updating system from terminal
open terminal by

Ctrl+Alt+T

code:

sudo apt-get autoremove && sudo apt-get autoclean

sudo apt-get update && sudo apt-get -y upgrade --fix-missing


How do I change Google Chrome's system tray icon?

There are also Chrome icons in /usr/share/icons/hicolor/NxN/apps/google-chrome.png

NxN are various resolutions; you probably need to replace the image in either 22x22 or 24x24.


You can if your BIOS supports booting from usb and if your willing to format that drive.

You can use a program like unetbootin to create the bootable USB. This program lets you select from a whole range of linux distributions to install or just use an iso that youve already downloaded.

Then with the usb plugged into your computer, restart and enter your BIOS setup by holding delete or F10 (it will say on the screen).

If your BIOS supports USB booting the drive will show up in your boot order.


Visual Studio Code is a lightweight but powerful source code editor which runs on your desktop and is available for Linux, macOS and Windows. It comes with built-in support for JavaScript, TypeScript and Node.js and has a rich ecosystem of xtensions for other languages (such as C++, C#, Java, Python, PHP, Go) and runtimes (such as .NET and Unity).
Visual Studio Code is the top upvoted IDE at What are the best IDEs for the Go programming language?. One reason why is that Visual Studio Code has comprehensive support for the Go programming language is shown in the 2nd and 3rd screenshots.
To install Visual Studio Code in all currently supported versions of Ubuntu  open the terminal and type:
sudo snap install code --classic

The Extensions icon is the 5th icon which is highlighted in the vertical panel on the left side of Visual Studio Code. Go (golang.go) extension adds rich Go language support for Visual Studio Code. Code Runner extension runs code snippets or code files for multiple languages including Go in Visual Studio Code. To run a code snippet with Code Runner right-click the code and select Run Code as shown in the below screenshot. The output of the program is shown in the console at the bottom of Visual Studio Code.

Click the Install button to install missing Go analysis tools.


First, make sure you have Sun JAVA installed.  Installing the JDK or the JRE is a sufficient way of doing this.  The JDK might be best.  Read here on how to install it: https://askubuntu.com/questions/5567/how-to-install-the-sun-java-jdk

Then, from the Minecraft site, you will need to download the beta .jar file.  Download it to your Desktop.

Then, in terminal, do the following:

cd /home/username/Desktop
chmod +x minecraft.jar

Replace username with your username that you login to your computer with.

Then right click the Minecraft.jar file, and go into Properties.  Under the "Open With" tab, choose the option button that says "Sun Java Runtime" or similar wording.  Hit the "Close" button.

Finally, double-click the minecraft.jar file.  It should now run the Minecraft client.


Unable to boot Win8 after Ubuntu install

If you have Windows 8 DVD, just boot from DVD and select repair option. This will fix your problem.


MENDELEY - error foreign key constraint failed

I got the answer from the Mendeley team, so I am posting it for completeness.

>

Follow this path: ~/.local/share/data/Mendeley Ltd./Mendeley Desktop/

Look for your SQL file and delete it. It should look like this: youremailaddress@www.mendeley.com.sqlite or delete the entire Mendeley Desktop folder.

Uninstall and reinstall Mendeley Desktop.
Log back in to Mendeley Desktop. Sync your library to re-download your database from the Web.

If this does not help, delete the entire desktop folder.  Please be sure to delete the Mendeley desktop folder and not the Mendeley Ltd folder, since this will just delete the application. Don't worry about deleting the folder as you will regain all your data upon syncing when the application opens.


What are the available browsers for 128 MB of RAM PC?

what i know and close to what you want is midori , midori  is a web browser that aims to be lightweight and fast.. go to ubuntu software center type midori and install it.


Do you mean a cpanel lookalike module ?

I think you can try virtualmin


Error in apt-get update which does not solve after deleting the content of /var/lib/apt/lists/

You seem to be using http://cran.stat.unipd.it - seemingly related to R - as a source. Perhaps their repository URL has changed. However, I looked through http://cran.stat.unipd.it/bin/linux/ubuntu/ and it seems to be fine. Perhaps it's a temporary issue with that mirror, and you could try another mirror, or wait for some time and re-enable that one.


gedit put BOLD text with Yellow Background on a script comment line

Not just TODO but FIXME and XXX will also highlight.

see this file line no 107 and line no 184

/usr/share/gtksourceview-3.0/language-specs/def.lang

You can add stings of your choice like DATE:

Open def.lang file and add DATE at line 184 as shown below:

For changes to take place CLOSE your already opened document and reopen.
Now add #DATE in your document and it will highlight.


12.04 precise HDMI not working on ATI Radeon

I had a problem on my Samsung FullHD-tv that the tv showed me every time "Unsupported Resolution" under the 1080p mode, but when I switched to 1080i (1920*1080*30Hz) all worked fine.


Install Mac OS X 10.9 as a virtual machine

I wanted to share a video, but it wouldn't be good to put the link here, so the link could be censored.

No, you need to unify the empty disk to the Ubuntu's HHD. VMWare to Virtualbox can't detect the HHDs or the volumes. But if you have enough Ubuntu's HDD, don't unify, firstly install the virtual machine on Ubuntu's HDD, then, move it to the empty disk.

But search "OS X Snow Leopard" at Web UPD8 and you'll find that article. Google at Youtube "How to install Mac OS X Snow Leopard on Ubuntu".

I recommend Virtualbox as that article and the video suggested, so it's very easy to be installed. But VMWare is another good idea.

If you want to use OS X 10.9... firstly you need to install OS X Snow Leopard on a virtual machine and update to 10.6.8, and at 10.6.8, download OS X 10.10 (it's free) (unfortunately OS X 10.9 isn't available).

I recommend you to visit and ask for help at the InsanelyMac (they're good people and help a lot the people to make Hackintosh), but before, I'll give you a tip: please, don't cite iAthos and TonyMacOSX86, so that forum doesn't support them.

Good luck!


Ubuntu 14.04.02 Live USB boots to black sceen

I've seen a case of Ubuntu 14.04.2 on VirtualBox, that boots and automatically switches to tty3, which is empty.

You can test, if it's the same problem by waiting 20-40 seconds and press ALT+F1, to switch to tty1. If you see login prompt there, it's the same problem. If not, it's something else.


Problem with old genius digital drawing tablet, ubuntu 16.10

The problem

There is a bug on xserver-xorg-input-evdev-1:2.10.2 that specifically affect pressure, it is not reported from kernel evdev to xserver-xorg-evdev:

https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-input-evdev/+bug/1639337

Acording to one of the comments, the solution is to downgrade to xserver-xorg-input-evdev-1:2.10.1, please help by adding yourself as one of the affected users on the list, so this can be properly corrected (the package being updated to a newer version).

How to downgrade the package

Get the older package here: http://packages.ubuntu.com/xenial/xserver-xorg-input-evdev (if x86 64 bits it is amd64, if x86 32 bits, i386)

After that you should open the terminal and do:

sudo dpkg --force-all -i path/to/xserver-xorg-input-evdev_2.10.1-1ubuntu2_amd64.deb.deb

adjusting the path to the correct folder. Finaly, force the package to not upgrade:

sudo apt-mark hold xserver-xorg-input-evdev

You will need to pay attention to this bug, so you remove the mark when it is solved (on the same bug link find where to put yourself on the mailing list for changes)

  Again, It is not the best solution, specially at this case there is no visible counter effects, but this kind of forceful downgrade generally result on many broken packages if not an broken system , so please consider going to the bug report and add yourself to the list of affected persons so this bug gain more relevance and get corrected quicker.


Install Ubuntu and Windows on the same pc

(a) For a dual boot machine, it is recommended that you install Windows first, with sufficient space for a blank partition, where Ubuntu would be installed.

(b) In case you wish to have a Ubuntu based machine, install Ubuntu first, and then install Virtualbox. Inside virtualbox, install your legal copy of Windows.


Stopping touchpad clicks registering as right-clicks when there's another finger already on the pad

Turns out libinput Click Method Enabled was the setting I was looking for in xinput --list-props

The previous setting,0 1, would determine the click type based upon how many fingers were on the pad.

Changing to 1 0 determines click type by the area of the pad that is clicked (left, middle, right), so a click is always a left click as long as it's on the left side of the pad.


Common Desktop Login via Network (like AD for Windows)

You can use OpenLDAP for authentication and nfs in combination with automount for mounting their home directory to the desktop.

Another possibility is to use the LTSP server project to run all the application from a server and run only thin clients. Which solution is the best, depends on your particular requirements.


I'm also using a Toshiba Satellite model and had laptop heating issues recently. I suspected it was due to CPU running at very high speeds. I installed the indicator-cpufreq that allows you to set your CPU profile and almost always kept it in powersave mode (It gives you an indicator in the top ubuntu panel):

sudo apt-get install indicator-cpufreq

Since then, not only was my heating problem solved, but the fan noise also disappeared as a bonus!


Is it possible to have Nautilus show hidden files except for one specific folder?

This is not possible. By design, showing or hiding files in Files (nautilus) is a global setting, immediately affecting all windows.

In past times, it was a per-window setting. It probably still works like this in forked versions of nautilus, such as Nemo (Cinnamon desktop) or Caja (Mate desktop) and probably other file managers.

Thus, you may not be able to adapt the file manager itself. Either you may need to move away from it, or change your habits. You may want to learn to work without hidden files shown. It will reduce the clutter. In normal working circumstances, there is not much point of having the hidden files visible all the time. That is also why the feature is there: to have files present in a convenient location and at the same time avoiding to have to see them all the time. You only need to see these occasionally, and then they are just a keypress, Ctrl+h, away.


For the first drive use:

udisksctl unmount -b /dev/sr0

For the second drive:

udisksctl unmount -b /dev/sr1


Would upgrading from 12.04 to 12.10 break bumblebee

I am using 12.10 with bumblebee and it works fine. I reinstalled my system instead of upgrading. I guess you installed bumblebee using the ppa. The ppa will be deactivated during the upgrade process. Take a look at this question to see how to re-enable them. After you have done so, run:

sudo apt-get update
sudo apt-get upgrade

This should update bumblebee to the latest version available for 12.10.


How can I type accented characters like ë?

Often this is easier with the compose key. With that configured you use key combos to get the special characters. For instance:

For ë you press Compose+", e.
For ẽ you press Compose+~, e.
For ô you press Compose+^, o.
For á you press Compose+', a.
For à you press Compose+`, a.
For € you press Compose+=, e.
For £ you press Compose+-, l.

Note that you do not have to hold down the compose key; just press each key in order.

To set the compose key go to System -> Preferences -> Keyboard, then Layouts -> Options. Open up Compose Key Position and choose a key. I use Right-Alt.


How do I get proprietary Broadcom drivers to work after installation?

It seems that there is some problem occurred when you installed Wireless Broadcom 802.11 driver. You can give a try to followings:

Open a terminal and execute following commands:

$ sudo (jockey-gtk &)
$ sudo update-grub
$ sudo update-initramfs -u

jockey-gtk will automatically searches all available drivers and try to fix it. Then restart your system.
Try to reconfigure installed Broadcom Wireless Driver

$ sudo dpkg-reconfigure bcmwl-kernel-source

if it still doesn't work then re-install it by completely removing it:

$ sudo apt-get autoremove bcmwl-kernel-source
$ sudo apt-get --purge remove bcmwl-kernel-source
$ sudo apt-get install bcmwl-kernel-source

Try to update your system, sometimes updating fixes a lot of issues. Update your system after removing any broken packages, residual unused packages, execute these commands:

$ sudo apt-get autoremove
$ sudo apt-get autoclean
$ sudo apt-get install
$ sudo apt-get update
$ sudo apt-get upgrade

I hope any of these steps work for you. Reply if something goes wrong..


Make gnome-screenshot ignore XDG_PICTURES_DIR

Gnome developer has changed the way the schema behaves,  you may see the bugzilla page regarding the whole ordeal → https://bugzilla.gnome.org/show_bug.cgi?id=699642.

However you can install Screenshot Locations extension to achieve exactly what you want, with the extension installed— you can change the default directory to save your screenshot seamlessly.

Another workaround to this would be disabling the shortcuts in the Keyboard Shortcuts, then add new ones which uses gnome-screenshot command. This also works and still respect the auto-save-directory schema.


How do I call the Ubuntu system to open or save a file dialog box like Windows

You can do it with a Gtk.FileChooserDialog

Gtk.FileChooserDialog Class

  Gtk.FileChooserDialog is a dialog box suitable for use with
  "File/Open" or "File/Save as" commands. This widget works by putting a
  Gtk.FileChooserWidget inside a Gtk.Dialog. It exposes the
  Gtk.FileChooser interface, so you can use all of the Gtk.FileChooser
  functions on the file chooser dialog as well as those for Gtk.Dialog.

public class MainWindow: Gtk.Window {

    protected virtual void OnBtnLoadFileClicked(object sender, System.EventArgs e)
    {
        Gtk.FileChooserDialog fc=
        new Gtk.FileChooserDialog("Choose the file to open",
                                    this,
                                    FileChooserAction.Open,
                                    "Cancel",ResponseType.Cancel,
                                    "Open",ResponseType.Accept);

        if (fc.Run() == (int)ResponseType.Accept)
        {
            System.IO.FileStream file=System.IO.File.OpenRead(fc.Filename);
            file.Close();
        }
        //Don't forget to call Destroy() or the FileChooserDialog window won't get closed.
        fc.Destroy();
    }

Read more about here: http://docs.go-mono.com/index.aspx?link=T%3AGtk.FileChooserDialog


The USB i used to transfer the file over to my laptop was corrupt as I disconnected it before it said it was safe to remove. So I downloaded 18.04 instead of 19.4, burned to DVD and now it's installing


Installing Ubuntu 13.04 on VirtualBox gives an internal error at the start

Most system requirements specifications I've seen indicate a minimum of 512MB of RAM for the desktop edition, for example here:

System Requirements

You may first decide to increase the amount of RAM given to the virtual machine if possible since you've allocated 256MB only.

You might also consider giving it the maximum possible video RAM of 128 MB (since it was a Compiz failure the 12MB you allocated might also be insufficient).

Change those settings first and see if it works. If not, you can use the Ctrl+Alt+F1-6 combination to open a Linux virtual terminal to debug if necessary. (This is of course assuming you're unable to use the graphical interface at all, otherwise you could just open a terminal from Unity.)


unable to install LAN Messenger 1.2.32 ubuntu 14.04.3

I found the answer using this post:

  sudo  apt-get install libgstreamer-plugins-base0.10-0:i386


Ubuntu 10.04 server delay when POST to mySQL

As I mentioned in the comments, I see no reason to believe MySQL is the bottleneck here, but I do think the webserver configuration can cause this.

Installing a regular LAMP setup done by for example apt-get install lamp-server^, will install PHP as an Apache module and pull in the prefork MPM. By default, this only starts with a limited number of workers (forks) to handle incoming connections. Any new connections will simply not be processed (though not refused). So, I think what you're seeing is simply that the "pool" of workers is to small to handle all the connections.

An error similar to this one will probably be in your Apache error logs somewhere when hitting this limit:

[error] server reached MaxClients setting, consider raising the MaxClients setting

To configure the prefork MPM in Apache, you can see the current values in /etc/apache2/apache2.conf:

# prefork MPM
# StartServers: number of server processes to start
# MinSpareServers: minimum number of server processes which are kept spare
# MaxSpareServers: maximum number of server processes which are kept spare
# MaxClients: maximum number of server processes allowed to start
# MaxRequestsPerChild: maximum number of requests a server process serves
<IfModule mpm_prefork_module>
    StartServers          5
    MinSpareServers       5
    MaxSpareServers      10
    MaxClients          150
    MaxRequestsPerChild   0
</IfModule>

In order to change this, I'd recommend to create a new file in /etc/apache2/conf.d, e.g. prefork-mpm-tuning.conf and just "overload" the settings from their defaults (and restart Apache):

<IfModule mpm_prefork_module>
    StartServers          20      # |-- important to increase
    MinSpareServers       20      # |
    MaxSpareServers       50
    MaxClients           70       # too high will get you out-of-memory here
    MaxRequestsPerChild   0
</IfModule>

Important note here is that Apache only scales up per second, starting with only one (hardcoded, not configurable) and never scales down unless you explicitly configure it to. As explained in the Apache documentation on performance tuning:

  If the machine is busy spawning children it can't service requests. But it has such a drastic effect on the perceived performance of Apache that it had to be replaced. As of Apache 1.3, the code will relax the one-per-second rule. It will spawn one, wait a second, then spawn two, wait a second, then spawn four, and it will continue exponentially until it is spawning 32 children per second. It will stop whenever it satisfies the MinSpareServers setting.

  This appears to be responsive enough that it's almost unnecessary to twiddle the MinSpareServers, MaxSpareServers and StartServers knobs. When more than 4 children are spawned per second, a message will be emitted to the ErrorLog. If you see a lot of these errors then consider tuning these settings. Use the mod_status output as a guide.

While the last paragraph may apply to general cases, I find it very confusing in testing that Apache seems unresponsive after restarting. For this reason my recommendation is to raise the StartServers setting.

So, to summarize:

You probably want to increase the StartServers to accept all the subsequent connections you fire from the clients. Apache's prefork MPM is not very dynamic worker - to be able to have it perform well with a lot of simultaneous connections, you'll need to simply start a lot.
Allow it to allocate enough memory (roughly 20MB per fork in practice). Yes you'll need loads of it just to serve 100 concurrent visitors in this design. (look at PHP-FPM if you need more performance with less memory)
Limit the MaxClients to prevent Apache to claim all memory of the server and crash it. Do math and testing here.
Setting StartServers too low to save memory while maintaining a larger MaxClients is a bad thing: your site will appear to be slow for the one-per-second reason and memory usage will grow later anyway. This will happen then.

References:

Apache prefork MPM tuning on a low-memory machine
Apache Performance Tuning
Optimal values for ServerLimit, MaxClients, MaxRequestsPerChild directives


How can I debug intermittent high pings?

If it is an ISP network problem, you can try using tracepath, it shows you all the network segments.

Usually it is used for MTU measurement, but it contains the RTT of each of the network segments.


How do I enable font anti-aliasing in Wine?

The easiest way is through winetricks

mkdir ~/bin
cd ~/bin
wget http://winetricks.org/winetricks
chmod +x ./winetricks

winetricks fontsmooth-rgb

In newer version of winetricks the command to use is

winetricks settings fontsmooth=rgb

There are other LCD pixel orders available. You can read about them and the rest of the impressive winetricks feature list on its WineHQ site.


If your system restart forcefully then pid file may be generated cant start at startup so you need to remove it once
If you are using Xampp on ubuntu then follow below steps:
goto /opt/lampp/logs/
then run below command
sudo rm -rf httpd.pid

then goto /opt/var/mysql/
then run below command
sudo rm -rf system hostname.err

and restart service
sudo /opt/lampp/lampp restart

That's it


SOLVED: moved the command back one level...

root@blackserver:/sys/devices/pci0000:00/0000:00:1a.0# echo -n 1 > remove

dmesg output now...

[65207.355668] ehci-pci 0000:00:1a.0: remove, state 4
[65207.355680] usb usb3: USB disconnect, device number 1
[65207.355682] usb 3-1: USB disconnect, device number 2
[65207.360110] ehci-pci 0000:00:1a.0: USB bus 3 deregistered
[65207.475341] iommu: Removing device 0000:00:1a.0 from group 7

No other error messages and the USB controller is no longer listed in lspci or devices shown in lsusb.


Why should I jump from Windows to Ubuntu

Welcome to Ask Ubuntu! No, you have a team of specialists willing to help right here. If Sage is essential to your business, the parts of the company that require it should stick with Windows. The other parts of the company should do just fine with Ubuntu, Ubuntu has a reputation of being built from the ground up to be user-friendly. Apart from the obvious cost savings, for more reasons on why Ubuntu is better then Windows in many cases for basic everyday business tasks, see my post at Why should my business choose Ubuntu? . Hope that helps! Leave a comment if you have any more questions.


What happens when shutdown/reboot is executed?

Until 15.04 upstart was used for this, then being replaced by systemd.

Used until Ubuntu 15.04: upstart
When you press the shutdown button or execute shutdown +0 in a terminal, upstart executes every script in /etc/rc0.d in alphabetical order.
When you press the reboot button or execute shutdown -r +0 in a terminal, upstart executes every script in /etc/rc6.d in alphabetical order.
Edit: Note that the +0 in the above commands indicates the number of minutes to wait prior to taking the requested action and is equivalent to now. If you have other users on the system it would be prudent to increase this value to allow them time to save their work.
Both directories hold only symlinks whose targets are located in
/etc/init.d/ though.
For more information see /etc/init.d/README and man init.
Used from Ubuntu 15.04 on: systemd
Here some links concerning systemd:

“SystemdForUpstartUsers” on wiki.ubuntu.com
exhaustive article “Understanding Systemd Units and Unit Files”


Problem with screenlets and permissions?

I suggest to make sure all files and directory under you home belong to you. Run this command

find ~ ! -user $USER -o ! -group $USER

to check this. This other command to repair

sudo chown -R $USER:$USER ~

Then retry screenlets-manager. If you have the same result, post the output of

ls -ld ~/ ~/.config/ ~/.config/autostart/

As a note, never use sudo when it is not required.


How can the login greeter drums be turned off in Ubuntu 15.10?

With one command in your terminal, disable with

gsettings set com.canonical.unity-greeter play-ready-sound "false"

and/or enable with

gsettings set com.canonical.unity-greeter play-ready-sound "true"

Or install dconf-editor

sudo apt-get install dconf-editor

and run

dconf-editor

Navigate to

com.canonical.unity-greeter

in the left pane. In the right pane you will see play-ready-sound

and you could do the same in a GUI.