Terminal TTY Ctrl-Alt-F# not working, only prints junk characters I'm not sure what I pressed to mess this up. I was on tty1, but it doesn't look like I'm on tty1 anymore. When I press any key on the terminal it just prints weird letters. Pressing Ctrl-Alt-F1 through F7 also just prints characters.

Multiple times I tried typing in reset and [Enter] into the terminal, but it isn't fixing the problem. I tried typing Ctrl-q then reset, but still just crazy characters.

I'm pretty sure the kernel is still running correctly because, before this happened, I started a very large file transfer from a host computer to this computer. The files still appear to be copying correctly from the host computer.

https://i96.photobucket.com/albums/l169/extralifestar/bad_term.png

Anyway to restore a system like this?

try Ctrl+Alt+F2 and see if that works for what you're doing. Sometimes it appears like the x-session is using tty1 for some things. so see if you can just do it on 2. or just type in your username and password and after it logs in it should clear all that text on tty1.


can't make bootable usb on mac I've been trying to do this since yesterday, following the instructions given on ubuntu.com's official page here:

http://www.ubuntu.com/download/help/create-a-usb-stick-on-mac-osx

I can complete every step without error. However, when restarting the mac, the flash drive simply reports 'missing operating system, press any key...'. From there, there's nothing I can do except a hard reset.

I've tried Unetbootin, but that won't create a usb that's bootable from a mac.

edit: I've also fixed the partition tables with rEFIt, but still no joy.

Any suggestions?

Here's my own answer:

OK, so I figured it out, largely thanks to this extended thread on macforums

http://forums.macrumors.com/showthread.php?t=1329407

However, I'm going to offer a summarized version here. Whoever's responsible for the ubuntu page on this (the one I linked to in my OP) really should get it changed. Those instructions just don't work.

Here's what you need:

Download Ubuntu.iso
Download and install rEFIt from here http://refit.sourceforge.net
Download and install the app UNetbootin from here: http://unetbootin.sourceforge.net
A 4GB Flash Drive formatted to FAT32
free space on an internal or external disk to boot from and install too.

Create flash drive files:
Start up UNetbootin. Choose the ubuntu iso as the source and the flash drive as the destination. When that's finished you'll get a warning that the USB is not bootable on a mac. That's expected.

Create partitions on hard disk:
Open Disk Utility and choose the internal or external disk that you're going to use. Create a 2GB partition on it, formatted to FAT32. Create another partition (you can choose FAT32 for this too) the same size as you want your final install to be (I have a 750GB internal disk on my mac, so I gave ubuntu 100GB of that).

Get device names:
Open Terminal.app on your mac and copy/paste this command (you can type it, but there'll be some more complex commands later that you might want to cut and paste to avoid errors)

diskutil list

From the output, identify both the flash drive and the 2gb partition. They will have names such as /dev/disk1s1 and dev/disk0s4 for example. Make sure you pick the right name, or you could end up doing some damage.

Dismount devices:
Open Disk Utility.app, and click on the flash drive in the sidepanel. Hit the 'dismount' button in the taskbar above. Do the same for the 2gb internal partition.

Move files from flash drive to HD partition:
Copy and paste this into Terminal, but DO NOT press 'return':

sudo dd if=/dev/disk1s1 of=/dev/rdisk0s4

Change the device names to match those you found in step 3. The first device name is source (the flash drive), the second one is the destination (the 2gb fat partition on your internal disk). Notice that I've added an 'r' before 'disk' on the output device. That's deliberate and you should make sure you add it too, as it speeds up the copy process considerably.

Double check that line is correct, then when you're ready, press 'return' and enter your admin password (it'll be invisible when you type it).

Remove flash drive:
When that eventually completes, dismount and remove the flash drive. You don't need it anymore.

Fix partition tables:
Restart your mac with the option key held down. From the rEFIt menu, choose 'sync partition tables'. Confirm with 'y' and exit. Then choose 'restart' from the rEFImenu.

Start up ubuntu live CD:
You should now see the Penguin logo. Click on it to start the Ubunutu Live CD.

Make a bootable USB for Mac.
Go to GParted in Linux on a PC->Device->Create partition table->In the dropdown box choose Mac->Format USB to FAT32->Use USB writer to write to USB. I tried USB flash drives and they didn't work.

A 15-year-old IDE HDD in a USB hard drive caddy worked the first time. USB flash drives didn't make a Mac partition table, but the old HDD in a USB external hard drive enclosure did. Plug in the USB caddy->Turn on the MAC and when you hear the sound push and hold the Option key and the USB will appear. Click on USB->It will load->Then install Linux on the MAC hard drive using the USB HDD.


How to make man pages? I know how to make commands(scripts) in Linux.

I would like to know if I could make man pages for the commands?

Google is your friend

http://www.cyberciti.biz/faq/linux-unix-creating-a-manpage/

This lays out in detail what is required. You will need to use sudo to create the pages. Use the built in editor like vim


Windows 10 Creator Update removed all signs of GRUB So I stupidly was too lazy to disable Windows 10 updates. The creator's update came and hit me, and after it was finished GRUB seems to have disappeared. The only boot device that shows up in my boot manager or BIOS is the Windows Boot Manager.

In Windows, I can still see my Linux partition listed as a healthy, primary partition. However, running test-disk from Windows lists that same partition as a Microsoft Data partition (MS Data) which definitely can't be right. I tried using test-disk to set the partition type to Linux Reserved (there's no option for just "Linux" as I've seen in some screenshots) but GRUB is still gone. I don't currently have access to a USB and can't create a live disk.

The only other partitions that show up in test-disk are an EFI system partition, a recovery partition, and my Windows partition (which is getting deleted as soon as I have Ubuntu back). I'm pretty sure both the EFI and recovery partitions are Windows related. I'm currently running a deep search in test-disk in case anything else is missing, but in the meantime is there anything that I can do to get Ubuntu back?

I'm not familiar with what this specific Windows update does; however, there are several possible things that might have happened, as explained in these questions and answers:

Buggy EFI loses boot settings:
efibootmanager -o changes are lost on reboot
Windows 8 removes GRUB as default boot manager:
Windows 8 removes Grub as default boot manager
Generic return of GRUB as default boot manager:
How can I repair grub? (How to get Ubuntu back after installing Windows?)

You may be able to fix the problem with EasyUEFI in Windows, or with bcdedit if that fails. In a worst-case scenario, you may need to completely reinstall GRUB with Boot Repair (or install another boot loader entirely).

Note that modern EFI-based computers don't boot disks per se, at least not in the same way that BIOS-based computers do. Instead, EFI booting is controlled by files on the EFI System Partition (ESP), with entries in NVRAM that point to specific files. (There can also be boot loaders stored on devices like network cards for network booting; and a standardized fallback filename is used to boot from external media and, when all else fails, from an internal hard disk.)

DO NOT use TestDisk in this situation! In all probability, it will be useless at best and could cause much worse problems if you make a mistake with it! TestDisk is useful for correcting partitioning disasters (like accidentally wiping out a partition table with fdisk, gdisk, parted, dd, etc.), but you've presented no evidence that this is the type of problem you're having.

I installed a hot swap drive caddy with two drive slots, each with its own power switch. I just turn off windows 10 so it can't hijack the Ubuntu bootloader.


How to install MyOpenLab on ubuntu 18.04 I have been trying to install MyOpenLab on ubuntu 18.04. It is freeware alternative to LabView. I found that it required java to run so I installed the java through the terminal. Now when I try to open MyOpenLab through the terminal, I am greeted with the following message.

Can someone please help me with my installation. Thanks.

EDIT: I downloaded the software MyOpenLab from the website myopenlab.org. It was downloaded to my Downloads folder. I then extracted it in the same directory.

I then right-clicked the file and set permissions to read and write and then selected the option "Allow executing file as program."

After that, I opened a terminal in the same directory and entered the command "./start_linux".

The program name then appeared and it asked me about the license agreement. I gave proceed and then it asked me for the path for user defined elements. After selecting the path and clicking on next, I was greeted with the errors and warning.

Also the version of my java are as follows. I obtained them with the command "java --version" at the terminal:

java version "10.0.2" 2018-07-17
Java(TM) SE Runtime Environment 18.3 (build 10.0.2+13)
Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10.0.2+13, mixed mode)

Please help me out with the installation process as it is very important.

On my Ubuntu 18.04.1 LTS I did the following:

cd ~/Downloads
wget https://myopenlab.org/distribution_linux_3.11.0.zip
unzip distribution_linux_3.11.0.zip -d distribution_linux_3.11.0
cd distribution_linux_3.11.0
sh ./start_linux

and got the same error as you have.

Then I installed OpenJDK 8

sudo apt-get install openjdk-8-jre

and set it as default system VM:

sudo update-java-alternatives --set \
java-1.8.0-openjdk-$(dpkg --print-architecture)

then tried to launch it again:

sh start_linux

and MyOpenLab launches normally

Notes:
1. I have never used this software. Just wanted to help you. Thank you for your finding!
2. On Ubuntu 16.04 LTS Xenial Xerus it runs without any special actions (as it uses openjdk-8 by default) .

The following worked in Ubuntu 19.10 based on your suggestion.

sudo apt install openjdk-8-jre libcanberra-gtk-module libcanberra-gtk3-module
sudo update-java-alternatives --set java-1.8.0-openjdk-$(dpkg --print-architecture)
sh start_linux


Ubuntu 12.04 Network Manager: unable to save manual setting to set up a static ip I am fairly familiar with setting up servers, and ubuntu is generally my flavor of choice, but I just installed 12.04 desktop and I am seeing some behavior in network manager that is really puzzling.  The network connection works fine if I leave it set on dhcp, but I would like a static IP address for my new web server.  When I go into network manager and edit the connection for the one and only NIC I can select MANUAL from the dropdown menu but as soon as I do the Save button becomes greyed out.  Even after filling out all fields for the connection it is still grey and I am unable to save the static IP connection information.  Any thoughts would be greatly appreciated.  I'm hoping there is just some new setting that I am unaware of....

On another note, if I stop the network manager and go edit the interfaces file (and the appropriate hosts/routes/dns files), I do get a static ip address assigned and I can contact my server from the outside, however, the server cannot find the internet.  Can't ping even its own ip...  I can ping the loopback interface though.

I'm really confused on this one.   Hoping someone can offer some help.

Do not press the Add button after entering Gateway IP address. :)

Found out this the hard way:
You have to press Add the first time, to start entering the IP, but when finished - just press enter.

If you do press Add a second time, you make a new address entry and are not allowed by the GUI to save. Select the empty second line and click the Delete button in the GUI to remove it.

This is done to make it possible to enter more than one IP on the interface, but it definitivly was not obvious to me because of the minimalistic IP entry box you have to scroll in..

It is very simple. After filling up all necessary information you only press enter, then you can see save option is enabled.


How to start XAMPP in my browser after installing it successfully I followed this link to install XAMPP on my machine: XAMMP for Linux. I can't open XAMPP in my browser, but I'm getting the 404 errror i.e

Not Found

The requested URL /xampp/index.php was not found on this server.
Apache/2.2.20 (Ubuntu) Server at localhost Port 80

Can anyone help me to find out the error.

The command for starting the server is:

$ sudo /opt/lampp/lampp start

Source here:

apache friends - xampp for linux

use this command

cd /opt/lampp
cd /opt/lampp chmod +x manager-linux-x64.run
cd /opt/lampp ./


Ubuntu freezes after sleep I am running Ubuntu 14.04 on a HP Z230 with an Nvidia NVS 315 video card.
After the system goes to sleep and wakes up again, the screen is black and stays that way. The only way to recover I found is to restart the system.

I figured that this could be a problem with the graphics driver. An NVS card is not really mainstream. So, I downloaded a linux driver from Nvidia (NVIDIA-Linux-x86_64-346.59.run). I figured out how to shutdown lightdm (otherwise there was a complaint about a running X server), but then the script complained that the preinstall script did not complete succesfully. I didn't think it was wise to continue. That is where I am stuck.

Any idea if the graphics driver is the problem? Or should I look somewhere else?

That sounds like a similar problem I had when I updated my kernel.
The fix is described in detail here.

The proposed solution - fixing the problem on my computer

First, make a copy of your xorg.conf

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.BAK

You may need also to install linux headers first.

sudo apt-get install linux-headers-generic

Install fglrx with hardware acceleration

sudo apt-get install fglrx xvba-va-driver libva-glx1 libva-egl1 vainfo

Generate a fresh xorg.conf before rebooting

sudo amdconfig --initial

As a result, my problem was solved and the "Sleep Mode" works without problems.


Ubuntu 18.04: Earphones not working No sound via headphones (headset)

I've recently started using Ubuntu (Dual boot with Windows 10)
The earphone works on other devices/Windows without any issues.
I've even tried to not boot up with earphones plugged in.
Laptop: ASUS S56C
The internal speakers work fine.

ALSA information (alsa-info-script): https://hastebin.com/oyuvihecof.scala
alsa-base.conf: https://hastebin.com/azeqeroqid.pl

Left mouse click on sound icon and select "sound settings".
There you can select proper output device and test it.

Just you have to select the sound output, go to "settings" > "sound" > and select your headphones.
As simple as that.


Laptop screen doesn't work after standby - hit or miss I have an Acer Aspire 5750 and if i let my computer sit for 4hrs - 48 hrs, when i open up the laptop lid, my screen is black. The computer is still on, but it won't wake up.

I use Ctrl+Alt+L to lock the computer.

Any help will be appreciated

edit*

this computer has the 2nd gen intel core i5 sandybridge integrated graphics. I had the same problem on 12.04 and 12.10.

Have you tried to change brightness (press the brightness up button)?

I can't find the links right now to post here, but there are reports that in some laptops when opening the screen lid again the brightness is minimum, in some cases it's like the screen is black. Pressing the brightness up solves in those cases.

Also there are scripts to automatically turn brightness up when keyboard shortcuts are not available or do not work.

I have had a similar issue it was fixed by installing my GPU drivers from the manufacturer. But I went to my laptop manufacturer and found a complete linux driver pack with rpm and autoconf downloads.

Here is the link to the drivers page for your laptop but they have only Windows drivers. I also could not find third party linux drivers for your laptop. You probably have mesa nut it is a gnu compatible version of openGL I would recommend updating/installing other packages for mesa.

Sorry I could not be of further assistance.

okay lucio this is an unconventional fix but you could change this:

GRUB_CMDLINE_LINUX=""

to this:

GRUB_CMDLINE_LINUX="quiet splash acpi_osi=Linux acpi_backlight=vendor"

in the file /etc/default/grub, then:

sudo update-grub

this adds brightness adjustment but still no fix for the screen to turn on. it seems this is a very common issue with acer aspire series.


Where is the .Trash folder? Using Ubuntu 11.10, I accidentally deleted a file that was approximately 700 MB. I tried to find it in the in following locations, but couldn't:

/home/user/.local/share
/home/user/ <-- there was no folder .Trash
/home/user/Desktop/ <-- there was no folder .Trash

So where did .Trash go in Ubuntu 11.10 onward? I use the Gnome environment.

Your trash directory is most likely at:

/home/$USER/.local/share/Trash

If you deleted something as root (e.g. deleted a file using Nautilus invoked via gksu), it is at:

/root/.local/share/Trash

(In general, according to Freedesktop.org specifications[1][2], the "home trash" directory is at $XDG_DATA_HOME/Trash, and $XDG_DATA_HOME in turn defaults to $HOME/.local/share.)

To see .local in your home folder using the file manager, select Show Hidden Files from the View menu or just type Ctrl+H.

The Trash directory is first created when a user deletes a file. Within Trash there are three subdirectories:

files, where the deleted files are stored until the trash is emptied
info, which stores information on where the files once were and when they were deleted
expunged, to which files are briefly moved when the trash is emptied (but may contain some owned by other users from directories you deleted).

Note that using the rm command in a terminal or the Shift+Delete key combination in the file manager will permanently delete your file instead of moving it to the trash.

Explore the folder, and there you'll see the trash button:


Dual boot MacBook with Ubuntu 13.04, 32-bit Please how can I dual boot Ubuntu 13.04 on my MacBook running Mac OS X 10.5.8 with the following specs:

Model Name: MacBook
  Model Identifier: MacBook5,2
  Processor Name: Intel Core 2 Duo
  Processor Speed: 2.13 GHz
  Number of Processors: 1
  Total Number of Cores: 2
  L2 Cache: 3MB
  Memory: 2GB
  Bus Speed:    1.07 GHz
  Boot ROM Version: MB52.0088.B05
  SMC Version (system): 1.38f5
  Serial Number (system): W89214SE9GU
  Hardware UUID:    D0110864-A751-56AF-8BB3-BBA03A9E93FA
  Sudden Motion Sensor:
  State:    Enabled

I enjoyed using Ubuntu on my Dell notebook, but I don't have it anymore plus I am new to Mac and would love to have Ubuntu running side by side with my MacBook. I would appreciate it greatly if anyone could assist me to achieve this.

You dual boot Ubuntu by using boot camp. Here is a video on how to use boot camp on your mac. link


Lenovo T60P with 4GB of RAM, Ubuntu 11.04 and 11.10 only see 3GB I have a Lenovo ThinkPad T60P with 4GB of memory (BIOS sees all 4GB RAM).  I have installed Ubuntu 11.04 and 11.10 and both are only recognizing 3GB RAM. Please advise.

Thanks.

Updates

Used 32bit ver for both 11.04 and 11.10. Just installed 11.10 64 bit and machine now only sees 2.9 gb.

Intel Core 2 Duo Processor T7600

ThinkPad-T60p:~$ uname -a Linux ThinkPad-T60p 3.0.0-14-generic
 #23-Ubuntu SMP Mon Nov 21 20:28:43 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

flags: fpu vme de pse tsc msr PAE mce cx8 apic  etc, etc...

4GB of Crucial RAM, memory test Passed. Current BIOS is 2.27 dated 3/21/11

Sending memory back to vendor for replacement. Hope that takes care of it.

32 bit Ubuntu should detect > 4GB RAM at install and 'automagically' enable Physical Address Extensions, which lets you use up to 64GB RAM. Not in exactly the same way as 64 bit installs, but you can see it and use it. Check that your processor supports this first:

grep --color=always -i PAE /proc/cpuinfo

I had this same laptop (excellent machine, btw) with 4GB RAM and this all worked just fine.

Failing that, you can test your memory to make sure it is not the culprit here. You need to choose memtest86 at the GRUB menu. You can do this from the Live CD or USB if you have just one OS installed and don't usually see GRUB at boot.

If none of this helps, post an update to your question with more info and we can help you some more.

Refer to http://support.lenovo.com/en_US/product-and-parts/detail.page?DocID=PD008795

The note on MEMORY paragraph explains what chipsets only recognize 3GB even if the laptop has 4GB installed.

Then the OS needs to be 64bit in order to have the full 4GB available on the laptop whose chipset will support that memory size.


error in downloading graphics.h I am trying to download graphics.h header file but after

1.sudo apt-get install build-essential, there is no upgrade  in my pc

2.download of libgraph-1.0.2.tar.gz file.
3../configure it not working but, error is given as:

configure: error: *** SDL version 1.2.0 not found!

Please help?

How to fix it

For that error, you need to install development files for version 1.2 of libSDL and libSDL-image:

sudo apt-get install libsdl1.2-dev libsdl-image1.2-dev

It may also ask you for Guile, just install that one as well:

sudo apt-get install guile-1.8-dev

Then run ./configure again.

What was the problem

The software that you were trying to install, libgraph, has some dependencies. It uses other pieces of software and expects you to have them already installed. When you run ./configure, you check that you have everything you need before proceeding with the next step (make).

The error you got said that you don't have the headers for libSDL that are needed to compile libgraph. Of course, you can get the libSDL sources from the Internet and install them. But those have dependencies of their own, and it would be a rather tedious process. Instead, you can just install them from Ubuntu's repositories.

How to find out the required package name

apt-cache search libsdl | grep dev

For Ubuntu 17.10 and above

Follow the same steps as above except that you will need to install guile using

sudo apt-get install guile-2.0-dev

as guile-1.8 is no longer officially supported

Source: http://www.codingalpha.com/install-run-graphics-h-ubuntu/

Download Libgraph v(libgraph-1.0.2.tar.gz) to your USR directory in Linux Ubuntu.
Extract it in your USR Directory or the Home folder.
Now, you can do a #include and run your C programs


How to get to the GRUB menu at boot-time? My system is not dual-boot, I run a standard Ubuntu desktop system "on the metal" (I think running it in a VM is the same).

Pressing c while booting does not cause the GRUB menu to appear (which I believe it does for a dual-boot system).

How can I get the GRUB-menu to present itself on a single-boot system?

Menu will appear if you press and hold Shift during loading Grub, if you boot using BIOS. When your system boots using UEFI, press Esc.

For permanent change you'll need to edit your /etc/default/grub file -- place a "#" symbol at the start of line GRUB_HIDDEN_TIMEOUT=0.

Save changes and run sudo update-grub to apply changes.

Documentation: https://help.ubuntu.com/community/Grub2

For me, I found the issue was that I had left a USB stick plugged in to the computer. I suppose the computer was attempting to boot from the USB stick.
Once I had removed the USB stick, I could press shift or esc or space (depending on the version of Ubuntu you are using, I think).


apt-get count the number of updates available currently I use this to count the number of available updates

NUMOFUPDATES=$(aptitude search "~U" | wc -l)

Is there a way to do the same with apt(not aptitude) but not using the update-notifier?

You could use apt-check from update-notifier-common:

$ /usr/lib/update-notifier/apt-check --human-readable
0 packages can be updated.
0 updates are security updates.

This is the same tool that updates the motd message.

I just run the command:

sudo apt-get update && sudo apt-get upgrade

After performing the update process, it gives the output for upgrade command as:

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
  wine1.5 wine1.5-i386
2 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 24.1 MB of archives.
After this operation, 286 kB of additional disk space will be used.
Do you want to continue [Y/n]?

The 6th line mentions that there are 2 upgrades available and the 5th line lists the packages for which the upgrades are available. If I not in the mood to install the upgrades right at that moment I press n and move on.

Straight and simple.

Note: If there are kernal updates available as well, it would show them as <x> not upgraded.


Installing VLC 3.0.1 in Ubuntu 16.04 I am trying to install VLC in Ubuntu 16.04. By default, the version being provided from Ubuntu universe repositories is VLC version 2.2.2. But I checked the official website of VLC ( Videolan ), there I saw the latest version is 3.0.1.

I searched online on how to install latest VLC version, I got two solutions, either use a third-party PPA or use snaps. I searched for PPA, got ppa:videolan/stable-daily which installs version 2.2.2 and ppa:videolan/master-daily which installs version 4.0.0 rc1 (please correct me if I have gone wrong anywhere here).

So, finally, I resorted to snaps, installed VLC from it using sudo snap install vlc --classic. But the interface looked very weird to me, moreover, it downloaded 189 MB!

So is there any way to install the latest version using apt-get, the regular way?

There is no official release of latest VLC 3.0.2 for Ubuntu 16.04 LTS. However, you can get the latest VLC from the third party packager. To install VLC 3.0.2 in your system (Ubuntu 16.04 LTS) write the following commands in your terminal:

sudo add-apt-repository ppa:jonathonf/ffmpeg-3
sudo add-apt-repository ppa:jonathonf/vlc-3
sudo apt-get update
sudo apt-get install vlc

Now you are done! But, please note that according to the statement by the  packager, there is no Chromecast support for this particular package of VLC Media Player on Ubuntu 16.04 LTS. If you want that, then please upgrade to Ubuntu 18.04 LTS.

I had some trouble with installing some dependencies, which got resolved after I added this repository to the list that Blackcoat77 posted:

sudo add-apt-repository ppa:videolan/master-daily

I'm a noob, so please correct this with the stable release, if you think it also contains the dependencies. My understanding is that there is little to no quality control on this release, so use with caution.


Ubuntu 14.04 LTS, can not use apt-get -f install Anyone can help me please.

I just want to install letsencrypt, then i use the common command like sudo apt-get update && apt-get upgrade. But it return error to me, and it lets me try apt-get -f install.

I can not use apt-get -f install.

Thanks for your advice.

please try:

 `sudo rm /var/cache/apt/archive/lock`
 `sudo dpkg--cofigure -a`

I had same problem and they worked for me


Problem with terminal transparency I have a problem with the terminal on my Ubuntu netbook. Whenever I open the terminal it is completely transparent without a menubar or anything, and I can't see the text at all. Right clicking on it and messing around with the profiles doesn't do anything, and basically the only thing that the terminal shows is a silhouette. I know it's still there because if I click on the terminal and type in

unity -- reset

Unity appears to reset, and the terminal is again visible but I lose the ability to alt-tab and my taskbar is gone.

All help would be appreciated.

You can install Compiz Settings Manager. Open your terminal and execute:

sudo apt-get install compizconfig-settings-manager

After that open it and go to "Windows management" and check "Application switcher".

About missing taskbar - maybe is because you have disabled unity plugin. You can search for it in Compiz Config and enable it. You can try also this in the terminal:

 export DISPLAY=:0
 sudo dconf reset -f /org/compiz/
 setsid unity

If this does not work you can reinstall unity:

sudo apt-get -f install && sudo apt-get --reinstall install unity


High CPU usage when watching youtube videos (HTML5)? When I watch a youtube video, especially in HD, the browser I'm using (chrome) will use in excess of 200% of the CPU. This causes the video to stutter and also makes my laptop very hot. Is it normal for it to use this much CPU? Also, it's even worse when I watch it fullscreen.

I'm on a Dell Studio XPS1645 with a first generation i7 and a ATI radeonHD 4670 graphics card (With the latest proprietary drivers). Running Ubuntu 12.04 (but the same thing happens with earlier versions). Also I'm using the HTML5 version of youtube as flash performs even worse..

Can anyone help me resolve this issue or at least tell me if this is normal?

Thanks

This is something I had to deal with as well and I came to the conclusion if I use a desktop application like Miro, Totem, VLC, or MiniTube it makes my system run much better and cooler.

I prefer Miro, but it still needs some more development until it is perfect and crash free.  I hear MiniTube is great, but it is a paid app.  Totem works, but isn't as convenient.

I know this might not be your preferred method, but using Miro has opened up a lot of great content I wouldn't have found otherwise like free and creative commons audio books, music, and video series/episodes.

Also if you go this route check out Fluendo Codec. It improves video quality and works with Gstreamer. Only costs about $30 bucks.

Try Mozilla Nightly Browser!
Nightly browser will help you to reduce load on CPU. I may say that Nightly isn't stable as much as Firefox, but worth trying. Open terminal (Ctrl + T) and enter the following commands to install Nightly Browser.

sudo add-apt-repository ppa:ubuntu-mozilla-daily/ppa
sudo apt-get update
sudo apt-get install firefox-trunk


Has anyone successfully installed CUDA 7.5 on Ubuntu 14.04.3 LTS x86_64? My workstation has two GPUs (Quadro K5200 and Quadro K2200) with the latest NVIDIA Driver installed (Version: 352.41). After downloaded the file cuda-repo-ubuntu1404-7-5-local_7.5-18_amd64.deb from CUDA 7.5 Downloads, I try to install it, but it turns out the result as below:

root@P700-Bruce:/home/bruce/Downloads# sudo apt-get install cuda
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 cuda : Depends: cuda-7-5 (= 7.5-18) but it is not going to be installed
 unity-control-center : Depends: libcheese-gtk23 (>= 3.4.0) but it is not going to be installed
                        Depends: libcheese7 (>= 3.0.1) but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

I have tried the solution:

sudo apt-get remove nvidia-cuda-*  # remove old nvidia-cuda packages
Install unmet dependencies:

root@P700-Bruce:/home/bruce/Downloads# apt-get install cuda-7-5
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 cuda-7-5 : Depends: cuda-toolkit-7-5 (= 7.5-18) but it is not going to be installed
            Depends: cuda-runtime-7-5 (= 7.5-18) but it is not going to be installed
 unity-control-center : Depends: libcheese-gtk23 (>= 3.4.0) but it is not going to be installed
                        Depends: libcheese7 (>= 3.0.1) but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

root@P700-Bruce:/home/bruce/Downloads# apt-get install cuda-toolkit-7-5
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 cuda-toolkit-7-5 : Depends: cuda-core-7-5 (= 7.5-18) but it is not going to be installed
                    Depends: cuda-command-line-tools-7-5 (= 7.5-18) but it is not going to be installed
                    Depends: cuda-samples-7-5 (= 7.5-18) but it is not going to be installed
                    Depends: cuda-documentation-7-5 (= 7.5-18) but it is not going to be installed
                    Depends: cuda-visual-tools-7-5 (= 7.5-18) but it is not going to be installed
 unity-control-center : Depends: libcheese-gtk23 (>= 3.4.0) but it is not going to be installed
                        Depends: libcheese7 (>= 3.0.1) but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

Install and use aptitude

My Ubuntu14.04 OS is just installed and have made the software updates and installed the latest Nvidia driver.

Can you give some help? Thanks in advance!

The installation of CUDA is little a bit tricky. I've followed the following steps and it works for me. You can refer to this link also.

Confirmation of the environment:

lspci | grep -i nvidia
(Confirm that the information of NVIDIA's board is displayed)
uname -m
(make sure that it is a x86_64)
gcc --version
(make sure it is installed)

Installation of CUDA –

Download cuda_7.5.18_linux.run file from https://developer.nvidia.com/cuda-downloads
Run the following commands:

sudo apt-get install build-essential
echo blacklist nouveau option nouveau modeset=0 |sudo tee -a /etc/modprobe.d/blacklist-nouveau.conf
sudo update-initramfs -u

Reboot computer
At login screen, press Ctrl+Alt+F1and login to your user.
Go to the directory where you have the CUDA driver, and run

chmod a+x .
sudo service lightdm stop
sudo bash cuda-7.5.18_linux.run --no-opengl-libs

During installation:

Accept EULA conditions
Say YES to installing the NVIDIA driver
Say YES to installing CUDA Toolkit + Driver
Say YES to installing CUDA Samples
Say NO rebuilding any Xserver configurations with Nvidia

Check if /dev/nvidia* files exist. If they don't, do the following

sudo modprobe nvidia

Set Environment path variables

export PATH=/usr/local/cuda-7.5/bin:$PATH
export LD_LIBRARY_PATH=/usr/local/cuda-7.5/lib64:$LD_LIBRARY_PATH

Verify the driver version

cat /proc/driver/nvidia/version`

Check CUDA driver version

nvcc –V

Switch the lightdm back on again

sudo service lightdm start

Ctrl+Alt+F7 and login to the system through GUI
Create CUDA Samples, Go to NVIDIA_CUDA-7.5_Samples folder through terminal, then run following command:

make
cd bin/x86_64/linux/release/
./deviceQuery
./bandwidthTest

Both tests should ultimately output a 'PASS' in terminal
Reboot the system

-problems with lightdm log in ( login loop )

-problems with driver istall ( "Driver Installation failed: it appears, that a X server is running..." )

To successfully install a NVidia CUDA Toolkit on Ubuntu 16.04 64bit I've just had to do:

make a liveImage of Ubuntu on pendrive ( 8GB pen is enough ) -
such a try will save a ton of nerves, before unsuccessful
install on your host Linux system!!!
login on live session on pendrive ( "Try Ubuntu, before install"
)
add sudo user at live session:

sudo adduser admin  ( #pass: admin1 )

sudo usermod -aG sudo admin
logout from live session, log in as #admin
download CUDA Toolkit from NVidia official site ( ~1.5GB )
change privileges for downloaded installer file ( DO NOT INSTALL
AT THIS STEP! ):
sudo chmod +x cuda_X.X.run
switch to console view:

Ctr+Alt+F1 ( to switch on terminal view )
Ctr+Alt+F7 ( to switch from terminal view to graphical server )
at console view ( Ctr+Alt+F1 ) log in:

login: admin
pass: admin1
stop graphical running service:

sudo service lightdm stop
check if graphical server is off - after switching Ctr+Alt+F7
 the monitor should be blank black, switch back on console view
 Ctr+Alt+F1
install CUDA Toolkit, with such configuration:

sudo ./cuda_X.X.run
( press 'q' for license read skip )
do not install OpenGL library
do not update system X configuration
other options make yes and paths as default
turn on graphical server:

sudo service lightdm start
log in as user ( if you automatically log in as #ubuntu at live
 session log out ):

login: admin
pass: admin1
check whatever nvcc compiler works with provided simple
 parallel vector sum at GPU Blocks:

save vecSum.cu and book.h at new files, compile and run at terminal:
/usr/local/cuda-8.0/bin/nvcc vecSum.cu && clear && ./a.out
check console printout - it should be similar to:
0.000000 + 0.000000 = 0.000000

-1.100000 + 0.630000 = -0.000000

-2.200000 + 2.520000 = 0.319985

-3.300000 + 5.670000 = 2.119756
-4.400000 + 10.080000 = 5.679756
-5.500000 + 15.750000 = 10.250000
-6.600000 + 22.680000 = 16.017500
-7.700000 + 30.870001 = 23.170002
-8.800000 + 40.320000 = 31.519997
-9.900000 + 51.029999 = 41.129967

if everything went well on pendrive live session, do the same
on your host linux system

P.S. Please note that it is not ideal tutorial, but works fine for me!

======= vecSum.cu  =====

#include "book.h"
#define N 50000
///usr/local/cuda-8.0/bin/nvcc vecSum.cu && clear && ./a.out

//"HOST" = CPU
//"Device" = GPU

__global__ void add( float *a, float *b, float *c )
{
    int tid = blockIdx.x;
    if ( tid < N )
        c[ tid ] = a[ tid ] + b[ tid ];
}

int main ( void )
{
    float a[ N ], b[ N ], c[ N ];
    float *dev_a, *dev_b, *dev_c;
    //GPU memory allocation
    HANDLE_ERROR( cudaMalloc( ( void** )&dev_a, N * sizeof( float ) ) );
    HANDLE_ERROR( cudaMalloc( ( void** )&dev_b, N * sizeof( float ) ) );
    HANDLE_ERROR( cudaMalloc( ( void** )&dev_c, N * sizeof( float ) ) );

    //sample input vectors CPU generation
    for ( int i = 0; i < N; i++ )
    {
        a[ i ] = -i * 1.1;
        b[ i ] = i * i * 0.63;
    }

    //copy/load from CPU to GPU data vectors a[], b[] HostToDevice
    HANDLE_ERROR( cudaMemcpy( dev_a, a, N * sizeof( float ), cudaMemcpyHostToDevice ) );
    HANDLE_ERROR( cudaMemcpy( dev_b, b, N * sizeof( float ), cudaMemcpyHostToDevice ) );

    //calculate sum of vectors on GPU
    add<<<N,1>>> ( dev_a, dev_b, dev_c );

    //copy/load result vector from GPU to CPU c[] DeviceToHost
    HANDLE_ERROR( cudaMemcpy( c, dev_c, N * sizeof( float ), cudaMemcpyDeviceToHost ) );

    //printout results
    for ( int i = 0; i < 10; i++ ) printf( "%f + %f = %f\n", a[ i ], b[ i ], c[ i ] );

    //free memory and constructed objects on GPU
    cudaFree( dev_a );
    cudaFree( dev_b );
    cudaFree( dev_c );

    return 0;
}

========= book.h  ======

/*
 * Copyright 1993-2010 NVIDIA Corporation.  All rights reserved.
 *
 * NVIDIA Corporation and its licensors retain all intellectual property and
 * proprietary rights in and to this software and related documentation.
 * Any use, reproduction, disclosure, or distribution of this software
 * and related documentation without an express license agreement from
 * NVIDIA Corporation is strictly prohibited.
 *
 * Please refer to the applicable NVIDIA end user license agreement (EULA)
 * associated with this source code for terms and conditions that govern
 * your use of this NVIDIA software.
 *
 */

#ifndef __BOOK_H__
#define __BOOK_H__
#include <stdio.h>

static void HandleError( cudaError_t err,
                         const char *file,
                         int line ) {
    if (err != cudaSuccess) {
        printf( "%s in %s at line %d\n", cudaGetErrorString( err ),
                file, line );
        exit( EXIT_FAILURE );
    }
}
#define HANDLE_ERROR( err ) (HandleError( err, __FILE__, __LINE__ ))

#define HANDLE_NULL( a ) {if (a == NULL) { \
                            printf( "Host memory failed in %s at line %d\n", \
                                    __FILE__, __LINE__ ); \
                            exit( EXIT_FAILURE );}}

template< typename T >
void swap( T& a, T& b ) {
    T t = a;
    a = b;
    b = t;
}

void* big_random_block( int size ) {
    unsigned char *data = (unsigned char*)malloc( size );
    HANDLE_NULL( data );
    for (int i=0; i<size; i++)
        data[i] = rand();

    return data;
}

int* big_random_block_int( int size ) {
    int *data = (int*)malloc( size * sizeof(int) );
    HANDLE_NULL( data );
    for (int i=0; i<size; i++)
        data[i] = rand();

    return data;
}

// a place for common kernels - starts here

__device__ unsigned char value( float n1, float n2, int hue ) {
    if (hue > 360)      hue -= 360;
    else if (hue < 0)   hue += 360;

    if (hue < 60)
        return (unsigned char)(255 * (n1 + (n2-n1)*hue/60));
    if (hue < 180)
        return (unsigned char)(255 * n2);
    if (hue < 240)
        return (unsigned char)(255 * (n1 + (n2-n1)*(240-hue)/60));
    return (unsigned char)(255 * n1);
}

__global__ void float_to_color( unsigned char *optr,
                              const float *outSrc ) {
    // map from threadIdx/BlockIdx to pixel position
    int x = threadIdx.x + blockIdx.x * blockDim.x;
    int y = threadIdx.y + blockIdx.y * blockDim.y;
    int offset = x + y * blockDim.x * gridDim.x;

    float l = outSrc[offset];
    float s = 1;
    int h = (180 + (int)(360.0f * outSrc[offset])) % 360;
    float m1, m2;

    if (l <= 0.5f)
        m2 = l * (1 + s);
    else
        m2 = l + s - l * s;
    m1 = 2 * l - m2;

    optr[offset*4 + 0] = value( m1, m2, h+120 );
    optr[offset*4 + 1] = value( m1, m2, h );
    optr[offset*4 + 2] = value( m1, m2, h -120 );
    optr[offset*4 + 3] = 255;
}

__global__ void float_to_color( uchar4 *optr,
                              const float *outSrc ) {
    // map from threadIdx/BlockIdx to pixel position
    int x = threadIdx.x + blockIdx.x * blockDim.x;
    int y = threadIdx.y + blockIdx.y * blockDim.y;
    int offset = x + y * blockDim.x * gridDim.x;

    float l = outSrc[offset];
    float s = 1;
    int h = (180 + (int)(360.0f * outSrc[offset])) % 360;
    float m1, m2;

    if (l <= 0.5f)
        m2 = l * (1 + s);
    else
        m2 = l + s - l * s;
    m1 = 2 * l - m2;

    optr[offset].x = value( m1, m2, h+120 );
    optr[offset].y = value( m1, m2, h );
    optr[offset].z = value( m1, m2, h -120 );
    optr[offset].w = 255;
}

#if _WIN32
    //Windows threads.
    #include <windows.h>

    typedef HANDLE CUTThread;
    typedef unsigned (WINAPI *CUT_THREADROUTINE)(void *);

    #define CUT_THREADPROC unsigned WINAPI
    #define  CUT_THREADEND return 0

#else
    //POSIX threads.
    #include <pthread.h>

    typedef pthread_t CUTThread;
    typedef void *(*CUT_THREADROUTINE)(void *);

    #define CUT_THREADPROC void
    #define  CUT_THREADEND
#endif

//Create thread.
CUTThread start_thread( CUT_THREADROUTINE, void *data );

//Wait for thread to finish.
void end_thread( CUTThread thread );

//Destroy thread.
void destroy_thread( CUTThread thread );

//Wait for multiple threads.
void wait_for_threads( const CUTThread *threads, int num );

#if _WIN32
    //Create thread
    CUTThread start_thread(CUT_THREADROUTINE func, void *data){
        return CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)func, data, 0, NULL);
    }

    //Wait for thread to finish
    void end_thread(CUTThread thread){
        WaitForSingleObject(thread, INFINITE);
        CloseHandle(thread);
    }

    //Destroy thread
    void destroy_thread( CUTThread thread ){
        TerminateThread(thread, 0);
        CloseHandle(thread);
    }

    //Wait for multiple threads
    void wait_for_threads(const CUTThread * threads, int num){
        WaitForMultipleObjects(num, threads, true, INFINITE);

        for(int i = 0; i < num; i++)
            CloseHandle(threads[i]);
    }

#else
    //Create thread
    CUTThread start_thread(CUT_THREADROUTINE func, void * data){
        pthread_t thread;
        pthread_create(&thread, NULL, func, data);
        return thread;
    }

    //Wait for thread to finish
    void end_thread(CUTThread thread){
        pthread_join(thread, NULL);
    }

    //Destroy thread
    void destroy_thread( CUTThread thread ){
        pthread_cancel(thread);
    }

    //Wait for multiple threads
    void wait_for_threads(const CUTThread * threads, int num){
        for(int i = 0; i < num; i++)
            end_thread( threads[i] );
    }

#endif

#endif  // __BOOK_H__


Persistance with a remastersys ISO on a USB pendrive I'm trying to create a bootable ISO of Ubuntu 11.04 using remastersys's backup option.

Ubuntu's Make Startup Disk utility allows me to create a bootable USB drive with this ISO, but the option for using part of the USB drive to store documents/settings is grayed out.

Not surprisingly, creating the bootable USB drive in this way does not offer persistance (files/settings changes not preserved between reboots).

Does anyone know how I can create a bootable USB drive using this ISO with persistance?

You need a larger usb drive. At some point along the line, Ubuntu started requiring the persistent drive be a minimum of 1gb. If your distro leaves less than 1gb of free space on the usb drive you are using, it will be grayed out.

I got the same, but I noticed that was because I had deleted all the partitions.
In the Startup Disk Creator, if the size option is gray, select the USB key and click on Erase. It will create a partition and the disk space size slider will be enabled.


How to fix "sudo: unable to open ... Read-only file system"? The title might not be as descriptive as I would like it to be but couldn't come up with a better one.

My server's file system went into Read-only. And I don't understand why it does so and how to solve it.

I can SSH into the server and when trying to start apache2 for example I get the following :

username@srv1:~$ sudo service apache2 start
[sudo] password for username:
sudo: unable to open /var/lib/sudo/username/1: Read-only file system
 * Starting web server apache2                                                                                (30)Read-only file system: apache2: could not open error log file /var/log/apache2/error.log.
Unable to open logs
Action 'start' failed.
The Apache error log may have more information.

When I try restarting the server I get :

username@srv1:~$ sudo shutdown -r now
[sudo] password for username:
sudo: unable to open /var/lib/sudo/username/1: Read-only file system

Once I restart it manually it just start up without any warning or message saying something is wrong.

I hope somebody could point me into the right direction to resolve this issue.

The filesystem will usually go into read-only while the system is running if there is a filesystem consistency issue. This is specified in fstab as errors=remount-ro and will occur when a FS access fails or an emergency read-only remount is requested via Alt+SysRq+U. You can run:

sudo fsck -Af -M

to force a check of all filesystems. As one of the other answers states, looking at dmesg is also very helpful.

Edit: Don't forget the -M on the command-line.

NOTE: As mentioned by Bibhas in his answer: If fsck gets stuck after its version banner:

$ sudo fsck -Af -M
fsck from util-linux 2.20.1

you may want to try using the EXT4-specific fsck

$ sudo fsck.ext4 -f /dev/sda1

Provided the partition in question /dev/sda1 was an ext4 filesystem.

It's misconfigured boot settings (try mounting / as ext2) not drive or partition physical error.

dmesg | grep "error" gave me:

ext3-fs (sda2): error: couldn't mount because of unsupported optional features (240)
ext2-fs (sda1): error: couldn't mount because of unsupported optional features (240)
ext4-fs (sda2): mounted file system with ordered data mode: opts: (null)

It mounted / as read only due to the fstab error=mount-ro directive.


Dell Unified Linux Driver installer I'm trying to set up a dell B1160w printer and am having trouble.

I'm using the A00 Unified Linux driver which I can get running but then is says SANE - scanner api is needed.  I have SANE 1.0.23 installed.

When I do "instal anyway" if seems like the printer is installed but it does nothing when I try to print anything (meaning it goes to the print queue, looks like it's about the print the just goes to idle and nothing happens)

Anyone had this problem or have any ides on how to fix it?

I had exactly the same problem as described by nhadfield on 8/21/13.   First I looked into
the answer about Ghostscript, but it was already installed.

I had followed the instructions at How do I install the drivers for my Samsung printer?, which
led me to install
B1160_B1160w_UnifiedLinuxDriver_1.01.tar.gz

However, today I discovered also B1160w_Linux_v1.04_Driver.tar.gz
at
http://www.dell.com/support/drivers/us/en/555/driverdetails?driverid=M4HVD

I downloaded this 1.04 version and then installed it as follows using the
Terminal.   It seems to be working.

cd
cd Downloads
gunzip B1160w_Linux_v1.04_Driver.tar.gz
tar -xvf B1160w_Linux_v1.04_Driver.tar
cd cdroot
cd Linux/
sudo ./install.sh

Try http://www.ghostscript.com/. Install and configure then try and run the installer again.


Adobe Flash for Ubuntu 14.04 LTS not working I know there are a lot of questions about this, I have tried many of them. I still cannot utilize Adobe on my Chromium. I have updated and reinstalled and still nothing. I am fairly new to Ubuntu and Linux and would appreciate any help on the subject. Please no more links to similar questions since they seem to be more specific to other issues than the one I am having. Thanks in advance.

Pepper Flash is Chrome/Chromium only (made by Google), not Firefox. If you want to uninstall it, you can do

sudo apt-get remove pepperflashplugin-nonfree

but really, there is no reason to as it can coexist with the Adobe version of Flash.

To install flash, do

sudo apt-get install flashplugin-nonfree

If that doesn't work, we will need more details as far as what exactly is going wrong.

Source: https://wiki.debian.org/PepperFlashPlayer

Adobe has a tiny remark on their site:

Note: Ubuntu Linux requires libhal (Hardware Abstraction Layer). Install hal to play the protected content.

This brought me to http://www.omgubuntu.co.uk/2013/10/fixing-amazon-prime-streaming-drm-protected-flash-13-10.
By following the instructions at the bottom of the page I installed libhal and my Flash problems with Chrome in Ubuntu14.10 are over.

-edit- Disregard, after a while Flash crashed again....., sorry.


why am i not getting my ubuntu 12.10 login screen back after uninstalling xubuntu 12.10? I installed xubuntu, then uninstalled it completely, but I am not getting my original log-in screen back. It's a simple log-in screen with the computer's icon, user name, password and session details in front of the default 12.10 background in a small log in window in the center. I want the original log in screen. (dotted wallpaper with changing background as you change the user)

Do I have to install Ubuntu again to get the log-in screen back?

You need to open a terminal and then copy / paste the following:

sudo dpkg-reconfigure lightdm unity-greeter

and select lightdm as your display manager if prompted.

Also run the following to remove the greeter you don't want:

sudo apt-get remove lightdm-gtk-greeter

Updated:
Now run

gksu gedit /etc/lightdm/lightdm.conf

and make sure the file looks like this:

Please let me know if this works for you or not.

Try sudo apt-get --purge -remove xubuntu-


Windows-like global shortcuts with the  key in Xubuntu I would to define Windows-like shortcuts using the Super ("Windows") key. I'm running Xubuntu 11.04 (Natty).

Using Settings->Settings Manager->Windows Manager->Keyboard I assigned Super+D to "Show desktop".

Then, using Settings->Settings Manager->Keyboard->Applications Shortcut I assigned Super+E to thunar. So far, everything works perfectly.

But, at least, I'd like the Super key when pressed alone to open the Applications Menu but, being Super a modifier key I wasn't able to assign it alone to a shortcut. For reference this problem is also described here.

Based on this forum post I used to xmodmap to make it behave like a normal key - ie. not a modifier key. And guess what, it works. Sorta.

Super alone works perfectly. Super+E still opens thunar but also opens the Applications Menu. Super+D no longers works at all.

Of course, I can just remove my .Xmodmap file and assign a Super+A or similar to Applications Menu. But if there's a way to get just Super working it would be great.

Can someone shed some light on this issue?

I had the same issue and I finally resolved it. Since there is no way to solve this with Xfce alone, one needs the small tool ksuperkey. It was originally developed for KDE, but it works fine on other desktops. You basically install ksuperkey or compile it yourself, and bind your menu to "alt+f1". Once you run ksuperkey, the superkey will behave as one would expect. I highly recommend to put this tool into some form of autostart, so that ksuperkey gets started on startup. Set it and forget it!

Restore back what you did. In natty super key is already used for menu.


Ubuntu mobaxterm that has drag and drop I am using my pc to connect to the server with GPUs and need to do a lot of transfers. I used mobaxterm when on Windows. It has drag and drop which is very convenient. Is there a similar tool on ubuntu?

A list of Linux alternatives to Mobaxterm is found at https://alternativeto.net/software/mobaxterm/?platform=linux but you will need to think about what features are essential vs important vs nice to have, then sift through what you find there. I'd also suggest you scratch off the list any which are discontinued, or no longer supported.

You can use Termius for SSH but this is not Look like a Mobaxterm.
But it's Providing many Features like Authentication Key, you can Create Group of Host, SFTP, Key Store Etc.


Change password on root user and user account If I change the password for the root user is that going to automatically change the password for the user account?

I found this link for root:

WikiHow: How to Change the Root Password in Linux

How do I change the user account password?

To do it using command line:

To change the root password:

sudo passwd

To change your user password:

passwd

To change other users password:

sudo passwd USERNAME

To do it GUI open the application User Accounts from the Dash and there you can change password easily for all users unless the root

As a user, you can change your own password in a terminal, using passwd. You will be asked for the current password and can then enter a new one.

On Ubuntu, there normally is no separate password for root. Instead, users with administrator privileges may use sudo to run commands as a super user.


Updating man-db to patch CVE-2015-1336 / CVE-2017-9525 Am running Ubuntu 16.04.5 LTS.

The default man-db packaged on Ubuntu 16.04 has a vulnerability (CVE-2015-1336 & CVE-2017-9525).

ii  man-db        2.7.5-1         amd64        on-line manual pager

  The daily mandb cleanup job in Man-db before 2.7.6.1-1 as packaged in Ubuntu and Debian allows local users with access to the man account to gain privileges via vectors involving insecure chown use.

apt-get update/upgrade won't update to a version that doesn't have this vulnerability.  How can I instruct Ubuntu to upgrade to a newer package?

Thanks for your help.

I ended up doing this:

sudo wget http://mirrors.kernel.org/ubuntu/pool/main/m/man-db/man-db_2.7.6.1-2_amd64.deb
sudo dpkg -i man-db_2.7.6.1-2_amd64.deb

Seemed to work.


How can I improve Ubuntu overall system performance? What are your tips for improving overall system performance on ubuntu? Inspired by this question I realized that some default settings may be rather conservative on Ubuntu and that it's possible to tweak it with little or no risk if you wish to make it faster.

This is not meant to be application specific (e.g. make firefox load pages faster), but system wide.

Preferably 1 tip per answer, with enough detail for people to implement it.

A couple of mine would be:

Install Preload (via Software Center or sudo apt-get install preload);
Change Swappiness value - "which controls the degree to which the kernel prefers to swap when it tries to free memory";

What are yours?

PS: Since this is not intended to have a unique answer but rather, several useful tips, I'm making this community wiki out-of-the-box.

If you are "the average Joe", then just don't do anything. Don't fiddle with programs or settings which you don't understand. Don't follow tips posted on the Internet how to improve the performance of your system by compiling some software yourself or by installing a selfmade kernel.

Some of those tips may give you minor performance improvements indeed, but some of them will also give you a real headache, if you changed the wrong setting, disabled the wrong service, installed the wrong driver etc.

Therefore just be happy about your nicely running system. And BTW: Why would you need those 5 percent performance improvements? It will not lead to typing your office documents faster or editing your holiday photos in half the time.

And just to be clear: If you are not the average Joe, but a developer/hardcore gamer/... needing any cycle you can get, you are not the target of this comment...

Using localhost as the the host name

This method could improve the speed of start the application .

nano /etc/hosts

127.0.0.1          localhost Ubuntu
127.0.1.1          Ubuntu

In the end of the first line, add the host name, which is the name of the second line.


Installing ubuntu to a specific disk drive alongside Windows 7 on separate disk I have deleted an entire disk drive (120 GB ssd) for ubuntu to be installed on.  However, when I install ubuntu 13.04 from DVD, it never prompts me as to which disk drive to install on.

Unfortunately, something is failing at the very end, so I have no idea where ubuntu is trying to install, but I'd at least like to make sure it is installing to the completely unallocated disk drive.

When you get the options on where to install Ubuntu you can chose between installing it alongside Windows, erasing the disk or something else.

Installing it alongside Windows will shrink your Windows partition and create a new one. If you already created one, that isn't detected. So what you want to chose is something else.

Just follow the official instructions on this.

If you already picked the first option you might now have ended up with a Windows partition that is too small to boot. You can fix this by booting the Live-CD/USB to the desktop ("just try Ubuntu, don't install"). Now run gparted to view all your harddrives and partitions. Delete the Ubuntu partitions and resize the Windows partition to the maximum. While you're at it, you can also use gparted to easily create the partitions you need on your second drive (chose it in the top right) and then just select them in the Ubuntu installer.

When manually installing Ubuntu on a second harddrive (/dev/sdb) you probably want the bootloader GRUB to be on the first harddrive (/dev/sda) so make sure your selection looks sound.

I used to installing ubuntu in a separate drive using the installation process guide.  It is simple, easy if you follow the steps well, also I advice to install the grub on the same drive to prevent problems with my windows drive beside if you decide or accedently format your ubuntu drive you still have your. Windows drive untouched.


Photo manager that organises by folder structure I have my pictures very well organized on the harddisk, in this structure:

Pictures

Canon

Holiday 2010

Sony

Graduation 2000

Other Albums

Steves Holiday 2010 Album

Thus, I have a main folder that holds all my pictures, and within a lot of folders with subfolders of at least 2 levels (device & album name).

I used Picasa to organize my pictures on Windows, now on Ubuntu I would like to use a more native application than running Picasa on Wine.
There is a lot of applications out there, but none of these seems to be able to import all my pictures and organize it in the hierarchy I arranged them in with folders and subfolder like Picasa does it.

Is there an application, preferably for the GNOME desktop that can do this?

digiKam (Click to Install)

  digiKam is an image organizer and editor using KDE Platform. It runs on most known desktop environments and window managers if needed libraries are installed. It supports all major image file formats, and can organize collections of photographs in directory-based albums, or dynamic albums by date, timeline, or by tags. Users can also add captions and ratings to their images, search through them and save searches for later use.

If you are using GNOME here's how to make digiKam look native .

Shotwell (Included in default)

  Shotwell can import photos and videos from a digital camera directly. Shotwell automatically groups photos and videos by date, and supports tagging. Its image editing features allow users to rotate, crop, eliminate red eye, and adjust levels and color balance. It also features an auto "enhance" option that will attempt to guess appropriate levels for the image. Shotwell allows users to publish their images and videos to Facebook, Flickr, Picasa Web Albums, Piwigo, and YouTube.


No HDMI sound on ubuntu 13.10 I have my computer connected to my Sony TV, the HDMI video output works fine but I cant get the audio to work. I can see the HDMI output option in the sound settings but nothing happens. When I plug in my headphones the sound works fine

Do you guys have any solution to this ?

You can try to run

pactl set-card-profile 0 output:hdmi-stereo

This should set the audio output to HDMI.

Open a terminal using CTRL+ALT+T and type in the following command:

sudo alsa force-reload

It works on 13.10 (for me, atleast.)


How to completely reset Ubuntu and all installed applications to its original setting? I have been using Ubuntu 14.04 LTS for some time now. I need to reset it to original state without reinstalling my Ubuntu. Is it possible??

Try below command that would reconfigure everything you have this will not do any harm to your system.

sudo dpkg-reconfigure -a


Change DocumentRoot in 16.04 I've read quite a few posts on how to change apache2 DocumentRoot on Ubuntu 16.04.

Here's what I did:

Edit /etc/apache2/apache2.conf to show:

<Directory /media/werner/EDrive/www/html>
    Options Indexes FollowSymLinks
    AllowOverride None
    Require all granted
</Directory>

Edit /etc/apache2/sites-available/000-default.conf to show:

DocumentRoot /media/werner/EDrive/www/html

<Directory "/media/werner/EDrive/www/html">
    AllowOverride All
</Directory>

Edit /etc/apache2/sites-available/default-ssl.conf to show:

DocumentRoot /media/werner/EDrive/www/html

Restart apache2.

sudo service apache2 restart

Now if I go to localhost, I get a 403 Forbidden error.
Permissions of /media/werner/EDrive/www/html:

drwxr-xr-x 30 www-data www-data 4096 Nov 29 13:09 html/

What to do? In my mind, I am pointing at the right directory, but there seems to be a permissions issue!? My user (werner) is a member of the www-data group.

I found the issue. The ROOT of my new directory (i.e /media in my case) must be owned by www-data

So

sudo chown -R www-data:www-data /media

did the trick for me


Brightness is reset to maximum on every restart The brightness of my laptop is reset to max on every restart. I tried the solution provided at this website but had no luck.

This command

cat /sys/class/backlight/acpi_video0/max_brightness

Returns

cat: /sys/class/backlight/acpi_video0/max_brightness: No such file or directory

Then I found that I don't have a folder named acpi_video0, but a folder called intel_backlight:

Every time I increase or decrease the brightness using the brightness control keys, the values in brightness and actual_brightness get updated.

Is there any method I could follow to set the brightness to a fixed value on every boot and vary it as and when I need it using the brightness control keys?

You could try adding a line to /etc/rc.local that will set the desired brightness level. To edit the file, run

sudo -H gedit /etc/rc.local

and add the following

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

so that the end result looks like this

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

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

exit 0

Substitute X by the desired brightness level.

In case /etc/rc.local doesn't exist, as is the case with new Ubuntu releases, you'll need to create it, and make eecutable with the following commands:

printf '%s\n' '#!/bin/bash' 'exit 0' | sudo tee -a /etc/rc.local
sudo chmod +x /etc/rc.local

PS: Alternatively, there may be /sys/class/backlight/acpi_video0/brightness instead of the above. Brightness levels vary wildly, and may range from 0 to 10 or to 1000. To find the maximum value, try

cat /sys/class/backlight/acpi_video0/max_brightness
or
cat /sys/class/backlight/intel_backlight/max_brightness

It is well worth checking the max_brightness files for the absolute maximum values in /sys/class/backlight/intel_backlight and /sys/class/backlight/acpi_video0 directories to avoid setting unusable values.

My Dell Inspiron 5720 uses maximum values of 4882 and 100 respectively.  I have set these to 2508 and 52 to prolong battery life. ACPI value in this case is equivalent to the percentage of the maximum brightness.

Editing rc.local works for me. I added comments to clarify how the values were determined. set required brightness with function keys and read values in brightness or actual_brightness files in each of the above Intel / ACPI directories.


Can I mount an ISO without administrative privileges? Can I mount an ISO in Ubuntu 10.04 without requiring the use of sudo?

This is all I know how to do:

sudo mount -o loop -t iso9660 image.iso /media/iso

A few answers mentioned using something called "Archive Mounter". I've never noticed this before, but I do see it listed in the "Open With" list when right-clicking ISO files.

Where can I find documentation on how to use it?

To mount an ISO without administrator privileges you can use fuseiso:

fuseiso image.iso ~/mountdir

Unmount the image using fusermount:

fusermount -u ~/mountdir

If you don't have fuseiso you will have to install it from the repositories:

sudo apt-get install fuseiso

You will need administrator privileges to install.

The functionality you ask for should be perfectly covered by pmount (man page).  In your case, the following command:

pmount -o loop -t iso9660 image.iso iso

should mount your image.iso under /media/iso

EDIT: this doesn't work, as pmount has no "-o" option


How do I start/stop mysql server? I tried to find in some articles describing how to correctly start & stop mysql server.

I found this link: How to start/stop MySql server on Ubuntu 8.04 | Abhi's Blogging World

I ran this command:

/etc/init.d/mysql start

but I see this error

ERROR 1045 (28000) Access denied for user....

After I tried this command:

sudo /etc/init.d/mysql start

I entered my password, and again I see the same error.

Next command:

sudo /etc/init.d/mysql - root -p start

results in:

ERROR 1049 (42000) Unknown database 'start'.

And when I run this command:

sudo service mysql start

MySQL server success started. Cool!

So, what's wrong with the other commands? Why do they result in error?

Your first two commands weren't run as root so that is expected behaviour. You need to be root to stop/start mysql.
However:
sudo /etc/init.d/mysql start

should work. Indeed it does, for me:
kojan:~> sudo /etc/init.d/mysql restart
[sudo] password for chris:
Stopping MySQL database server: mysqld.
Starting MySQL database server: mysqld.
Checking for corrupt, not cleanly closed and upgrade needing tables..

I used restart rather than start, since it was already running, but the effect is the same. Are you sure you entered your password correctly? :) Have you edited your sudo config at all which would stop this working?
This one..
sudo /etc/init.d/mysql - root -p start

The arguments are wrong. an init.d script only takes start or stop or restart - just one word telling it what to do. You cannot give it multiple arguments as you were trying to do.
Anyway, the short answer is the one you actually got to work, is the recommended way. service is replacing all the init.d scripts over time, so you should get into the habit of using service. The page you link to was written in 2008, so has to be taken with some salt :)

A little script to cover both cases [server running/server not running]:

#!/bin/bash

service mysql restart
if [ "$?" != "0" ]; then
  service mysql start
fi


My mouse automatically changes themes My mouse is set to a theme named DMZ-White i.e. the default theme in Ubuntu but ever since I installed and uninstalled deepin de my mouse becomes white only when it's on unity-greeter or firefox or some of the other apps. The other mouse theme that I don't want cannot be found in /usr/share/icons/ but it has a black pointer and the watch icon is a black wrist watch
Can someone please tell me whats going on and how can I solve it.

Note: I have tried changing mouse themes but the they work the same as DMZ-White does i.e. only in some places and in the rest the same unknown theme appears

Log into the guest session and type the following commands: (assuming user is your old user name)

su - user
sudo adduser user2

and follow the instructions on-screen.  If you're not on a US keyboard, don't use any "special" characters like £ à ŷ ü nor any numbers unless they're from your keypad.

Now type the following commands:

sudo adduser user2 adm
sudo adduser user2 cdrom
sudo adduser user2 sudo
sudo adduser user2 dip
sudo adduser user2 plugdev
sudo adduser user2 lpadmin
sudo adduser user2 sambashare

(If any of the above gives an error like group not found, don't worry: I'm trying to be thorough)

Now, log out of the guest session and log in as "user2" and come back here to this site.

Ah you're back!  ;-)  Please test now if you still have your problem...  No?  OK!

Now,

open the file manager
browse to the /home/user directory
copy (don't move!) all the files from Downloads to /home/user2/Downloads
check you did a good job.
Now delete /home/user/Downloads
Go back to step 3 and repeat for Documents, Videos, ...
In a terminal type the following command: deluser user --remove-home

Done!


Java: Could not find or load main class I developed a small Java program under windows and am now trying to run it on an ubuntu machine.

run.sh:

/opt/atlassian/jira/jre/bin/java -classpath "commons-lang3-3.3.2.jar;opencsv-3.3.jar;.\TisowareExportConverter.class" info.aptis.plakon.TisowareExportConverter /home/tisoware/transfer/tisoware_presence_export.csv /home/tisoware/convert/$

I compiled the .java file under windows

Directory contents

tisoware@server037:~/convert$ ls -la
insgesamt 472

    drwxr-xr-x 2 root         root           4096 Apr 26 11:51 .
    drwxr-xr-x 7 tisoware     tisoware       4096 Apr 26 11:32 ..
    -rw-r--r-- 1 root         root         412739 Apr 18 15:46 commons-lang3-3.3.2.jar
    -rw-r--r-- 1 root         root            293 Apr 26 11:51 convert.sh
    -rw-r--r-- 1 root         root           1024 Apr 26 11:51 .convert.sh.swp
    -rw-r--r-- 1 root         root            108 Apr 26 10:47 doku.txt
    -rw-r--r-- 1 root         root          31217 Apr 18 15:46 opencsv-3.3.jar
    -rw-rw-r-- 1 root         tisoware          5 Apr 26 11:24 outfile.csv
    -rw-r--r-- 1 aptisSupport aptisSupport    200 Apr 19 14:19 tiso_user_mapping.csv
    -rw-r--r-- 1 root         root           4425 Apr 19 14:21 TisowareExportConverter.class

The java class

package info.aptis.plakon;

public class TisowareExportConverter {

    public static void main (String[] args) { /* stuff is done here */}
}

Problem

All I get is

tisoware@server037:~/convert$ bash convert.sh
Fehler: Hauptklasse info.aptis.plakon.TisowareExportConverter konnte nicht gefunden oder geladen werden

(Translation: Could not find or load main class info.aptis.plakon.TisowareExportConverter)

What am I doing wrong?

Under Windows the program runs like this

run.bat

java -classpath libs\commons-lang3-3.3.2.jar;libs\opencsv-3.3.jar;out\production\tisowareExportConverter2 info.aptis.plakon.TisowareExportConverter tiso_infile.csv tiso_outfile.csv tiso_user_mapping.csv

Thank you, Internet <3

While executing, when JVM does not find a .class file with the specified name then a run time error occurs saying “Could not found or load main class”. The reason why this happens is mostly due to:

Wrong Class Name
Invalid Classpath
Wrong package

Main class could not be found when there is typo or wrong syntax in the fully qualified java class name or it does not exist in the provided classpath. You must ensure that you add the location of your .class file to your classpath. So, if its in the current folder, add . to your classpath. Note that the Windows classpath separator is a semi-colon( . If you want to execute the main() method in MainClass, you must use the full class name, including package name, in the java command.

I worked around this problem by packaging the class as a jar like this:

https://stackoverflow.com/questions/2025607/how-to-create-a-jar-file-or-export-jar-on-intellij-like-eclipse-java-archive-e


How to navigate long commands faster? Is there a way speed up Linux CLI  navigation when I must enter long commands?
I simply use arrows right now, and  - if I have a long command it takes some time to get from start of the command to the middle of it.

Is there a way to for example jump to the middle of the command without using arrows?

Some useful line editing key bindings provided by the Readline library:

Ctrl + A: go to the beginning of line
Ctrl + E: go to the end of line
Alt + B: skip one word backward
Alt + F: skip one word forward
Ctrl + U: delete to the beginning of line
Ctrl + K: delete to the end of line
Alt + D: delete to the end of word

Source the code-snippet below in your .bashrc. Ctrl-a jumps to the start and pressing Ctrl-a again jumps to the middle.

jump_mid() {
    if [ "$READLINE_POINT" -eq "0" ]; then
        LEN=${#READLINE_LINE}
        POS=$(($LEN / 2))
        READLINE_POINT=$POS
    else
        READLINE_POINT=0
    fi
}
bind -x '"\C-a" : jump_mid'

Or if you want to use Ctrl-Something to directly jump to the middle, change the code to:

jump_mid() {
    LEN=${#READLINE_LINE}
    POS=$(($LEN / 2))
    READLINE_POINT=$POS
}

And bind it to something different than Ctrl-a.


I am not able to find other people on my local network when playing Counter Strike 1.6 I have Ubuntu 16.04 and the others have Windows. I am not able to see their server nor are they able to see my servers. I am also not able to find any internet servers.

I am using wine to run Counter Strike 1.6

However, I am able to connect directly to the host ip and join the game. This is why it's not similar to this question

Does anyone know how to solve this issue? Has anyone faced this issue?

try this command :

sudo iptables -R INPUT 5 -p udp -m udp --sport 26900:27030 --dport 1025:65355 -j ACCEPT

also you can read  :
https://www.linode.com/docs/game-servers/launch-a-counter-strike-global-offensive-server-on-ubuntu-14-04


Ubuntu 12.04 - Trouble with UFI Boot on Macbook Pro Retina (late 2013) I used the following tutorial to set up Ubuntu 12.04 as dual boot on the Macbook Pro Retina (late 2013):

I did followed this article

It sets up Ubuntu as dual boot with EFI Boot only (without Grub). However, I have some issues with the boot configuration... According to the tutorial, the boot manager (ReFind) needs a kernel on the HD of Mac OS X to be able to find it, so I copied the kernel files from Ubuntu to MacOS X in /EFI/ubuntu and provided the information to the boot manager as described in the tutorial.

However, in my case, ReFind can boot the kernel but it fails to boot at the end since it cannot find the folder /dev/disk/by-uuid and boots into the initramfs shell. Creating the folder manually and providing a syslink with the UUID as name, linking to the correct partition (in my case ../../sda4) lets me boot Ubuntu.

Only Problem is that I have to do those settings each time I reboot. As soon as Ubuntu is loaded, the /etc/disk/by-uuid folder exists as well as the /etc/fstab (which does not exist when booted into initramfs). But when I reboot I can only get to the initramfs shell again and have to create the folder and syslink again.

So not really sure what is happening there. Does anybody have idea?

It seems like the /dev/disk/ I get access to from the initramfs shell is not the one of the actual Ubuntu. Is this possible?

You need to boot in to OSX and install rEFInd in OSX, Macs dont reconize any version of linux by default, so your need to install it on your OSX partition. After that you reboot your mac and rEFInd should pop up


Terminal Closes Immediately on Open 14.04 I tried to follow other answers on here that I found but I cannot stop my terminal from closing as soon as it opens on Ubuntu 14.04 LTS.

Here are my profile files.

.bashrc
.profile
/etc/bash.bashrc
/etc/profile

Environment is simply

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games

Thanks for your help.

Seems to only happen after adding my user to the sftp user group. My other account worked fine until I did this.

Your problem is that, by the time you open a terminal, the i flag is no longer set in '$-'. Replace:

# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac

with:

# If not running interactively, remember
case $- in
    *i*) IsInteractive=1;;
      *) IsInteractive=0;;
esac


One Ubuntu 16.04 system finds the package libsqlite3-dev, but another does not I do the following on one Ubuntu machine (Ubuntu 16.04.3 LTS)

sudo apt-get install libsqlite3-dev

it shows

E: Unable to locate package libsqlite3-dev

But if I perform the same command on the other one (Ubuntu 16.04.3 LTS too), it shows the following and the package is installed successfully

After this operation, 1,699 kB of additional disk space will be used.
Get:1 http://sg.archive.ubuntu.com/ubuntu xenial/main amd64 libsqlite3-dev amd64 3.11.0-1ubuntu1 [508 kB]
Fetched 508 kB in 1s (383 kB/s)
Selecting previously unselected package libsqlite3-dev:amd64.

I suspect the repository:

http://sg.archive.ubuntu.com/ubuntu xenial/main amd64

is not in the first machine repository list. How should I add it?

Some mirrors may be out of sync.

Try to select other mirror:

open Software & Updates (software-properties-gtk)
on Ubuntu Software tab select other server (for example Main Server) from Download from drop-down menu.
if you planning to compile something check Source code

confirm reloading lists

Then try to install you program again with:

sudo apt-get install libsqlite3-dev

First, try updating your sources:

    sudo apt-get update

Check for any error messages here, and try installing again.

If you still have errors, you can check your active repositories with the following command:

    sudo nano /etc/apt/sources.list

The line you are looking for should be the first active source in this file. The format should read:

    deb http://sg.archive.ubuntu.com/ubuntu/ xenial main restricted

Inactive sources will have "#" at the beginning of the line. Remove this to activate them. Additionally, you can add your own sources at the end of this file.

After editing your sources file, you will want to update apt again:

    sudo apt-get update


How to change from Legacy boot to UEFI boot? SO, I have been trying to get ubuntu linux on my windows 8 pre-installed VAIO laptop. The USB stick containing the ubuntu boot wasn't working right, so I went into the BIOS and changed UEFI boot to legacy. Now when I turn on my computer with the USB, it displays, "SYSLINUX 4.04 EDD 2011-04-18 COPYRIGHT (C) 1994-2011 H. PETER ANVIL et al". Without the USB, it just says that there is no operating system, and Windows 8 doesn't boot. I am worried that I broke my computer. Can anyone tell me how to change back to UEFI so that Windows 8 will boot, or even how to get the Linux Ubuntu USB to boot right? Thanks.
1 second ago - 4 days left to answer.

Take the hard drive out of your laptop.  This should allow you to get into the UEFI.  If that does not work, the instructions (take from the VAIO User Guide) to get into the UEFI are as follows:

Press the ASSIST button while your VAIO computer is off.
The VAIO Care Rescue Mode screen appears.
Select Start BIOS setup.
Enter a password if it has already been set.
The BIOS setup screen appears.

Now, you should be able to change back to UEFI from Legacy boot.  As far as the second part of your question, this should help you in doing what you need to do.  To make this answer more complete, I will add that guide here:

If you want Ubuntu on the same disk as Windows 8.1, here are the steps to go through:

1) Turn off Windows Fast Boot

2) You need to shrink the main Windows 8.1 partition.  This can be tricky, as Windows expects a certain partition scheme to be used.  Let me show you a diagram:

[(Windows RE Tools)(EFI System Partition)(Microsoft Reserved Partition)(Windows 8.1)(Anything else)]

You can use your favorite tool to edit these partitions.  I prefer Gparted, but any good disk partitioning tool can handle this.  Backup your Windows install first.  Then, resize the Windows 8.1 partition so that you have enough space for another OS.  I prefer to give my Linux installs about 50-100 GB of space (for expandability).

3)  Download your Ubuntu (use 64 bit only and I suggest 13.10) iso and put it on some media (CD/DVD/USB/(insert your preferred media here)) by using your favorite tool (most people prefer Rufus) or dd.

4) Shut off Secure Boot and Fast Boot in the UEFI.  DO NOT TURN ON LEGACY BOOTING (if your motherboard supports UEFI only booting without Secure Boot and Fast Boot on.)

5) Insert your install media and install Ubuntu in the partition you made earlier.  Make sure that for your EFI boot partition, you make the installer use the EFI System Partition already created by Windows 8.1.  The partition should be something like sdXn (replace X with the drive it is on and n with the partition number, such as /dev/sda2), but this could be different.  DO NOT REFORMAT THIS PARTITION!!  You are only going to tell the installer to use it as the EFI partition.  It will put the grubx64.efi bootloader for Ubuntu in this location.

6) With that done, continue the install as normal and set up your partitions as you see fit.  Once the install is finished, you should be able to boot into Jessie easily.

If you are trying to fix an existing install of Ubuntu, you will need to do:

sudo apt-get install grub-efi-amd64

sudo modprobe efivars

sudo grub-install /dev/sdx (x being the drive Ubuntu is installed on)

sudo update-grub

From there, the UEFI should use Grub-EFI as the bootloader. I have not found a way to get the Windows 8 bootloader to see and allow Linux to boot in UEFI.  YYMV.

Just hold the Assist button and keep pressing F2.


Ubuntu Netboot - PXE can't find kernel 'linux' I just set up my PXE Server on Lubuntu, everything is running good so far.. PXE detects my DHCP Server, menu shows up, but when I select one of the entrys, for example the one that leads to ubuntu-installer, it shows the errormessage 'loading /ubuntu-installer/amd64/linux failed no such file or directory' I've tried nearly everything from moving 'linux' into another folder to chmod 777 my tftp root folder. Does anyone know how to handle this?

Just download the linux file inside the ubuntu-installer (link)  and replace the bad linux file ( tftpboot/bionic64/ubuntu-installer/amd64.

http://archive.ubuntu.com/ubuntu/dists/bionic/main/installer-amd64/current/images/netboot/ubuntu-installer/amd64/

That work for me !


Upgrade from 12.04 to 12.10 loops and fails with "Unable to get exclusive lock" I'm trying to upgrade from 12.04 to 12.10 but it consistently fails in the same way.

First, the upgrade process loops (do-release-upgrade) by going through the following many times

Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Building data structures... Done

Then it dies with "Unable to get exclusive lock".

I am not running another package manager, so this is not a duplicate of Unable to use package manager due to "exclusive lock" error.

Anybody has any ideas how to go about fixing this? I tried looking at the logs in /var/log/dist-upgrade but I couldn't find any useful error information.

I would check around, because I believe at one time you could change the repository name from say precise to quantal to produce the same effect. The process was ensure that you updated everything in your current version with repo's and then switch them and run sudo apt-get dist-upgrade.

Dropbox and Citrix ICA clients blocked my attempts at removing dpkg and apt processes.  I removed those two apps, THEN killed dpkg and apt processes, and the good ol'apt-get worked fine without the lock problem.


Install netgear WNA1000m on Ubuntu Server 12.04 LTS I have been looking all day on the internet for a solution to installing the Netgear WNA1000m Wifi USB dongle on my Linux Ubuntu Server 12.04 LTS.

I found some interesting articles on this forum as well on others and I've been gone through some steps succesfully to identify the USB dongle.

What I did:

lsusb

and after this:

modinfo 8192cu | grep 9041

The last command gave me an error which said that the module could not be found.

I hope you guys can help me out on installing this wifi dongle.

I'm actually very new to Ubuntu, but I'm willing to learn a lot of the Linux OS and I hope you guys can tell me why and how you did some steps, even if they might be basic.

Thanks already!

You can correct my English if I said something incorrect, because it's not my native language

I found this link to be of great help.

How to install driver for RTL8188CUS Wireless adaptor?

It discusses the pitfalls of going about it on your own with third party software and provides you with what worked for my problem which is just a slightly different version then what you printed.


How do I delete everything in /var/mail/username from the command line? As a result of a long-running cron job, I have over 1,000 messages in my user's mailbox. What's the easiest way to delete them?

If you want to delete all the messages, you can simply truncate the mailbox file for a user with the following command:

> /var/mail/username

(the greater than sign is not a prompt: you are in effect redirecting the output of nothing to the file, which will truncate it).

It depends if you have ftp access. If so, just use Nautilus to do a good deal more than any other ftp client. I also use it and Bluefish to edit pages on my websites.

There should be a Mail folder where you can view and  delete any and all files.

I find it so much easier than File Manager in cPanel.


IcedTea-8 cannot run any jnlp application (maybe due to openjdk-11?) I'm on Ubuntu MATE 18.04. All the jnlp applications I tried give execution error. After inspection, some libraries seem to be missing in Java.

So I removed everything, started installation again, and found that apt-get install icedtea-8-plugin depends on:

  ca-certificates-java default-jre default-jre-headless icedtea-8-plugin
  icedtea-netx librhino-java libtagsoup-java openjdk-11-jre
  openjdk-11-jre-headless

While it is expected to depend on openjdk-8, not 11 (according to ubuntu packages website). I suspect that jdk-11 does not include some libraries required for this.

My guess is that I installed some PPA that now produces this situation where jdk-11 is a more up to date choice than any jdk-8 package. So, how can I achieve that icedtea-8 is installed with openjdk-8, and not 11?

EDIT:
This is the output when I try to launch from firefox a jnlp application:

Denying permission: ("java.lang.RuntimePermission" "accessClassInPackage.sun.util.resources")
net.sourceforge.jnlp.LaunchException: Fatal: Launch Error: Could not launch JNLP file. The application has not been initialized, for more information execute javaws/browser from the command line and send a bug report.     at net.sourceforge.jnlp.Launcher.launchApplication(Launcher.java:582)
...
Running jdk9+ ?
java.lang.ClassNotFoundException: sun/misc/JarIndex
...
java.io.FileNotFoundException: /home/roman/.config/icedtea-web/deployment.properties (No existe el archivo o el directorio)     at java.base/java.io.FileInputStream.open0(Native Method)

The ClassNotFoundException: sun/misc/JarIndex is what made me thought that is due to the dependency on jdk11, since this class seems to have been removed in Java 9.

I tried installing only openjdk-8, and then build icedtea from source. Nevertheless, when I finished, it was not detected by firefox (maybe some command was missing).

Any idea?

Also, find below the output of those commands (after trying installing according to your answer):

roman@roman-desktop:~$ update-java-alternatives -l
java-1.11.0-openjdk-amd64      1111       /usr/lib/jvm/java-1.11.0-openjdk-amd64
java-1.8.0-openjdk-amd64       1081       /usr/lib/jvm/java-1.8.0-openjdk-amd64
roman@roman-desktop:~$ which javaws
/usr/bin/javaws

After some trial and error I found only one useful solution - we need to install normal OpenJDK 8 from previous Ubuntu 16.04 LTS manually with commands below. It is usually not recommended, but we do not have other methods with positive result.
So the commands to install are the following (we remove existing OpenJDK and then install deb-packages manually):
sudo apt purge oracle-java11-* -y
sudo apt purge *openjdk* -y
sudo apt autoremove --purge -y

wget http://archive.ubuntu.com/ubuntu/pool/main/o/openjdk-8/openjdk-8-jre-headless_8u272-b10-0ubuntu1~16.04_amd64.deb
sudo apt install -y ./openjdk-8-jre-headless_8u222-b10-1ubuntu1~16.04.1_amd64.deb

wget http://security.ubuntu.com/ubuntu/pool/main/libp/libpng/libpng12-0_1.2.54-1ubuntu1.1_amd64.deb
sudo apt install -y ./libpng12-0_1.2.54-1ubuntu1.1_amd64.deb

wget http://archive.ubuntu.com/ubuntu/pool/main/o/openjdk-8/openjdk-8-jre_8u272-b10-0ubuntu1~16.04_amd64.deb
sudo apt install -y ./openjdk-8-jre_8u222-b10-1ubuntu1~16.04.1_amd64.deb

wget http://archive.ubuntu.com/ubuntu/pool/universe/i/icedtea-web/icedtea-netx-common_1.6.2-3ubuntu1_all.deb
sudo apt install -y ./icedtea-netx-common_1.6.2-3ubuntu1_all.deb

wget http://archive.ubuntu.com/ubuntu/pool/universe/i/icedtea-web/icedtea-netx_1.6.2-3ubuntu1_amd64.deb
sudo apt install -y ./icedtea-netx_1.6.2-3ubuntu1_amd64.deb

Also we need to pin/hold the versions of such packages with single long command below:
cat <<EOF | sudo tee /etc/apt/preferences.d/pin-java8
Package: icedtea-netx
Pin: version 1.6.2-3ubuntu1
Pin-Priority: 1337

Package: icedtea-netx-common
Pin: version 1.6.2-3ubuntu1
Pin-Priority: 1337

Package: openjdk-8-jre
Pin: version 8u272-b10-0ubuntu1~16.04
Pin-Priority: 1337

Package: openjdk-8-jre-headless
Pin: version 8u272-b10-0ubuntu1~16.04
Pin-Priority: 1337

EOF

and then the application will run with
javaws StartProRealTime.jnlp

Notes: the installation of Oracle Java 11 or 12 does not help either.

https://openwebstart.com/
I am not much of a geek but since previous answers are very old I am posting new answer
OpenJDK 8/11 didn't work for me, I have found the above link in GitHub for the same issue. I was able to open Jnlp files from lab live using openwebstart.
Note : My answer is related only to lab live Jnlp files and this is the first time I am using JNLP files
Thanks


How to stop umount all when I exit ssh session? So when i'm logged into Lucid via ssh, and type exit to end the session, umount -a is run first by the system. I see the follow message before it logs me out:

umount: /home: device is busy.
    (In some cases useful info about processes that use
     the device is found by lsof(8) or fuser(1))

umount: /var/run: device is busy.
    (In some cases useful info about processes that use
     the device is found by lsof(8) or fuser(1))

umount: /dev/shm: device is busy.
    (In some cases useful info about processes that use
     the device is found by lsof(8) or fuser(1))

umount: /dev: device is busy.
    (In some cases useful info about processes that use
     the device is found by lsof(8) or fuser(1))

umount: /: device is busy.
    (In some cases useful info about processes that use
     the device is found by lsof(8) or fuser(1))

How can i stop this?

however, seems that it doesn't unmount the folders at all..

well let's do a read to ``man on_exit man page, maybe some configuration on the machine you are log in is playing with you.


What does the name after '@' at terminal prompt mean? I noticed that when in terminal the prompt is generally in the format username@users: or I have even seen username@(none):. I get that the first part is the logged in person's user name, but what is the part after the @ symbol?

It's the hostname, i.e. the name that you gave your computer.

Showing this as part of the prompt is useful so you can easily tell which host a given shell is running on if you're logged into multiple computers (via ssh or telnet for example).

Just use command groups to list all groups that your current user is part of. Root user is an administrator account on Windows language which you might better understand.


Deleting empty lines in LibreOffice Calc In Libre office calc I have a bunch of cells that contain empty lines. A single cell looks like this:

How can I delete the empty lines from the cells to get cells that look like this:

I do not want to edit 200 cells by hand to delete the blank lines. I'm sure there is a faster way.

P.S. I obtained these cells by copying a table from a website into Libre office calc. For that I used the clip-board.

I assume you want to remove multiple empty lines in one step if possible. To remove a single line, there's a context menu entry.

There are two possible approaches to remove multiple lines without much hassle:

as proposed in this answer: sort the lines alphabetically so the empty lines get sorted to the start or end, then delete them.
as proposed in this blog post: use filtering to get only the blank lines displayed, then select and delete them, then remove the filter.

EDIT:

To remove hard line breaks inside cells automatically, you could use the search / replace functionality and regular expressions. Just search for \n and let the replace box empty. Don't forget to activate "Regular expressions" under More Options.... You won't see a result immediately, since Calc doesn't change the row height automatically. So you will have to set the row height using Optimal row height... in the context menu after removing the line breaks.

EDIT 2:

It may be possible that there aren't any empty lines in the cells, so the search/replace operation may fail. This is because LibreOffice automatically applies styles from the original html tables when pasting data from the web. To make sure that it isn't just a row format issue, just select the complete sheet and select Optimal height... from Menu Format -> Row.

Download LO Calc guide here and go to page 32!


Xrandr won't correct screen orientation I changed from Debian 9 to Ubuntu 17.10 today. I was on facebook when suddenly my screen turned upside down. That has already happened sometimes when I used Debian, so I just tried the usual command

  xrandr -o normal

However, it didn't work. I started looking at the internet and tried other solutions, such as

  xrandr --output  --rotate normal

It also didn't work. I can't rotate left, right or upside down either. My computer is an HP Elitebook 8440p and I am using only the notebook screen, no other monitors connected. When I logged off from my user, the screen was in the correct orientation, but logging in back turned it upside down again. How can I solve it?

Obs.: Restarting the machine worked, but do I need to do it everytime?

My computer is also a hp, in my case the orientation sensor is under the keyboard rather than the screen so UBUNTU and GNOME make things difficult.

To return the screen to normal incline the computer, pretend that the screen is the keyboard and the keyboard the screen; in that orientation the screen will return to normal. Now go to the top right menu and check for the 3 buttons in the bottom, the middle one is to lock the screen rotation, click it and the screen will no longer change orientation.


How i can fix network adapter issue on ubuntu 20.04? im unable to connect either by wifi or lan to internet
how i can fix this my wifi is product : Wi-Fi 6 AX201
LAN product : Realtek Semiconductor

I recommend to use Kernel 5.7.4 or higher for using the Intel AX200, older kernel versions don't seem to work well but with that version this network card works decently well, at least on Ubuntu 20.04.
sudo su
cd /tmp/

wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.8.3/amd64/linux-headers-5.8.3-050803-generic_5.8.3-050803.202008211236_amd64.deb
wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.8.3/amd64/linux-headers-5.8.3-050803_5.8.3-050803.202008211236_all.deb
wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.8.3/amd64/linux-image-unsigned-5.8.3-050803-generic_5.8.3-050803.202008211236_amd64.deb
wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.8.3/amd64/linux-modules-5.8.3-050803-generic_5.8.3-050803.202008211236_amd64.deb
dpkg -i *.deb
Uninstall Linux Kernel 5.8:
Restart your machine and select boot with the previous kernel in boot menu ‘Grub2 -> Advanced Option for Ubuntu’. Then run command to remove Linux Kernel 5.8:
sudo dpkg --purge linux-image-unsigned-5.8.3-050803-generic_5.8.3-050803.202008211236_amd64.deb
or
sudo apt purge linux-image-unsigned-5.8.3-050803-generic_5.8.3-050803.202008211236_amd64.deb