Install Ubuntu from ISO... cannot install grub

I needed to modify grub configuration to boot from an iso image from HD since BIOS changing to USB boot was password locked, so a linux live was not viable.

I managed to boot from iso by typing what was needed in the grub editor at boot time.

So, technically, I solved my problem without answering this question, and I still do not know the answer.

But installation failed anyway.
I then got a password for the BIOS, change boot to USB, used a linux live and installed 16.04 with no problem.

Conclusion: the results of an installation attempt from iso on HD was different than from USB, even if they should be the same (failure vs. success).


unable to install applications from software centre. Installation failing

Now We try method 2

We are try remove & reinstall Software center.

To remove Software Center:

1. sudo apt-get remove software-center

sudo apt-get autoremove software-center

To re-install Software Center:

sudo apt-get update
sudo apt-get install software-center

or you can use single command for remove & reinstall Software Center

sudo apt-get --purge --reinstall install software-center

Now this will work & after this method work vote up the answer.
Best of luck.


Alias not working as intended in .bashrc, while command does

The question's syntax highlighting should show you where you went wrong: the alias starts with a double quote, and then you use another double quote, closing the original, so the command substitution (and "${aux}" later on) is evaluated when the alias is created, not when it is run. So if you run alias readlast, it would look like:

alias readlast="aux=<name-of-file>; cat "

The "${aux}" is of course empty, because it wasn't set at the time the alias was created. That's why cat is waiting for input - without a filename, it just echoes back standard input.

You could fix it by using single quotes for the entire alias definition (and removing the single quotes from within the alias):

alias readlast='aux="$(find /home/w/Dropbox/notes/ -type f -printf "%T@ %p\n" | sort -n | tail -1 | cut -f2- -d" ")"; cat "${aux}"'

Or use a function:

readlast()
{
    aux="$(find /home/w/Dropbox/notes/ -type f -printf '%T@ %p\n' |
      sort -n |
      tail -1 |
      cut -f2- -d" ")"
    cat "${aux}"
}

As a side note, you can simplify the pipe using sed:

readlast()
{
    aux="$(find /home/w/Dropbox/notes/ -type f -printf '%T@ %p\0' |
      sort -zrn |
      sed -z 's/[0-9.]* //; q')"
    cat "${aux}"
}

The \0 in -printf and -z for sort/sed is input delimited with the ASCII NUL character instead of newlines. It's the only character not valid in a path, so it's the safest for dealing with filenames and paths. With -r, sort will reverse the order for you, and the sed command then strips off the timestamp and quits after the first line of input.


By 2020, it's possible to do Screen Mirroring on a Samsung Smart TV as Wireless Display, without any HDMI cable (I use it every day, Samsung TV UN40J5500, with Ubuntu 20.04).
The simplest way to do it, in my opinion, is to install gnome-network-displays via flatpak.

Download .flatpakref from Flathub: https://flathub.org/apps/details/org.gnome.NetworkDisplays
Install: flatpak install org.gnome.NetworkDisplays.flatpakref
Run: flatpak run org.gnome.NetworkDisplays
Select TV to display

Should start streaming screen to TV.

Important: check that your audio is working on TV. In my case, I need to use PulseAudio Volume Manager.

Install: sudo apt install pavucontrol
Run: pavucontrol
Select: Output Devices -> Show: Virtual Output Devices -> Set Fallback.

Finally, if your TV is not located or if screen is suddently frozen, this is what I do:

close gnome-network-displays (if open)
stop: systemctl stop NetworkManager.service
stop: systemctl stop wpa_supplicant.service
start: systemctl start NetworkManager.service
start: systemctl start wpa_supplicant.service

Then, I re-open the network displays and it goes back to work.
My experience with Wireless Displays is usually very good, I manage to watch movies with audio in perfect sync. Just for extra information, I use 5GHz Wifi (maybe it helps...) on router Archer C60, and my CPU is Intel(R) Core(TM) i5-4210U CPU @ 1.70GHz (not very new but works fine).
For extra information, it's nice to visit the project repository: https://gitlab.gnome.org/GNOME/gnome-network-displays
Another project that "partially worked" for me was MiracleCast (at least for TV discovery and motivation to know if it COULD work possibly on linux...). I don't think it's complete yet (see Open Issue), but it's another possible alternative for the future: https://github.com/albfan/miraclecast/issues/4
Good luck!
https://gitlab.gnome.org/GNOME/gnome-network-displays


upgrade from 14.04 to 16.04 on digitalocean

This solve my issue:

sudo add-apt-repository -y -r ppa:chris-lea/node.js
sudo rm -f /etc/apt/sources.list.d/chris-lea-node_js-*.list

source


I think I found it. First post describes how ureadahead works. Will keep searching.

https://lwn.net/Articles/401561/
https://lwn.net/Articles/299483/


Intel® Wi-Fi 6 AX201 module causing Wi-Fi not detected errors upon fresh install, Ubuntu 18.04LTS

The Intel AX201 is a very new wifi module. It requires kernel version 5.2.x as a minimum. However currently, as of December 2019, Ubuntu 18.04 LTS is packaged with a 5.0.x kernel, and will not come with a kernel new enough to support it out of the box till sometime around February 2020. This is why you'll notice the network module being marked as unclaimed. That is to mean that there is no driver attached to it that can run the hardware. While Canonical strives to ensure that new hardware will always get support as soon as possible (these kernel updates are provided as part of the Hardware Enablement stack), computers with this wifi card will currently have to install a pre-release (a beta designed for developers to test their hardware) version of the kernel to gain wifi.

Install the new kernel this way:

sudo apt install linux-generic-hwe-18.04-edge

and you should be on your way. (the -edge denotes that this is the pre-release)

It is worth pointing out that there are many ways to install a kernel - one possibility is to install a kernel directly from the Linux mainline. However this is generally not recommended as this is only used to help test compatibility for future stable releases, and an optimized version for your distro can often be found instead to improve performance. What is best is to install a kernel update developed for your distro and version specifically.

Hope this helps someone in the future!


Bazaar - pull the last revision only (and not the whole branch)

To some degree, you can do this by running:

$ bzr branch --stacked REMOTE-URL LOCAL-PATH

this will create a local branch that only has the last few revisions. It is an independent branch, so if you do a commit in the local branch, it won't automatically get pushed into the remote branch. If you try to access any data in the local branch that is not available, bzr will shell out to the remote branch to find that data.


My friend installed Ubuntu and I can't uninstall it or get into the BIOS anymore

Your computer's UEFI or BIOS is stored on the motherboard, and is the first thing that the computer runs before it can even look for an operating system.  So nothing you do in regards to having (or not having) an operating system installed on your computer will affect that.  Every manufacturer triggers the UEFI/BIOS setting screen in a different way, though, so you'll need to check the manual for your motherboard for more information.  (Try searching the make and model number on Google.)

You don't really uninstall operating systems, you delete them.  If you are ever installing a new operating system and do not want the existing operating system and data on your computer, you just install the new operating system and tell the installer to use your entire disk.


Uninstall MySQL workbench 6.2 on ubuntu 14.04

So i had the same package not installed error and that was because i was targeting the wrong package.

https://dev.mysql.com/doc/workbench/en/wb-linux-uninstalling.html

as found in this link i tried sudo apt-get remove mysql-workbench-community and this worked for me.


Can't run write benchmark in Disks (gnome-disks) on Ubuntu MATE 16.04.1

Note: Tested on 14.04 and 16.04

This is normal. You can't unmount a filesystem that is in use. On top of that  the gnome-disks write benchmark is destructive and even warns you to backup before using it as shown below:

Due to this you only want to write benchmark disks that don't have important data on them as it will be overwritten. I always boot from live media to benchmark disks with gnome-disks

For a safer benchmarking method see my answer using fio to a similar question here.


As you can see from the following the git-all package certainly exists on 14.04 and does not require a PPA:

andrew@corinth:~$ apt-cache policy git-all
git-all:
  Installed: (none)
  Candidate: 1:1.9.1-1ubuntu0.3
  Version table:
     1:1.9.1-1ubuntu0.3 0
        500 http://au.archive.ubuntu.com/ubuntu/ trusty-updates/universe amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/universe amd64 Packages
     1:1.9.1-1 0
        500 http://au.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
andrew@corinth:~$

It is in the 'Universe' section of the Ubuntu Repositories so make sure you have this activated by following the trail:

Dash --> Software & Updates --> Ubuntu Software --> Community maintained....

See this screenshot where the mouse cursor indicates the appropriate Repository:

After activating 'Universe' and allowing the Repository index to reload, rid yourself of the PPA and then simply run:

sudo apt-get install git-all

And all should be well...


How do I list new drives so I can partition and format them?

Run parted interactively, then use the print devices command, like below:

sudo parted
GNU Parted 2.3
Using /dev/xvda1
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print devices
/dev/xvda1 (8590MB)
/dev/xvdb (429GB)


How is being able to break into any Linux machine through grub2 secure?

How is the ability of a person who gained physical access to your computer to get root [using Grub/Bash] in any way secure?

Because if Linux decided to start doing that, hackers would just exploit other security holes. The first rule of security is that if I have physical access to your system, it's game over. I've won.

Plus, imagine your X server broke and you don't have a GUI anymore. You need to boot into a recovery console to fix things, but you can't because that's insecure. In this case, you're left with a totally broken system but hey, at least it's "secure!"

  But Kaz, how is this possible? I set a password on my Grub so that you can't change my init to Bash!

Oh, you did, did you? Interesting, because this looks like your photo album. GRUB doesn't have any inherent security factor at all. It's just a bootloader, not a step in some secure boot and authentication chain. The "password" you've set up is, in fact, pretty darn easy to bypass.

That, and what sysadmin doesn't carry a boot drive on them for emergencies?

  But how?! You don't know my password (which is totally not P@ssw0rd btw)

Yeah, but that doesn't stop me from opening your computer and pulling out your hard drive. From there, it's a couple simple steps to mount your drive on my computer, giving me access to all of your system. This also has the awesome benefit of bypassing your BIOS password. That, or I could have just reset your CMOS. Either/or.

  So... how do I not let you get access to my data?

Simple. Keep your computer away from me. If I can touch it, access a keyboard, insert my own flash drives, or take it apart, I can win.

  So, can I just like put my computer in a datacenter or something? Those are pretty secure, right?

Yeah, they are. But, you're forgetting that humans are hackable too, and given enough time and preparation, I could probably get into that datacenter and siphon all of that sweet, sweet data off your computer. But I digress. We're dealing with real solutions here.

  Okay, so you called my bluff. I can't put it in a datacenter. Can I just encrypt my home folder or something?

Sure, you can! It's your computer! Will it help stop me? Not in the slightest. I can just replace something important, like /usr/bin/firefox with my own malicious program. Next time you open Firefox, all of your secret data is siphoned off to some secret server somewhere secret and you won't even know. Or, if I have frequent access to your machine, I can just set up your home folder to be copied to /usr/share/nonsecrets/home/ or any similar (non-encrypted) location.

  Okay, what about full disk encryption?

That's... actually pretty good. However, it's not perfect yet! I can always perform a Cold Boot Attack using my trusty can of compressed air. Or, I can just plug a hardware keylogger into your computer. One's obviously easier than the other, but the way doesn't really matter.

In the vast majority of cases, this is a good stopping place. Maybe pair it with TPM (discussed below), and you're golden. Unless you've angered a three-letter agency or a very motivated hacker, nobody's going to go through the effort required past this stage.

Of course, I can still get you to install some malware/backdoors by offering you a PPA or similar, but this gets into the very murky area of user trust.

  So... how are iPhones so secure? Even with physical access, there's not much you can do.

Well, yes and no. I mean, if I was motivated enough, I could read the flash chip and get everything I need. But, iPhones are fundamentally different inasmuch as they're a fully locked down platform from the very start of the bootup process. This, however, causes you to sacrifice usability and the ability to recover from catastrophic failures. GRUB  (except when very specifically designed) is not meant to be a chain in a security system. In fact, most Linux systems have their security chains start post-boot, so after GRUB has finished doing its thing.

iPhones additioanlly have cryptographic signature enforcement (also discussed below), which makes it very hard for malware to sneak on to your phone.

  But what about TPM/SmartCards/[insert crypto tech here]?

Well, now you're pairing physical security into the equation, it becomes more complicated still. But, this isn't really a solution because TPMs are relatively weak and all encryption doesn't take place on-chip. If your TPM is (somehow) strong enough where it does encryption on the chip itself (some very fancy hard drives have something like this), the key won't ever be revealed and things like cold-boot attacks are impossible. However, the keys (or the raw data) might still be present in the system bus meaning they can be intercepted.

Even so, my hardware keylogger can still get your password, and I can easily load some malware onto your machine a la the Firefox exploit I mentioned earlier. All I need is for you to leave your house/computer for maybe an hour.

Now, if you take your TPM/smartcard/whatever with you, and all the encryption is actually done on the chip (meaning your key isn't stored in RAM at all), then it's  practically impossible for me to get in at all. This assumes, of course, that there isn't any known security vulnerability I can exploit and that you follow good security practices.

  But what if I have some form of cryptographic/digital signature enforcement on all of my programs to make sure they're legit?

As demonstrated by various smartphone companies, this is a very good way of dealing with security. You've now nullified my ability to inject some code onto your machine to do nefarious things. Effectively, you've disabled my ability to retain persistent access to your machine remotely.

However, this still isn't a perfect method! Digital signature enforcement won't stop a hardware keylogger, for one. It also needs to be completely bug-free, meaning there's no way I can find an exploit that allows me to load my own certificate into your machine's certificate store. Furthermore, this means every executable on your system needs to be signed. Unless you want to manually go through and do all of that, it's going to be very hard to find Apt packages and the like that have digital signatures on everything. In a similar vein, this blocks legitimate uses for unsigned executables, namely recovery. What if you break something important, and you don't have the (signed) executable to fix it?

Either way, an effort to do this on Linux has basically been all but abandoned and no longer works for new kernels, so you'd need to create your own.

  So, it's impossible to keep you out of my computer?

Effectively, yes, sorry. If I have physical access and enough motivation, it is always possible to get into a system. No exceptions.

In reality, though, most evil people won't try to go this far just for some cat pictures. Typically, just full-disk encryption (or even just running Linux!) is enough to deter most script kiddies from having their two seconds of fame.

TL;DR: Just don't let people you don't trust near your computer and use LUKS. That's typically good enough.


Try inspecting the MAAS logs, I think something is wrong over there. Also, looks like you are not running the latest MAAS, and it also helps to run the latest juju:

sudo add-apt-repository ppa:juju/stable
  sudo add-apt-repository ppa:maas-maintainers/stable
  sudo apt-get update
  sudo apt-get dist-upgrade # (or selectively install juju-core and maas packages)


The problem turned out to be related to DNS look-ups.  My system couldn't display websites because it wasn't able to look up their IP information via my DNS servers.

This was solved by resetting /etc/resolv.conf to:

# Use Google DNS
nameserver 8.8.8.8
nameserver 8.8.4.4


Can't write to mounted ext4 hard drive in Ubuntu 18.04

The HDD mount made by the gnome-disk-manager should be ok
I guess you just have to fix perms on HDD :
Open a terminal CTRL+ALT+T and enter the command below

sudo chown $USER:$USER /mnt/stuff

If this does not the trick, go next:

The last line of /etc/fstab should be your HDD
You may edit this last line
Main change is in the mount options (defaults) and fsck option (2)

sudo nano /etc/fstab #(or sudo gedit /etc/fstab)
#
# Edit the last line
UUID=c0c74b6f-dedb-4a3e-b5d8-52cca8a0958e /mnt/stuff ext4 defaults        0       2

Save the file and change (take) ownership on HDD

# Remount the HDD
sudo umount -f /mnt/stuff
sudo mount -a
sudo chown $USER:$USER /mnt/stuff
# non recursive change of ownership should be enough, but
# if still cannot write on it, go for a (longer) recursive change of ownership
# sudo chown -R $USER:$USER /mnt/stuff
# -R is for recursive


Software location after installing via Ubuntu Software Center

How I installed subclipse
Changed /home/username/.eclipse/org.eclipse.platform_3.7.0_155965261/configuration/eclipse.ini.ignored
to /home/username/.eclipse/org.eclipse.platform_3.7.0_155965261/configuration/eclipse.ini just in case.

Installed subversion and the java wrapper
sudo apt-get install subversion libsvn-java
Check the version svn --version On 12.04 it's 1.6
I went to "Help->Install new software"

Added the matching site for svn integration.  Make it match the version of libsvn.

Installed the full load of packages

Restarted eclipse from the command line to check for errors
I don't get any

I pulled an SVN repo to verify it working...ffmpeg svn is still up btw


After a lot of searching for solutions, I also found myself in similar situation. AndrewM's solution did not work for me either. The Mac is on pure EFI (non-hybrid), pure 64 bit Linux.

A couple points to make: 1) There are two projects, rEFIt and rEFInd.  2) You can install both and I have found that they will detect each other and let you boot one from the other.

Here is what finally got me back into Linux after Mavericks upgrade... Download the latest rEFind http://www.rodsbooks.com/refind/ (currently 0.7.4) and issue this command from OS X:

sudo ./install.sh --alldrivers

I ended up with a long menu of all my Linux kernels and was able to boot directly into Ubuntu / Debian without GRUB menu.  Now at least I can get into Linux and rework the GRUB and look at EFI configurations.


Does deleting the interfaces config file reset ifconfig to default (DHCP)

AFAIK rebooting will not create a new default /etc/network/interfaces file. Assuming your default interface name is eth0 you should have her create or edit it manually as

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp

If you are not sure about the interface naming convention, have her run ifconfig or ls /sys/class/net to identify the correct name.


Ubuntu 20.04 Mail Setup Setting the Default From Address

This information should be located in /etc/postfix/main.cf. Open the file and look for two variables:
myhostname=server.myserveraddress.com
mydomain=myserveraddress.com

Note: If you do not have a mydomain variable, you can add it.
Restart Postfix and you should be good:
sudo systemctl restart postfix.service


Copy the .desktop file from /usr/share/applications (or just add it to desktop and then create a copy) so that you don't have to edit all from the start and then:

First option

Change the Exec= line to:

Exec=terminator -e "sudo -i"

This will ask for your password when you open terminator.
Second option

Install gksu (sudo apt-get install gksu) and change the Exec= line to:

Exec=gksu terminator

This will open a pop up which will ask you your password and give you a root terminator without any user preferences though.

NOTE: Never run sudo terminator because it might change the user folder ownership or cause other problems, always use gksu for gui applications.


Have you had a look at stipple and oneconf?

They seem to take care of the basics. For anything not covered there, you may want to use rsync or unison (both can work over ssh; unison actually uses rsync for the trasfer, iirc).


ubuntu build kernel from git with a source change, how to ignore 'unrepresentable changes to source' error

Ah, my local changes were a red-herring.
somehow a python script got added in part of the source tree, some kind of debugging assistant.

To fix:
1 Following instructions here to remove all non-tracked files from the working tree

https://koukia.ca/how-to-remove-local-untracked-files-from-the-current-git-branch-
571c6ce9b6b1

I did

To remove ignored and non-ignored files, run git clean -f -x or git clean -fx

Return to the instructions here:
https://wiki.ubuntu.com/KernelTeam/GitKernelBuild

at step 4, copy the config in.

Then it builds.

these are my complete notes. Some of these steps are unnecessary but they don't hurt. Obviously, ignore the cherry-pick.

fakeroot debian/rules clean
cp /boot/config-`uname -r` .config
yes '' | make oldconfig
make clean
#remove the non git files
git clean -f
rm vmlinux-gdb.py
#make sure there is no linux*.tar too
rm ../linux*.gz

#cherry pick RC6 hack
git cherry-pick 0c6b6fa52c6ad54332eed64acb6aebc59f75e0b2

#
make -j `getconf _NPROCESSORS_ONLN` deb-pkg LOCALVERSION=-custom
cd ..


Ubuntu 14.04 how to install cuda 6.5 without installing nvidia driver

Install aptitude

sudo apt-get install aptitude

and then run

aptitude

Click on Search type nvidia, use the arrow keys to go to nvidia-340.46 and click on Package and then Hold.

(and then still take a full system backup before installing CUDA; I use CloneZilla as a system backup: just take the / partition and leave the /home partition out!  Works like a charm!)

Also, now you have aptitude, so even if things go wrong, you can still log into the console (Ctrl+Alt+F1) and use aptitude to delete whatever CUDA installed....


In a standard Ubuntu desktop install, DNS is managed by a DNSMasq instance started by Network Manager. I've certainly witnessed NM crash a few times when coming back from suspend and exhibit things like you describe.

I fix them by running:

sudo service network-manager restart

Depending on how often you're doing this, it might be worth digging in and working out why it's crashing, or which bit of the puzzle crashes, but usually running that once a week is just easier ☹


I just grokked the code from sourceforge. It boils down to:

display some tray icons based on live data from /proc
access some /sys/devices/
toggle bluetooth, display, wlan, sound via, you guessed it, /sys
execute some bash scripts that write some hard coded data to /sys and /proc for battery and power, touching laptop_mode, and some usual suspects that are all either recommendations by powertop or easily found on the net.
Interestingly assumes all graphics are radeon and all sound is snd_hda_intel, but does no harm if they aren't.

Not really rocket science but one may derive the one or the other hint for improving any default power manager that only switches the governors.


connect to windows share automatically and rsync

Your command is not complete, try something like this:

rsync -Paz -e ssh /home/chris/ root@192.168.1.65:/LinuxHome/

To connect to your Box without giving a Password create an authorized_key. You can find a Howto hiere: http://sshkeychain.sourceforge.net/mirrors/SSH-with-Keys-HOWTO/SSH-with-Keys-HOWTO-4.html

Copy your public key in the "Key"-Field of you WC configuration. Don't change anything, just copy it like it is. When it works you should connect with your Key and you won't be asked for a password while connecting.


What is the minimum secure length for gpg -c file.txt?

How you generate your passwords is important. You've chosen three words and a small number for your example, and I'm guessing the three words were chosen from a list of hundreds of words, maybe two thousand. (At least I seem to have '2000' in mind as the average person's daily vocabulary.)
Choosing a word at random from 2000 gives you around 11 bits of entropy. Three such words would be 33 bits. Your number 32 is five bits long, so lets pretend it contributes the full five bits. That's 38 bits of entropy, under some very generous assumptions. Modern GPUs can approach this size problem in a second or so, though I don't know if GPG's -c option is covered by existing tooling or not. Anyway, I think your example passphrase is not useful for anything important.
Here's a tool I got from a friend, Aaron Toponce. It's possible I've extended it a bit, so any bugs remaining should be considered mine:
gen-pass(){
        echo "Generating passwords with 80-bits of entropy"
        [[ $(echo "$1" | grep -E '[0-9]+') ]] && NUM="$1" || NUM=1
        for I in $(seq 1 "$NUM"); do
                strings /dev/urandom | grep -o '[a-hjkmnp-z2-9-]' | head -n 16 | tr -d '\n'
                echo # blank string
        done | column
}

You use it like this:
$ gen-pass
Generating passwords with 80-bits of entropy
fx6kycwsktr8v5gq
$ gen-pass 10
Generating passwords with 80-bits of entropy
re784jv4ha9-sxmn    ju68qfwwtc88p4cu    9s-m5fv7rg34fgnt    3vazc9hqs2ypk8wr    ncceast25bv972h9
gemaq873n7funqnr    jj6sq5zwkbmnh9jt    s2whnmzv435gdvd6    sctxjk97tb4bar6q    3qvtkg9-d32cd8ch
$

The grep -o is complicated to skip 'difficult' characters like i1l o0. Because there are 32 characters selected, each one provides five bits of security: sixteen characters time five bites each gives a total of 80 bits of security. This is significantly lower than usual AES keys, with 128 bits of security, but it is an approachable size for people. You can amend the '16' in the example to reach whatever security margin you need. (It'd be nice to update the output, as well, to make sure you know what you're getting when you use it.)
Using this, or another tool like it, that generates passwords using an algorithm designed to output a password with specified properties, is much safer than trying to be random yourself.


Ubuntu 14 Installed on External Hard Drive Random Crashes

I have fixed the problem by opening the NVIDIA X Server Settings application and changing the graphics profile from NVIDIA to Intel, but thanks for the other answers.


How to make Atomic Pi with Ubuntu 18.04.2 and Chrome play YouTube videos

If you install Lubuntu 19.04 it will work without any config mod's.  HDMI audio works from the start and Youtube videos play well.  It's possible HDMI audio works with v19.04 also with other desktops... Ubuntu, Xubuntu, ext.
If you have to use 18.04 then probably, to at least get audio working, you will have to modify things via "Linuxium ISO respin script" or manually change the installation/configuration.


How do I completely remove Ubuntu 12.04 on my Mac?

Since you're switching back to Ubuntu 10.04 LTS, you won't want to expand your other OS (I am guessing it's Mac OS X) to fill up the space that had been used for Ubuntu's partitions, because you'll just be installing 10.04 after removing 12.04. This simplifies things.

It is a good idea to actually remove the partitions though, to ensure that Ubuntu 10.04 LTS's installer sees unpartitioned space that it can use.

Boot from the Ubuntu 10.04.4 LTS installation CD/DVD or USB flash drive. (It's worth getting that point release's installation media even if you have the original 10.04 LTS installation media or media for an earlier point release.) Select Try Ubuntu without installing (not Install Ubuntu).

Make sure to back up any data in your Ubuntu partitions, as you'll be deleting them and it's a hassle (and sometimes impossible) to recover data from a deleted partition. It's also a good idea to ensure your backups of documents and other important files in your other OS's partition are current. This is less necessary since you won't be resizing that partition, but you could still make a mistake.

Open GParted (System > Administration > GParted Partition Editor). The Ubuntu partitions are of type ext4 and linux-swap (or, if you started with a very old Ubuntu system, ext3 and linux-swap). Remove them, but make sure to keep other partitions. (These other partitions are probably, but not necessarily, of type hfs+, since that's what Mac OS X uses. If your other OS is Windows, then its partitions would probably be ntfs.)

After removing those partitions, click the green check mark to apply your changes. Wait for it to finish. Then quit GParted. Double-click on the Install Ubuntu icon on the desktop, and this will start the Ubuntu 10.04.4 LTS installer. When you install, make sure not to tell it to use the whole disk, as this would wipe out your existing (Mac OS X?) operating system.


Installing Atom on Ubuntu encounters errors with gvfs-bin

Known issue with package depending on deprecated no longer available gvfs-bin.
Been fixed in beta and nightly.
If you still want to install atom release 1.52.0 on newer Ubuntu, then download the deb package and install with:
sudo dpkg --ignore-depends=gvfs-bin -i atom-amd64.deb


Once it gets rebooted and retuerns to the login screen. Login through the root and use the below command,

shutdown -h now

This will helps to shutdown the machine.


This is an issue caused by incompatibility of the default Ambiance theme with the Nautilus version.

GNOME developers love to break this and that between GTK releases. Since Ubuntu 16.04 is shipped with mostly GTK 3.18 components including nautilus, updating the nautilus and GTK with break the compatibility of those applications with default Ambiance theme.

You need to downgrade to default nautilus and GTK. I think you've added gnome3-staging PPA.

So, remove it with this command

sudo ppa-purge ppa:gnome3-team/gnome3-staging

If you prefer to stay with GTK 3.20 in 16.04, You have to find themes that work well with GTK-3.20.

The list of themes that supports GNOME 3.20 is few. Here is a list

Arc theme. Use their github page https://github.com/horst3180/arc-theme or Noobslab PPA https://launchpad.net/~noobslab/+archive/ubuntu/themes
Numix theme. Use the above PPA

If you want to use default Ambiance theme:

If you really want to use the Ambiance and Radiance theme, you can download the light-themes package from Yakkety release and install it in 16.04. It works fine in my test.

Download it from here http://packages.ubuntu.com/yakkety/all/light-themes/download
Install it using following command while you're on the directory of the downloaded deb file.

 sudo dpkg -i light-themes*.deb


Xubuntu/xfce Some .txt files won't open text editor

Same issue with Mint Mate 18.1, text files created on this computer open normally with a double click. Text files copied from another computer when double clicked do nothing. Only way I've found to make it work right is to do a save as to the desktop, then overwrite the old file with the new one.


New user can't login from FTP in ubuntu server 14.04

On server machine:

sudo service proftpd restart

then

netstat -tpan | grep 21

make sure proftp is open on the server machine on 0.0.0.0 or public ip

Use

nmap my.server.ip.num

from the client machine to make sure the port is open (21).


How do I install drivers for an HP  LaserJet Pro P1102w?

Your particular printer is supported via the hplip library.  Unfortunately, the version by default in lucid is too old for your printer - lucid has version 3.10.2 and you require at a minimum v3.10.4

There is a "untrusted" PPA on launchpad with the latest version which you can install - this is from the hplip development team.

If you install this PPA, it will upgrade your lucid hplip library.  Next time you plug in your printer it should then be recognised correctly.

The PPA's name is: ppa:hplip-isv/ppa, you need to add it to your software sources, which you can do by following these instructions:

What are PPAs and how do I use them?

Or via the command line:

sudo apt-add-repository ppa:hplip-isv/ppa
sudo apt-get update
sudo apt-get hplip

Related Questions:

 Are "PPA's" safe to add to my system, and what are some "red flags" to watch out for?
 How to install ppa packages in an apt-get style


Problems with ttf font rendering under LibreOffice

Fonts like Calibri and Cambria resort to using embedded bitmaps when adjusted to small sizes.

To disable this font behaviour, put the following into $HOME/.fonts.conf:

<match target="font" >
     <edit name="embeddedbitmap" mode="assign">
         <bool>false</bool>
     </edit>
</match>

Create the file if it doesn't exist.

Restart to take effect.

Sources
http://ubuntuforums.org/showthread.php?t=724818 (registration required)
http://manpages.ubuntu.com/manpages/precise/man5/fonts-conf.5.html

NOTE:
$HOME/.fonts.conf is deprecated in Ubuntu 12.10
Instead, paste the above XML code (as root) in /etc/fonts/conf.d/50-user.conf


Can't remember which partition Ubuntu is on

The Ubuntu partition would be formatted in ext4, but none of your screenshots show one.

I would guess it was installed on the 11.61GB partition, and OS-Uninstaller formatted it as NTFS. You can go back to Windows, delete the 11.6GB and 7.9GB partitions, and expand C into the empty space. (The 7.9GB partition was Ubuntu's swap space.)


I don't have first hand experience on the nm-applet disappearing from MATE panel issue, but it was answered here :

Can’t get network applet back in Ubuntu MATE 18.04

Ubuntu 18.04 LTS includes network-manager-l2tp in the default repo, there is no PPA repo that needs to be added.

Unless you are using KDE, you also need to install the GNOME based connection editor component with :

sudo apt install network-manager-l2tp-gnome

To avoid Ubuntu bug LP#1778946 which breaks DNS resolution after disconnecting the VPN connection, install the resolvconf package :

sudo apt install resolvconf


Install docker on Ubuntu 16.04: Unable to locate package docker-ce

It's not working because the Ubuntu installed is a 32 bits one (as you can see from the repo image, it's the i386 one).
And the installation guide from Docket clearly states:

OS requirements
To install Docker, you need the 64-bit version of one
of these Ubuntu versions:

Yakkety 16.10
Xenial 16.04 (LTS)
Trusty 14.04 (LTS)

I've installed a 64 bits, and all works correctly.


18.04, Slow boot and black screen on boot before reaching login splash

From the comments...

The 4.15.0-24 kernel is known to have some problems. To see if that may be a part of your problem, try moving the mouse during slow boot up, and see if it boots faster/normally.

If that improves the boot time, boot to a prior kernel like 4.15.0-23, and/or wait for a newer kernel to arrive.

Update #1:

Edit /etc/gdm3/custom.conf and change:

#WaylandEnable=false

to

WaylandEnable=false

and see if that helps.


Having to log In twice after screen lockout

After enough updates with "sudo apt-get update; sudo apt-get upgrade" and reboots, Ubuntu finally must have fixed this bug because I no longer have to login twice after a screen lockout timer engages from the screensaver. Also, it used to be that Chrome would lockup on the keystrokes after unlocking a screen, but that problem went away as well. Also, I appear to still be on the same kernel as when the problem occurred: kernel 2.6.32-29-generic.


Having some trouble on how to Build MEX-function from C/C++ or Fortran source code in MATLAB2015 ubuntu

You need to install -dev packages for stdc++ library:

sudo apt install libstdc++-4.8-dev libstdc++-5-dev

and do not forget to install build-essential package.


The issue was resolved VIA Chat in the comments.  The steps were:

1) Boot to live disk
2) Select Try Ubuntu without installiing
3) Hit e to edit the grub commandline
4) Replace "quiet splash" with "nomodeset"
5) Hit F10


How to create a LVM Partition/physical volume > 2TB

It seems that by creating a partition to use as a physical volume in LVM, we're limited to a 2TB volume size. This is due to the limitations in the legacy MSDOS partition table system managed by fdisk and why one should use GPT.

Fortunately, LVM also understands plain devices without a partition table. This has the drawback that you'll have to use the whole device as physical volume, but that's exactly what I want to achieve.

To erase the current partition table execute the following command (Warning: this effectively erases all contents on the disk!):

sudo dd if=/dev/zero of=PhysicalVolume bs=512 count=1

replacing PhysicalVolume with your device path, e.g. /dev/sdb. Then run

sudo partprobe

to let the kernel re-read the new now non-existing partition table.

Now actually format it as an LVM physical volume:

sudo pvcreate PhysicalVolume

(again, replace PhysicalVolume with your device path)

This is based on the information mentioned in the manpage of pvcreate:

DESCRIPTION
       pvcreate initializes PhysicalVolume for later use by the Logical Volume
       Manager  (LVM).   Each  PhysicalVolume  can  be a disk partition, whole
       disk, meta device, or loopback file.   For  DOS  disk  partitions,  the
       partition  id  should  be  set  to 0x8e using fdisk(8), cfdisk(8), or a
       equivalent.  For whole disk devices only the partition  table  must  be
       erased, which will effectively destroy all data on that disk.  This can
       be done by zeroing the first sector with:

       dd if=/dev/zero of=PhysicalVolume bs=512 count=1


All files erased after installing Ubuntu

After a partition table has been accidentally overwritten you will need Data Recovery Tools to restore the remainders of your data. Mind that the likelihood for successful recovery decreases with every write access to your harddisk. Therefore best advice is to run these tools after booting from a live disk.

By installing

testdisk

you may be able to recover whole partitions. Included in the TestDisk suite you will also find the tool PhotoRec that helps to recover individual files even in the case a partition can not be restored or the drive itself has a hardware defect.

Reading the TestDisk Wiki or PhotoRec Wiki is highly recommended


I just found myself in the same situation with the same problem trying to install MATLAB r2014a in a clean ubuntu 14.04, the solution I found it in a post that said that was problem with the java jre

This worked for me:

./install -javadir /usr/lib/jvm/java-7-openjdk/jre/

I know you solved with a other iso, but I think someone else can find themselves with the same problem I could be interesting for them.


Instead of "Install Ubuntu beside Windows 8," select the option called "Something Else." This will enable you to manually specify your partitions. See this page for details (scroll down to step #7-C). (This guide refers to Ubuntu 11.10, but I'm pretty sure there haven't been huge changes in the intervening releases.)


Why are some systemd services in the "masked" state?

mask is a stronger version of disable. Using disable all symlinks of the specified unit file are removed. If using mask the units will be linked to /dev/null. This will be displayed if you check e.g. by systemctl status halt.service. The advantage of mask is to prevent any kind of activation, even manual.

Caution: systemctl list-unit-files is listing the state of the unit files (static, enabled, disabled, masked, indirect) and has nothing to do with the state of the service. To have a look at the services use systemctl list-units.


Can I set a specific group|umask to be the default one for all actions within a certain path?

Partial answer:

Add the setgid bit on the parent directory:

sudo chown redsandro:www-data /var/www
sudo chmod 2770 /var/www

alternately:

sudo chmod u=rwx,g=rwxs /var/www


If a ssh-server has been installed on your server (most of the time a ssh server is installed on servers) you can access it using ssh command.

ssh urusername@urserverip

If you can access it using ssh you can change your password or add a new user (You can do all the administration work).


Ubuntu 18.04 freezing after login, only mouse movement working

You've got a problem with your swap partition.

Screenshots or images make it a little difficult to give a 100% complete answer, but I'll give you the basics and that should be enough.

The /etc/fstab has a line where it tried to mount swap. It fails because the UUID that ends in c932 is incorrect. We have to edit /etc/fstab and replace that incorrect UUID, with the UUID that we see in the sudo blkid command... using the /dev/sdb1 UUID that ends in 18cf.

Boot to recovery mode and enter this command(s):

sudo mount -o rw,remount / # assure the disk is r/w

sudo blkid | grep sdb1 # show us the correct UUID

copy this UUID to the clipboard

sudo pico /etc/fstab # edit fstab

replace the bad UUID on the swap line, with edit/paste

control+o and return to save the edit

control+x to exit the editor

reboot # reboot the computer


Windows 8.1 is Completely Blocking Ubuntu

I think Windows has re-written your main disk's first sectors, to put its own boot loader back on. You need to reinstall GRUB on this disk, by running these commands from a Ubuntu live CD :

Adapt! Select your main drive. Use fdisk -l as root to find out its device file.

grub-install --recheck /dev/sda
grub-mkconfig -o /boot/grub/grub.cfg
update-grub # May be useless.

If you need a way to access your BIOS (to boot on the Live CD for instance), have a look here maybe :

http://guidesdna.com/complete-guide-dual-boot-windows-88-1-ubuntu/
Will upgrading Windows 8 to 8.1 affect Ubuntu?
Install Ubuntu 13.10 in dual boot with Windows 8.1
Grub not showing on startup for Windows 8.1 Ubuntu 13.10 Dual boot
http://ubuntuforums.org/showthread.php?t=2167155

Your main challenge is to reach a Ubuntu Live install. Windows messed up the boot procedure, as it always does. Try not to be messy : Windows got control of your boot, you don't want to piss it off.

By the way... Being unable to reach Ubuntu doesn't mean you can't reach its partitions from Windows. However, you need to assign them a letter and access path using the Windows disk management utility.


I have the A6-3400m APU (integrated 6520G, discrete 6470M) and my experience until now is:

The Ubuntu built-in "radeon" driver does NOT support "dual graphics". To get the radeon driver without dual graphics work properly, the discrete graphics card should be switched off in the BIOS (less power consumption, ...)
AMD provides a proprietary driver called "fglrx". This driver can be installed via the system settings "additional drivers" or the latest version directly downloaded from AMD. https://help.ubuntu.com/community/BinaryDriverHowto/ATI My experience: The Ubuntu fglrx version is much toooo old: I had a lot of problems with wine and the activated discrete graphics card because that driver recognised a wrong graphics card (7400m series instead of 64oom series). With the latest AMD driver (Catalyst 12.10): working.
The fglrx drivers for Linux/Ubuntu are provided with a graphical configuration application called Catalyst Control Center and can also be configured via command line via amdconfig. With both configuration tools it is possible to switch between the discrete und the integrated graphics engine. This is called PowerXpress. With Windows this switch can be done without reboot but X needs a restart. Therefore the powersaving feature called PowerPlay does not use PowerXpress under Linux but just other features like dynamic clock rate change, .... BUT: PowerXpress is NOT "dual graphics".
"dual graphics" means: Both graphics engine act like a single one using the CrossFireX-Technology. This is provided for Windows 7 DirectX 10+ but NOT for Windows XP or Linux! For more information compare the AMD dual graphics FAQ: http://www.amd.com/us/products/technologies/dual-graphics/pages/dual-graphics.aspx#4

If there is any newer information about dual graphics and Linux: Please let me know!


gnome-terminal: can't access url from the terminal by single click

Press Ctrl whilst clicking on the link.

You can also right-click on it and press Open Link

It that does not work, try running man -Tutf8 dropbox to output the manual page to stdout


GPG error: http://archive.cronical.com trusty InRelease: Clearsigned file isn valid, got 'NoDATA'

"cronical" should be changed to "canonical".

Do the following in terminal:

sudo sed -i s/cronical/canonical/ /etc/apt/sources.list


I found the following work around from 2010:

change the following lines in ~/.xournal/config

highlighter_opacity=.99
startup_tool=highlighter
highlighter_color=black
highlighter_thicknesses=0.85;1.41;2.26

This changes the default tool to highlighter, makes the color black, opaque and gives it the same thicknesses as the pen tool.

Here's where this was suggested:

http://sourceforge.net/projects/xournal/forums/forum/554376/topic/3867709?message=8665099

Maybe I should submit a feature request.


It sounds like you need to download a proprietary driver for your wifi.

Go to Settings > Additional Drivers, and see if there's an option to install driver software for your wifi. You will have to be connected through ethernet to download the driver, though.


Logitech MX Anywhere 2 mouse won't stay connected

I can't speak to the Logitech problem, but the solution in my case to the bt-device -i assertion errors was to use blueman-applet to disconnect, untrust, and then finally remove the device. Using bt-device to remove did not work.

I then re-paired the device and bt-device -i was happy again.


How to Control Backlight and Set Max Limit Brightness in Display of Ubuntu 16.04?

I can't get gsettings to change the brightness on my laptop running Ubuntu 16.06, but I can change the brightness by storing a value in /sys/class/backlight/device-name/brightness where device-name is one of the video devices listed in /sys/class/backlight.  In each of these directories there is a max_brightness file. To write to these files you will need to be root.  So in my case, using the first of the 3 device directories (which in my case is acpi_video0),

$ ls /sys/class/backlight    # shows the video devices
acpi_video0    acpi_video1    radeon_bl0
$ cat /sys/class/backlight/acpi_video0/brightness   # shows current level
7
$ cat /sys/class/backlight/acpi_video0/max_brightness   # shows max level
10
$ sudo sh   # become super-user
# echo 3 > /sys/class/backlight/acpi_video0/brightness   # dim screen
# echo 10 > /sys/class/backlight/acpi_video0/brightness   # max brightness
# exit   # return to unprivileged user
$ sudo sh -c "echo 10 > /sys/class/backlight/acpi_video0/brightness"

The final line above gives a "one-liner" brightness change command.

You could extend this if desired to compute a fraction of brightness required based on max_brightness using the expr command.

P.S. My laptop is an Intel Compaq CQ62 so this may not solve the problem on a Macbook.


What is wrong with this method of using an alternate lock screen background?

This is only possible in Gnome 2. In newer versions, the background picture in the lockscreen will always be the same as the background of the user currently logged in.


Use

sudo start lightdm

to start the graphical login screen an then do a normal login.
Use

sudo stop lightdm

if you want to disable the GUI again.


You're doing it all right. Make sure that this address is not overridden later in the configuration file.

You should restart openVPN by executing:

sudo /etc/init.d/openvpn restart

Restarting server.conf only is possible with:

sudo /etc/init.d/openvpn restart server


How can I redetect swap partition after formating to enable hibernation

Yep, it must be greater or equal RAM size (let it strictly greater).
Partition shrinking needs to move some data blocks. It's up to you to backup or to take the risk. However, 2GB is considered a short time operation, if it is taken from the end of partition (ie sda2). If it was from the beginning of a large partition (example: sda4), my advice forget it.
To fix the hibernation

Get the new UUID

sudo blkid

Update the resume configuration file with the correct UUID

gksu gedit /etc/initramfs-tools/conf.d/resume

Update RAMDisk

sudo update-initramfs -u

Reboot

Reference: Community Wiki: Swap FAQ


Ubuntu 14.04 with Android 6.01 - MTP failing

==========================================================================

CONCLUSION:

The problem was on the mtpfs, when I change it with jmtpfs my problem has been resolved.

The solution came from this guide which apparently is in German, but don't worry just follow the commands.

If you can't compile the jmtpfs just run the folloing command on the terminal and skip the compile of the jmtpfs, it worked for me like that:

  sudo apt-get install jmtpfs

and then follow as normal the rest of the command on the guide and it will work just fine...

I hope that helps someone...


Windows 10 Uefi removes Ubuntu Grub after each boot

Boot into Win 10, then open Command Line with Admin privilege (to do so search for command in the start menu and right click and select Run as Administrator), then run the following command:

bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi

It will fix you issue, as you add grub path to windows boot manager.


Openshot 2.2 uses all my cpu and freezes

Video editing is a very memory intensive operation, so you are probably running short of memory and swap space. Try running top while loading and previewing the video.

Adding more swap will make the system run better, at least for some time. But heavy paging / swapping to disk generates a high load on your disk (the same disk as you are reading the video from) so a better solution would be to add more memory.


Firefox 9.0 loads Apps tab despite preference not to load tabs

I can confirm this on Firefox 9, 10, 11 and 12. On Firefox 8 pinned tabs are not loaded. I recommend taking a look at https://bugzilla.mozilla.org to see if anyone else already reported this and to create a new bug report. It could be the intention of the devs to automatically load pinned tabs, but it could also be a bug.

The only preferences I am aware of are browser.sessionstore.restore_hidden_tabs and browser.sessionstore.restore_on_demand. The first controls tabs on hidden panorama groups, which means any group not currently in display. The second one controls the tabs on the active group.

Bug:

https://bugzilla.mozilla.org/show_bug.cgi?id=708585

Related bugs:

https://bugzilla.mozilla.org/show_bug.cgi?id=688962

https://bugzilla.mozilla.org/show_bug.cgi?id=674452


Inconsistence between CLI command and nautilus units

It works like this:

From man ls

  -h, --human-readable

  with -l and/or -s, print human readable sizes (e.g., 1K 234M 2G)

  --si   likewise, but use powers of 1000 not 1024

and

  The  SIZE  argument  is  an  integer and optional unit (example: 10K is 10*1024).  Units are K,M,G,T,P,E,Z,Y (powers of
         1024) or KB,MB,... (powers of 1000).

I think the commands work like they should, as illustrated by the following examples (running in 16.04 LTS)

$ ls -l ubuntu-17.10-desktop-amd64.iso
-rw-rw-r-- 1 olle olle 1501102080 okt 19 16:09 ubuntu-17.10-desktop-amd64.iso

$ BLOCK_SIZE=h ls -l ubuntu-17.10-desktop-amd64.iso
-rw-rw-r-- 1 olle olle 1,4G okt 19 16:09 ubuntu-17.10-desktop-amd64.iso

$ BLOCK_SIZE=si ls -l ubuntu-17.10-desktop-amd64.iso
-rw-rw-r-- 1 olle olle 1,6G okt 19 16:09 ubuntu-17.10-desktop-amd64.iso

$ ls -lh ubuntu-17.10-desktop-amd64.iso
-rw-rw-r-- 1 olle olle 1,4G okt 19 16:09 ubuntu-17.10-desktop-amd64.iso

$ ls -l --si ubuntu-17.10-desktop-amd64.iso
-rw-rw-r-- 1 olle olle 1,6G okt 19 16:09 ubuntu-17.10-desktop-amd64.iso


If you are using g++ as your compiler, you should compile your program with the -g -O0 flags, to facilitate debugging.


how to create a hot-key to control a volume app

I assume you want to control volume up and down with a key combination.

try adding these entries to All Settings->Keyboard->Shortcuts->Custom shortcuts by clicking +:

Volume down: amixer -D pulse sset Master 5%-

Volume up: amixer -D pulse sset Master 5%+

Assign the key combination you want by clicking on the above two entries.

This will be helpful: https://help.ubuntu.com/stable/ubuntu-help/keyboard-shortcuts-set.html


How to activate IPv4 address on physical Ubuntu Server on home network?

My best guess from searching through help forums is that either the home router is not correctly serving the IP address or the machine itself is not properly receiving/configuring the address.

The IP's you posted (10.0.1.27) is RFC1918 address, commonly known as private IPs. They are commonly used for NAT.

You have a router that performs NATing in front of your computer, which explains the behavior. To get a public IP at the Linux machine, you have to turn of the NAT function of your router. Please refer to the manual of the router for instructions on this.

Alternatively, you may use port forwarding to forward traffic to the machine in question.


Try reinstalling indicator-sound

sudo apt-get install indicator-sound


rsync from one server to other takes more space

As described in the Storage Requirements section, ghe-backup uses hard links. A hard link is when one file is listed more than once, either under different names or in different directories. They look like two different files, but really the data is stored only once.

Rsync by default doesn't look for this, so it ends up copying the file completely each time it's listed. You need to add -H to your rsync options to tell rsync to look for this and handle it correctly. Note: doing this is much slower and often requires quite a bit of RAM, so be warned it may take longer than you'd expect.


Read the man-page. In a terminal write man which ...

DESCRIPTION

   which returns the pathnames of the files (or links) which would be exe‐
   cuted in the current environment, had its arguments been given as  com‐
   mands  in a strictly POSIX-conformant shell.  It does this by searching
   the PATH for executable files matching the names of the  arguments.  It
   does not canonicalize path names.


laptop monitor brightness always maximum upon charging

To reduce the brightness of you screen by manually is xbacklight is requied open your terminal and type this

  sudo apt-get install xbacklight

and then type

  xbacklight -set 50

there 50 stands for brightness range we can get it upto 100 from 0.
you can also increase and decrease the brightness from present value to specified level.as you mentioned if you want to increase to 10% from current value of brightness then should give this

  xbacklight -inc 10

to decrease

  xbacklight -inc 10

Refer this web page is one of the way to reduce brightness manually
(http://ubuntuhandbook.org/index.php/2014/04/save-screen-brightness-settings-in-ubuntu-14-04/)
or
try this In some cases the brightness may be controlled from

  /sys/class/backlight/acpi_video0/brightness

as is the case with dell vostro 3400 and the brightness range is 0-15. You may  have to look for other folder in

  /sys/class

if the same path may doesnot exit.


Corrupted Partition Table in Ubuntu Natty

It's hard to know precisely what's happened. I suggest that perhaps the UUID (unique identifier) of the partition has changed with your playing around but it might be broken more than that.

Whatever happens, you'll need an Ubuntu CD. It doesn't have to be the same version as what you currently have installed, but it might help. Burn that to CD/USB and then boot to it.

The next bit is fairly simple. Install boot-repair by opening a terminal in the live environment and firing this off:

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair-ubuntu

Then run it from the applications menu. For more help using boot-repair, follow this guide but it's pretty simple.

If that doesn't help, something is more screwed up than any of us would like. There could be partition damage so check to see if you can access it (again, from the LiveCD). If that works, I'd be tempted to rescue any data I might need and reinstall Ubuntu. It's probably faster and cleaner than trying to bodge it back into life.


How to boot ubuntu 20.04 from external hard drive on a machine with no internal hard drive

Installing to External Drive
If you are installing Ubuntu on External Drive it is nice to create a disk that will boot on either BIOS or UEFI machines,
The method on this Link: Easy Full Install USB that Boots both BIOS and UEFI is very simple to install, Just download the image file and use your other computer to flash it to the external disk using Rufus or Etcher in Windows or dd, Disks or mkusb in Ubuntu.
A more complex method, starting from scratch, can be found here: How to Create a Full Install of Ubuntu 20.04 to USB Device Step by Step


Ended up using AutoKey and works perfectly


Unable to start VMWare Workstation after upgrade to 13.04

Hit same problem here with Ubuntu 13.04 last month.  At the time, upgrading to VMWare player 5.0.2 build-1031769 solved the problem.  Fast forward a month, hit a new problem today after recent 13.04 updates, again VMWare would not start.  Latest VM player version is still 5.0.2.  Google lead me to this explanation:

http://communities.vmware.com/thread/446490?start=0&tstart=0

Running the following vmware command with root privs solved the problem for me:

sudo vmware-modconfig --console --install-all

HTH


Nvidia GPU slows down when laptop is plugged to AC

This is just an informed guess, but on battery power your GPU is probably throttled down automatically, but on AC power it may be overheating, and that may result in even more throttling.

Alternately, being on AC the charging battery, and increased CPU clockrate are going to increase the internal heat generation, and the overall internal temperature inside the chassis is probably hampering the cooling of the GPU.

From the command line, you can see your ambient temperature with sensors and you can see your GPU temperature with nvidia-smi.


How can I fix ubuntu winboot wubildr.mbr missing error?

The error message suggests a WUBI installation. Your computer, though, is clearly booting Windows in EFI mode, and WUBI is incompatible with EFI. Therefore, if you did a WUBI installation, it won't work.

There's also evidence on your computer of a standard partitioned installation of Linux: You've got a separate /dev/sda8 that uses a Linux ext4 filesystem and that seems to have boot files; and you've got a BIOS-mode GRUB in the disk's MBR.

Overall, therefore, my guess is that you've tried both installation methods, either intentionally or not. If so, one thing you should do is to remove the WUBI stuff. I'm not an expert on WUBI, so I'll just leave it with that link. Removing WUBI won't solve your basic problem, though; the point is to not waste disk space and to simplify the configuration so you're less likely to get confused in the future.

Assuming your Linux installation on /dev/sda8 is more-or-less complete, you're faced with the problem that you've got a mixed-mode installation -- Windows is booting in EFI mode, whereas Linux is set up to boot in BIOS mode. This can be awkward at best, so you should probably convert Linux to boot in EFI mode. You can do this in many ways, but either of the following is likely to be easiest:

Boot a live CD-R or USB flash drive in EFI mode and run Boot Repair. This should get GRUB up and running with Windows detected. The trick is forcing an EFI-mode boot of a live CD. You may need to play with your firmware's boot options. Typically, hitting a function key (which one varies) produces a boot menu, and you should select the one for your live CD that mentions "EFI" or "UEFI."
Download the CD-R or USB flash drive image of my rEFInd boot manager and prepare a medium with it. You should then be able to boot to it. If rEFInd lets you boot both Windows and Linux, boot to Linux, mount your EFI System Partition (ESP; your /dev/sda3) to /boot/efi, and install the Debian-package version of rEFInd. You'll then use rEFInd to select your OS on subsequent boots.

If one of these fails, try the other one.


How to resolve dependence of libmono-winforms2.0-cil

libmono-winforms2.0-cil is available in 14.04, so the best thing to do would be to install that instead of 16.04, though it will reach EOL in about a year...


When you press Ctrl+Alt+F7, you're switching to a different tty or virtual console.

These virtual consoles work much like a Terminal, such as gnome-terminal or xterm, except they aren't loaded by your Windows Manager, and you will likely need to login to them.  Be warned, if you login and fail to log out, that tty will stay active and someone else can just switch over and use it.

That means that just like you can use other tools, such as screen or tmux to multiplex your terminal, you can do so in your tty.  One of the benefits from using one of these multiplexers is that they support multiple 'tabs', have ways to have multiple shells or terminals in a single tty or terminal window (your goals) as well as support resuming of the session later.  There a lot of guides on how to use both screen and tmux, but I would recommend you taking a look at The Tao of tmux, as that is very detailed and doesn't assume you know a lot about everything else.  There are images there that will help explain how you can split your tty into multiple terminals, and how to switch between them.

If you wish to automate something for when you login, you will want to look into how sourcing files at login, such as ~/.bashrc, ~/.profile and other shell initialization files work, while also looking into how others have solved similar problems.

Without more specifics, I hope that this helps explain that you can use a multiplexer that supports splitting to accomplish your goal.


"uninstall" Ubuntu, delete partitions and install FreeDos

First you will need to use a tool like gparted to delete all linux partitions and replace them with a FAT16 partition since the FreeDOS installer, unlike the ubuntu installer, does not give you the option to modify partitions.

From http://freedos.sourceforge.net/wiki/index.php/Install:

  Installing on a physical PC

  Boot from an existing DOS, from one of the cdroms, or from the special
  boot diskette. In the latter two cases, simply follow the menus to
  install DOS. In the former case, you will first have to make sure that
  the cdrom can be accessed. You can also use the ISO images directly
  instead of using a real cdrom. See above for details.

  If your computer has no partitions with FAT filesystem yet, you will
  have to create one before you can install DOS. For example GPARTED
  which is included with many Linux distros and many Linux versions
  which can be run directly from CD or DVD (no installation of Linux on
  harddisk needed) can resize your existing NTFS Windows partitions to
  make space for DOS without having to reinstall Windows. FreeDOS will
  need one FAT type partition: This can be FAT12, FAT16 or FAT32, but
  FAT16 is clearly the recommended choice: FAT12 is too small and FAT32
  is hard to boot from. You can use Windows or Linux to create and/or
  format the partition, if needed. Of course you can also use the
  FreeDOS install cdrom for that, but as this cdrom does not allow you
  to resize existing partitions, you should better use other tools. If
  you already do have a FAT partition, you can skip all the partition /
  format steps.

If you still have the usb drive or disc you used to install ubuntu just pop that in, start a live session from the install medium (select try ubuntu) and open gparted from there or you can create a stand-alone gparted boot medium following the instructions found here: http://gparted.org/liveusb.php#linux-setup.

The next step should be pretty self explanatory from within the program:

Delete all unwanted partitions (in your case that would be all partitions of type ext4 and swap)
You'll see a grayed out area of 'unallocated' space grow as you delete partitions
Select the unallocated space and create a new FAT16 partition on it
Apply the scheduled operations (green checkmark icon)

Now you should be all set up to reinstall FreeDOS from an install medium of your choice.


Is anything listening on port 8888? If nothing is listening on the port you can't connect to it.

You can check if anything is listening on that port with

sudo netstat -tulpn

The port is likely open already as linux firewalls won't block localhost if you don't ask them to block it.


How to build wil6210 driver from source code from Git

In order to compile only a specific module form the kernel source code you need the following command. Check this

Basically you need to cd to wil6210 code directory and run the following command:

make -C /lib/modules/$(uname -r)/build M=$(pwd) modules

Make sure to change the $(uname -r) to your target kernel version, i.e. the kernel version of the system you want your wil6210 module to work on


Application icons can be found in the directory /usr/share/applications

To remove them from the dash menu, you'll need to delete them. But, I would recommend moving them to another directory for backup, just to be safe.


Does Xubuntu Include Proprietary Software?

No version of Ubuntu includes proprietary software, at least not in essence. Proprietary software included are modules for certain graphics cards and wireless adapters but nothing else. You wont find codecs nor plugins, as they go against the distribution policies of said packages.


Can I install PHP on my local development machine?

Try with this command. Note the dash - at the end of the unwanted packages:

sudo apt install php apache2- apache2-bin- libapache2-mod-php7.4-


How to find processed called from a specific Terminal?

The jobs command will list all background jobs launched from the shell you type it in.


Nginx over Apache with Laravel give rewrite_mod problems

Since you are using nginx already, why not ditch Apache+mod_php for php-fpm? That avoids the need for a proxy.

After installing php5-fpm, add this vhost, and enable it with sudo ln -s ../sites-available/example.com.conf /etc/nginx/sites-enabled/

# /etc/nginx/sites-available/example.com.conf
server {
    listen 80;
    server_name     example.com;
    root            /var/www/example.com/public_html/public;

    access_log      /var/www/example.com/logs/access.log;
    error_log       /var/www/example.com/logs/error.log;

    # Disallow access to hidden files (.htaccess, .git, etc.)
    location ~ /\. {
        deny all;
    }

    # Some locations will never contain PHP files, handle it in the server
    location ~ ^/(robots.txt|favicon.ico)(/|$) {
        try_files $uri =404;
    }

    location = /index.php {
        # Disable direct access to the source code of index.php. If you have a
        # Laravel route for '/index.php', copy the @php_router block below.
        return 404;
    }

    location / {
        # Try to serve the static files, otherwise call into PHP
        try_files $uri @php_router;
    }

    location @php_router {
        include fastcgi_params;
        # If you move index.php outside public/, adjust it here.
        fastcgi_param SCRIPT_FILENAME $document_root/index.php;
        fastcgi_pass unix:/var/run/php5-fpm.sock;
    }
}


Can I log in as invisible when using empathy?

Open your Empathy Messenger . click at Edit and select Accounts .

It will open all your accounts , from the accounts  disable the people near by account .then you can set your status to Invisible .


How do I generate a package download list?

First Note that, You must have the updated package indexes (these indexes are used by package management softwares to get information about the available packages online). So, you must download at least those index files.

To do so, open a terminal and give this command. (You must have a working internet connection for this step)

sudo apt-get update

After you have the update package index files, use any of the method below:

Terminal way without synaptic

Use this command to generate an list of files needed to upgrade your system

sudo apt-get upgrade --allow-unauthenticated -y --print-uris | grep -o '\'http.*\' | tr "\'" " " > download-list

The file download-list will be created in the current folder of the terminal.

Or, If you want to generate a download script for a specific package, use this command (see the update section below for another command)

sudo apt-get install <package-name> --allow-unauthenticated -y --print-uris | grep -o '\'http.*\' | tr "\'" " " > download-list

replace, <package-name> with actual name of the package. such as gtg for getting-things-gnome etc.

You can now use this file to feed any download manager which support input files with URLs.

For example to use this file with wget use this command below,

wget -c -i ./download-list

assuming download-list file is in the current directory of the terminal. The downloaded files will be stored in the current working directory of the terminal.

Update: I've found another command to generate package download list:

apt-get --allow-unauthenticated -y install --print-uris package-name | cut -d\' -f2 | grep http:// > download-list

Credit of the updated command: answerer of this post

Graphical way using Synaptic

Synaptic package manager has built-in feature to generate package download script and you don't even need to to use wget explicitly in terminal, Only executing the script is sufficient.

The procedure is as follows

Install Synaptic Package Manager using terminal:

 sudo apt-get update
 sudo apt-get install synaptic

(First command is not required, if you have updated package index  files, If you are not sure, use both).
Then open Synaptic Package Manager by Typing Synaptic in the dash.
Select a package in the right section of the window, Right Click → Mark it for installation. Alternatively, If you want to generate an upgrade script, push the button Mark All Upgrades in the toolbar. The image below uses the second method.

When asked if you want to Mark additional required chanages, press the Mark button.

Then going to File --> Generate package download script, save the script as a file by give it a name and select a directory where to save it. Now, You have a script for package downloads.

If you want to download, Go to the scripts directory and run sh ./<script-name>. For example, if the name of the script is download-list and it is in your Downloads folder, the command is

cd ~/Downloads && sh ./download-list


Recent upgrade to 20.04 - Slow KDE Window Rendering

and everything was fine under 19.10 ? I doubt it a specific problem with 20.04 but some settings got replaced or something. I would recommend first looking at lshw -c video you can post the output editing your question. and also look at /var/log/Xorg.0.log file for warning and errors.

I don't have an nvidia anymore, but I remember there is a tool as well to introspec its performance.

you can also try to disable compositor temporarily for the sake of comparison. and also verify the rendering backend.

Update:

about the error you found in your Xorg.log, I found these very recent post about similar problem. I could not find if the solution was known yet. I hope it will help you.

https://www.gamingonlinux.com/forum/topic/4304/page=2
https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1730634.html
https://bbs.archlinux.org/viewtopic.php?id=254942

your video card might be too new?

what is the output of glxinfo -B ?


Why there is a delay between when a key is pressed and when it is accepted?

Because probably you put on the Slow Keys option from System Settings → Universal Access → Typing. Turn it off:


Screen Dimming Changed After Upgrade to 15.04?

Try editing this file:

sudo nano /sys/class/backlight/acpi_video0/brightness

May be elsewhere under /sys/class/backlight/*/brightness

source: Set brightness lower

EDIT:

Try reducing the gamma with redshift:

Reducing Contrast


Trying to remove Ubuntu-desktop with tasksel returns "aptitude failed"

I had exactly the same issue on 14.04 and managed to solve it. The reason was some broken dependencies. In my case it was Java package so I removed it and then reinstalled after running tasksel.

A one way to find broken dependency is to try to run apt-get remove ubuntu-desktop^ and see whether it will complain about unsatisfied dependencies or just list packages to remove. Make sure to select No and don't actually remove any packages with this command. It may ruin your system


Setting up Remote Access over a home network?

Ubuntu includes VNC server and client

Search for Desktop

The configuration dialog looks like this

Be sure to use a strong password and disable UPNP on your router.

Connect with the viewer using your ip address.


scp - files getting different sizes in destination folder

This has no matter with scp. This is an issue of file system and the used block size.

In simple word and as an example if you use a block size of 512 KB and you have a file 2.5MB size then this file will reserve 5 blocks.
Here when filesystem reads the size it will calculate 5*512KB=2.5MB

Now if you have the block size of  1MB then the same file of 2.5MB in size will reserve 3 blocks.
Here when filesystem reads the size it will calculate 3*1MB=3MB

read this and this for more information

Another possible reason

If the two systems have the same block size, then this may be caused by the starting sector of files.

I.e, what I mean that a block indeed in FIlesystem is a collection of many sectors. Those sectors (4 by default I think) consist the Data block.

so in case suppose

in system A the files starts from sector 1 of block 0 while in system B it start from sector 0 of block 0. then this leads to different in size since File in system A will reserve more sectors and thus more blocks and though more size


Having problems seeing my wifi Ubuntu Gnome 16.04

With a temporary working internet connection by ethernet, tethered or whatever means possible, please open a terminal and do:

sudo apt update
sudo apt install git
git clone https://github.com/diederikdehaas/rtl8812AU.git
cd rtl8812AU
make
sudo make install
sudo modprobe 8812au

You have compiled the driver for your current running kernel only. When Update Manager installs a later one, also known as linux-image, re-compile:

cd  rtl8812AU
make clean
make
sudo make install
sudo modprobe 8812au


Why did all my custom Gedit themes and language specs disappear after the 11.10 upgrade?

The new location for the language specs is ~/.local/share/gtksourceview-3.0/language-specs/ (note the 3 instead of the 2). If you put your .lang files there, they should work like they did before.

I'm not sure about the gedit themes. Are they actually gtksourceview styles? They have made the same move.

There is also an old folder ~/.gnome2/gedit on my system, and also one in ~/.local/share/gedit. You could try moving files from the first of these folders to the latter and see if that solves your issue.


It could be a router problem

Try to connect with a different router. Maybe you can test with one at your office? If it works Ubuntu isn't at fault. Now you have the following options with your router:

Try upgrading your router firmware
You might want to check if you can install an alternative OS on your router, like dd-wrt. Check this page to see if it does.

Just be careful: Errors while changing your firmware can make your router unresponsive (also known as bricking).
If all else fails, maybe it's time to buy a better router.


Problems creating click chroot for 14.10

14.10 is End of Life and is no longer supported.  As a result, it is no longer on the archive mirrors, and is not available for the sudo click chroot option to create the chroot from.

Therefore, you can't create a chroot because the release no longer exists at the repository archive the system is trying to pull from.


Ubuntu tells me I have packages to upgrade when I don't

It's a bug in initscripts, fixed in Natty, which copies the current state of motd to /etc/motd.tail. motd is dynamically generated whenever you boot but motd.tail is static (allowing a sysadmin to place some fixed information there for all users).

Deleting motd.tail will fix the issue temporarily but a better solution is to create an empty motd.tail. If the file doesn't exist then it may be created again (incorrectly) when initscripts is upgraded.

Create an empty motd.tail with

sudo touch /etc/motd.tail


The crontab file is indeed provided by the cron package. This package is installed by default (See the 12.04 Manifest).

The crontab command should already be in your $PATH:

$ type crontab
crontab is /usr/bin/crontab

Check the Official documentation to know how to set up your crontab.


For the time being, there is up to now, no way to install Ubuntu (or any Linux system for that matter) on the iPad as easily as rooting an Android. Since a year and half ago in an article about Linux running on Ipad (August 2011) there has been only small changes and steps to provide a final way of installing Ubuntu to an iPad (Or any other Mac hardware for that matter).
The team behind this, the iDroid team has a webpage where you can see their status and how far they have gotten: http://www.idroidproject.org/wiki/Status
They also provide a way called Bootlace to install the bootable part of the system (iBoot) called OpeniBoot. It currently supports only 3 devices from the different that exist.
Of course, at the end, you are limited to only accomplishing the boot part in the devices it supports. The good news is that, as far as the history of Linux is concerned, there is no ¨iCan´t¨, there is only I CAN! so in the future this could possibly be done in an out of the box manner.
Thanks to a link provided by mateo_salta, there is no legal way right now (There is a debate about it from the FSF) to jailbreak an iPad. The information can be read HERE.
For what it is worth, this is just another attempt from the DMCA to stop something they should not be stopping. If you buy an iPad, it is YOUR iPad. Maybe just hop into a plane out of the US, buy the iPad, do whatever you like with it and then come back ^^.
UPDATE: So here is some information regarding a neighbor I have that, apart from looking like Steve Jobs without the glasses, also knows about the idroidproject and has every Mac device since the palm. He showed me the iPad 1 and 2 and explained A LOT of stuff about how Mac works in regards to, let's say, blocking, ways of trying to root, jailbreak or any other word you would like to use to change how the system behaves or even change the actual system (Like installing Ubuntu on an iPad). So here are the key points that I could write about:

The iPad and any other new hardware needs to first be compatible or supported at least first with the Linux kernel. If not, then it will be very tough to get it working on Ubuntu. This creates a problem for the correct detection of the CPU, motherboard, video card, sound card, wireless card, battery detection and usage and any other hardware found on the device.

There is a strong force behind not allowing any way to be able to overwrite the actual system with another or any apps that can do this. Everything is very tight, sandboxed and checked to make sure it conforms to the way the iOs works. There are alternatives like Cydia but it needs the device to be jailbroken first.

There is a strong legal pressure from Mac to force any attempts to do something like installing Ubuntu on iPad be denied or very tough to do as one can see from the links above.

Since Mac focuses on a specific type of hardware and works only on a small group of devices (Compared to Linux on how open it is with hardware types), it makes it even tougher to guarantee that the new system, be it Ubuntu or any other Linux, will actually work correctly with all the hardware every time.

Since bootlace only works with Phone 2G, iPhone 3G or iPod Touch 1G and with a specific version of the iOs, it makes it the more difficult to get the iPad working in the present time (With all the points above pushing in on the problem)

With the slow development of the openiBoot project and seen how it can actually only detect the CPU used in the iPad as of this writing we can only see that it will be a long way until a proper boot, load and install procedure can be made to get any Linux distro into an iPad. Here is the image from the status page:

So it is sad to see such a strong wish against using Linux on this type of hardware and I should say such a good hardware indeed would actually enjoy Linux on it.
As an addition to this, today I found out about Evasi0n which is a tool used to Jailbreak several Apple devices. The download can be found here
So sorry for the negative answer and the pessimist approach I bring to it. Most of this information is thanks to a heavy Mac user that also delves himself in the Ubuntu world and knows much about this. He almost convinced me to leave Ubuntu and jump to Mac (Mac evangelist hehe) but he also made good points (From the Mac side of course) regarding the reasons behind such a close sourced way of focusing on this devices. Not my kind of answer since I tend to look for an answer but I got curious and started asking many Mac users and well.. you can see how my answer changed to a more clear one... if I can call it clear.


You do not specify the boot method, using a DVD or through USB. In either case:

the Linux kernel has loaded correctly;
I think it has located and loaded the initrd image;
it is now looking for the main squashfs compressed filesystem, and cannot locate it.

Basically, it cannot find the CD/DVD unit.

As suggested by @WhiteStone, you may have a corrupt image. To complete his reply, I would suggest getting the very latest version of Ubuntu (now 15.04), or at the very least the latest LTS (Long Term Service, now 14.04). There is no rational reason to run 12.04 on your hardware.

I have had luck with Xubuntu 15.04 on a white Macbook of similar age and specs.


You could use sed to join lines to the previous one if they start with a sequence of blank (space or horizontal tab) characters:

sed -e :a -e '$!N;s/\n[[:blank:]]\{1,\}/ /;ta' -e 'P;D' file.log

This is a minor variation of the example 40. Append a line to the previous if it starts with an equal sign "=" from Sed One-Liners Explained, Part I: File Spacing, Numbering and Text Conversion and Substitution

If the 'blocks' are separated by one or more blank lines (you don't show enough of the log to know whether this is the case) then a simpler alternative would be to use awk in paragraph mode:

awk -vRS= '{$1=$1} 1' file.log

which reads in whole paragraphs and then re-formats them with the default (single space) output separator.


Cannot login after running startx and rebooting

Step 1: at the login screen, press control+alt+F3.
Step 2: type sudo rm .Xauthority

at the login.
Step 3: run sudo reboot

you should be able to login now.

To prevent this from happining again, DO NOT RUN STARTX as root!

this will make the .Xauthority file owned by root.
If the .Xauthority file is gone, root will not have it.


Can not blacklist kernel modules in Ubuntu 15.10

This module must be in initramfs. To get it blacklisted run:

sudo depmod -a
sudo update-initramfs -u


How to fix horizontal lines on YouTube video on Google Chrome (No issue on Firefox)

If you are using 20.04,
Disabling the 'Use hardware acceleration when available' option works for me.
Open a new tab and type the following
chrome://settings/?search=hardware
Turn-off the option Use hardware acceleration when available and relaunch the browser.
Hope this helps


git-ls-files is a manual page on Ubuntu. A search with apt-file search git-ls-files confirmed it.

If you want to use git-ls-files instead of git ls-files, create a symlink for it:

sudo ln -s /usr/bin/git /usr/local/bin/git-ls-files

Unless some other program depends on this name, I'd just use git ls-files, the only difference is the first separator, dash (-) vs a space ().

If you wish to create such an alias for each git command, run the below bash command:

for file in /usr/lib/git-core/*; do name=${file##*/}; [[ $name != git ]] && [ -x "$file" ] && sudo ln -s "$file" "/usr/local/bin/$name"; done

This will create the symlinks in /usr/local/bin.


Using super+space rotates through apps in bottom

Right click on the Open Applications icon and click Parameters

Click on Settings

On the hotkey tab, look for Global hotkey for cycling through the thumbnail menu

Sorry for not finding the English version.


Windows 7 usb created using ubuntu image writter not booting

I've always just used "sudo cp isofile /dev/somedevice" where "somedevice" is the root device of your usb drive, aka sdb, sdc, etc.  Do not use the partition identifier such as "sdc1", just the device itself "sdc", or whichever one points to your device.

Some people will tell you to use dd, and that works fine, but I've had one or two experiences where dd broke a drive in such a way that it wouldn't work outside of Linux.  dd makes the entire thumb drive, no matter its capacity, look like it's a CD-ROM of the exact size of the ISO file you feed into it, so if you have a 32GB thumb drive and you dd a 2GB ISO file to it, your thumb drive will look like it's a 2GB CD-ROM device with no free space left.  cp accomplishes the same goal of putting an ISO on a USB device and making it bootable (erasing any existing data on the drive in the process), but it creates a partition for the ISO file and leaves the rest of the drive alone so it can be reused/reformatted more easily in a Windows environment.

So anyway, try "sudo cp isofilename /dev/somedevice" to put your Windows ISO on a usb stick.  For me personally, that has worked at times when other methods such as Etcher, unetbootin, tuxboot, etc. all failed to produce a bootable device.


I used a multimedia ppa and now vlc is broken

Move your vlc configuration away using this command:

mv $HOME/.local/share/vlc $HOME/.local/share/vlc.bak

Then try again.


Problem fixed! Here is how I figured out (kinda) what was going on:
After doing everything you told me to and not having any kind of success, I decided I'd fix a "minor" problem I had, which was the GRUB being in the wrong resolution.

I followed this instructions: How do I safely change grub2 screen resolution? booting on recovery and going to root terminal (also, for some reason I had to update grub in the recovery menu, otherwise nano wouldn't save the changes).

Set the resolution of the grub to 800x600 and that's it... the system boots properly now and without any kind of hassle. Thank you very much to everyone for the help! And hope this also helps someone else =D!


What data will be lost during upgrade from Ubuntu 12.04 LTS to 14.04?

Best option is to make an image of the current disk. Test it to make sure it works.

Your homefolder won't be changed, or: should not be changed.
Gimp: settings are in your home folder.
Apache, PHP, MySQL, Postgres, Tomcat: upgrades may break what you run on your machine. I can't tell it from here, it's a matter of testing. Something may depend on a function that is not available anymore, and it will break.
Backup folders and files in /etc where config files for Apache etc are located. You can backup the entire /etc folder as it's probably not too big. You need to be root to do this. Do this with tar, and be sure to preserve rights and ownership.
Cron jobs should stay the same, back them up if you're not sure.

The upgrade program may ask you what to do with the Apache config file(s): overwrite, keep? You should keep them. Same for other config files: keep them.


How to add application to startup application menu?

First you need to know the command of the application you want to start or the location of its binary.  The command of the application is usually its name.  For example, if you type firefox into a terminal it will start Firefox.

To make Firefox start on startup, open "Startup Applications" from the dash.  Click 'Add' then fill out the 'Command' field with the command for the application, in this case firefox. Or, if you know the location of the executable file, click "Browse..." and navigate to the file.  The 'Name' and 'Comment' fields are optional.


Drop to root shell (security vulnerability?)

Yes, disk encryption is pretty much the only way to go to protect your data. For example, without it and with enough physical access, one attacker can just take the disk out and put it in a external usb enclosure to read it from his system.

And setting the root password is not enough, one can boot with init=/bin/bash to bypass any checks, that's a well known trick.

So I would recommend to check the bios ( so someone cannot boot on a livecd, or at least, not without fiddling with bios ). Then you can also set a password on grub to prevent people from messing with the configuration, among other things.

That should prevent the most common attacks. Then you have more sophisticated ones like Hardware keylogger, Evil maid attack where your bootloader is replaced, etc, etc, but that's IMHO complicating the answer.

Security is a complex matter, and you have to see what kind of threat you face before choosing what you want to do.


Please do:

echo "options ath9k nohwcrypt=1" | sudo tee /etc/modprobe.d/ath9k.conf
sudo modprobe -rfv ath9k
sudo modprobe -v ath9k


How do I monitor who is loading files on my server ? (Apache PHP)

Apache has an access log that can be used to show this.
From this site:

Default apache access log file location:
RHEL / Red Hat / CentOS / Fedora Linux Apache access file location: /var/log/httpd/access_log
Debian / Ubuntu Linux Apache access log file location: /var/log/apache2/access.log
FreeBSD Apache access log file location:  /var/log/httpd-access.log

The access log shows what pages visitors viewed, the success status of requests, how long the request took to respond and the IP address of the site visitor.
To actually read the file you can use cat <path to access log>


swapfile takes a long time to "get cleared"

Short answer: if your computer is not acting very slowly, it's fine.

Linux will only get the contents out of swap if they are needed, otherwise, there's no point in loading something that isn't in use from swap into RAM, thereby reducing the cache.

A way to check if your system is being limited by swap is checking

vmstat 1

and looking at the wa column, which shows how long it takes before a process can run. Also, use a tool such as htop and see how many processes are in disk sleep(D).

Also, you should have a bit more swap. According to the SwapFAQ:

    RAM(MB) No hibernation  With Hibernation  Maximum
     256     256              512               512
     512     512             1024              1024
    1024    1024             2048              2048

    RAM(GB) No hibernation  With Hibernation  Maximum
      1      1                2                   2
      2      1                3                   4
      3      2                5                   6
      4      2                6                   8
      5      2                7                  10
      6      2                8                  12
      8      3               11                  16
     12      3               15                  24
     16      4               20                  32
     24      5               29                  48
     32      6               38                  64
     64      8               72                 128
    128     11              139                 256

If you have 16GB of RAM, you should have between 4GB and 32GB


How to overide internet website using local Apache2 hosted website?

You have to add it inside the hosts file, which is located in /etc.
Open it with your favorite console text editor (with root privileges by adding sudo in front of the command) and add the following text on a new line

127.0.0.1 test.com www.test.com

For example if you use mcedit the command will be:

sudo mcedit /etc/hosts

This assumes that apache is also running on the local interface (as it is by default). If you have disabled this functionality, you have to change 127.0.0.1 with the IP address apache is working on.

You can test  if everything works correctly with the ping command ping test.com


How do programs make it into the Software center?

There are two ways for an app to get to the Software Center:

It could be part of the normal repositories: Main, Restricted, Universe and Multiverse. The first two are maintained by Canonical. Universe and Multiverse are a community effort. The best way to land there is to either convince Canonical or Debian that your program is valuable.
You can add it through the Canonical developer program. This works quite similar to Apple appstore. You will need to provide the source code and Canonical will review it. This is also the only way to add pay apps.

PPA's are no way related to this, they are independent, they get no review but from the person who set it up. Sometimes, Canonical workers, or package maintainers (the members of the community responsible for some part of the Universe and Multiverse package) can setup a PPA (the Mozilla team does), then some packages from this PPA will likely become official packages. But most of the time complete independent people set a PPA, they have no review policy and their packages will never be part of the official repositories.


How to know if the router is internet access when connecting via wireless

Run this in the terminal:

[[ $(ping -c4 google.com) ]] 2>~/ping_check.txt && echo "I have Internet" || echo "I don't have Internet"

For example:

$ [[ $(ping -c4 google.com) ]] 2>~/ping_check.txt && echo "I have Internet" || echo "I don't have Internet"
I have Internet

This uses the basic ping utility to send ICMP ECHO_REQUEST packets to the remote host and get the ECHO_REPLY from the remote host (google.com in this case). If the host is UP (& if the firewall at both end allowing ICMP), you will get response back from the remote host, otherwise not.

This one-liner has an added advantage, the error message (STDERR) will be saved in a file in your homw directory ~/ping_check.txt. If you don't have internet then you can check the file content and get an idea of the cause.

EDIT: Explanation of the command:

The command has three portions:

[[ $(ping -c4 google.com) ]] 2>~/ping_check.txt will ping "google.com" 4 times and 2>~/ping_check.txt will save any error message from the command in the file ~/ping_check.txt so that you can check it later for potential problem. As we are only concerned about the success or failure of the command ping -c4 google.com we have put it inside the bash keyword [[]] so that it will return true $? = 0 if the command succeeded or false $? != 0 if the command failed.
Then we have fairly simple command echo "I have Internet" which will just print I have Internet only if the previous returns success, this is ensured by &&. && indicates that the next command will run only if the previous command (ping) is successful.
the next part has echo "I don't have Internet" after ||. || means the next command will be run only if the previous command is successful ($? != 0). So I don't have Internet will be printed only if the ping command returns failure.


How to install snap packages behind web proxy on Ubuntu 16.04

A system option was added in snap 2.28 to specify the proxy server.

$ sudo snap set system proxy.http="http://<proxy_addr>:<proxy_port>"
$ sudo snap set system proxy.https="http://<proxy_addr>:<proxy_port>"

Documentation


Graphical terminal misinterpreting input

Have modified your bash prompt, PS1? what is its current value set to? If you have bytes that don't add to the length of the prompt, such as terminal escape sequences, and fail to enclose them in \[ \], bash will think the prompt is longer than it is, and lines will wrap around incorrectly. See http://mywiki.wooledge.org/BashFAQ/053


It's not very clear what you are asking but in case you want curl to follow redirects, you can do the following:

Tell curl to follow redirects:

In curl's tradition of only doing the basics unless you tell it differently, it does not follow HTTP redirects by default. Use the -L, --location to tell it to do that.

When following redirects is enabled, curl will follow up to 50 redirects by default. There's a maximum limit mostly to avoid the risk of getting caught in endless loops. If 50 is not sufficient for you, you can change the maximum number of redirects to follow with the --max-redirs option.

Syntax:

curl -L <URL> | grep "<your-search-term>"

So, you should use:

curl -L https://eshop.unihobby.cz/zahrada-zimni-sortiment-vanoce-vanocni-osvetleni-interierove-osvetleni-vanocni-led-osvetleni-100ks-8-programu-barevna-bila-vnitrni/142117p/ | grep "Litujeme, ale stránka nebyla nalezena"


E: Package 'openswan' has no installation candidate

You can fork the repo directly from Git repository. Then cd into your forked repo

git clone https://github.com/xelerance/Openswan.git fordername

To use Openswan with the linux native (builtin) IPsec stack, make programs:

sudo make install

To use the Openswan KLIPS IPsec stack (ipsec0 devices) for Linux
Kernels 2.6.23 and higher, make programs

make KERNELSRC=/lib/modules/`uname -r`/build module
sudo make KERNELSRC=/lib/modules/`uname -r`/build install minstall