How do I fix Unity crashing after using Unity Tweak Tool to set Window spreading/scaling?

I was able to work around and fix this problem.  I've seen the same problem as well on Ubuntu 14.04. It seems to be caused by how Unity Tweak Tool handles configuring "Window spreading." (I suspect that it doesn't eliminate a conflict between scale and something in Desktop Wall plugin).  Scale in compiz will do "Window Spreading" without crashing if you enable it there in CCSM (CompizConfig Settings Manager) rather than using Unity Tweak Tool to do it.

First, what you can do without resetting everything right after the crash (some right-clicking and double-clicking still works on desktop in the cases I have seen) is to right-click on desktop, and create a new text file. Right-click on the icon and make it executable using the Properties you can get by right-clicking on the icon and going to the Permissions tab, and put a check in the 'Allow executing file as program' checkbox. (If you cannot do even these you might be able to Ctrl-Alt-F1 to console, logon, and issue sudo killall Xorg or issue sudo service lightdm restart, and you should be dropped back at the greeter to log back on and start over--or you can Ctrl-Alt-F7, if not).

Next, double-click the icon you created and click Display to open the file with the default text editor.  Put in the file as follows:

unity --replace

Now save the file.

Then, double-click the file you created, click the Run button in the dialog that should come up, and Unity should be back up and running in a few moments.  Any time Unity crashes you can double-click that icon to bring it back up while you do the following to work around the issue.

Finally, open up CCSM (Compiz) and Unity Tweak Tool.  Turn off Window spread and close Unity Tweak Tool. Go over to Scale plugin in CCSM, and enable it. As soon as you do that, you will get a notice about a conflict between that plugin and something in Desktop Wall (or another plugin, depending upon where the plugin conflict actually is on your machine. Choose to resolve the conflict and choose to disable the conflicting compiz plugin. Then you can go to the Bindings tab and set your hot corner for (screen icon) Initiate Window Picker (Super-w may already be set, but if not you can set it).  Close CCSM.  Trash the icon you created on the desktop, when done.

After doing this I no longer am seeing the crash, no matter how many times I use the Window Spreading/Scale effect, even while writing this (had to try it a few times just to see if I could make it crash while I was writing this--yeah, living on the edge).

The issue isn't in Unity but rather in how Unity Tweak Tool fails to resolve a Compiz plugin conflict when setting Window Spreading. It sets things for the Scale effect but doesn't handle the conflict and disable it.  Someone probably should let the developer of Unity Tweak Tool know about that issue.

Hope this helps those experiencing this same crash.


i dual booted 64 bit ubuntu 14.04 with windows 8.1 on laptop with 4 gb ram..it now shows 2gb in either operating system

This actually looks like a stick of ram has vanished!

When either Linux or Windows is running on bare hardware, they will see all of the hardware of the system, did you open your system in order to install a new HDD for the ubuntu install?

Windows and Linux will both probably be seeing the same stick of ram, please update your post with infomation on anything which you may benefit us to help you, including the answers of the other question.


Linux command-chkTran working in putty is not working in Java code

In scripts, always provide the full path to executables. If the executable is present in the current directory you can do ./chkTran S6543FL121498, where . denotes the current directory. Otherwise, do
/usr/local/data/sales/workopen/chkTran S6543FL121498

without the need to cd to the directory first.


How to digitally sign documents in OpenOffice under Ubuntu?

To date, I have not found any solution for digitally signing under OpenOffice or LibreOffice. It's really too bad as these open source products are great, but there is zero support for this issue.
I am using a commercial product (Master PDF 5), which is available free but watermarks pdfs. I'm not thrilled but for now it does the job.


How do I remove a specific line and lines just before and after it?

Ok, something ugly, but working:

pattern="apt-get\ upgrade"
prog="BEGIN {b=0} /$pattern/ {print; b=1; next} {if (b==1) {b=0;next;} else {print;}}"
cat test | awk "$prog" | tac | awk "$prog" |tac | grep -v "$pattern"

Second line create a awk program that remove the line following the one where the pattern is found.

Then this program is run on the test file, the output is reversed, the program run again, output is reversed, and line with pattern are removed.

Something shorter, with the same approach:

cat test | sed -e "/$pattern/{n;d}" | tac | sed -e "/$pattern/,+1d" |tac

I believe that reversing the file is mandatory, because to my knowledge, stream-processing tools cant go backward.


Printing and PDF-export from LibreOffice: SVG images get rasterized in very bad resolution

It's a bug. The solution is to either export SVG to EPS first (then the vector graphics will be kept, and not rasterized), or convert to a high resolution PNG before embedding in LibreOffice. See also comment #16 in the above thread.


How do I check the status of the CMOS battery?

$ cat /proc/driver/rtc | grep batt
batt_status     : okay


What you can do with your two 4GB USB pendrives

I think the best thing you can do with your current USB drives is the following.

Boot from the drive with Lubuntu 17.10.1 (which is live-only)
Install mkusb,

sudo add-apt-repository universe  # only for standard Ubuntu

sudo add-apt-repository ppa:mkusb/ppa  # and press Enter
sudo apt-get update
sudo apt-get install mkusb mkusb-nox usb-pack-efi

This works but will not be persistent.
Make the lubuntu-17.10.1-desktop-amd64.iso file available to the live-only system (by connecting a drive with the file and copying or downloading the file again).
Use mkusb to create a persistent live Lubuntu system in the second 4 GB USB pendrive. See this link: help.ubuntu.com/community/mkusb/persistent

Select 100% for persistence (which may cause complaints, but it should work anyway).
Shutdown and remove the first (live-only) USB drive.
Boot into the second and now persistent live USB pendrive. You can stop here.
If you want more drive space for persistence, you can connect the first (live-only) USB drive.
Use gparted to

remove the partitions on the first (live-only) USB drive,
create a partition with an ext4 file system
and put the label home-rw on that partition.
If problems with gparted, install mkusb in this persistent live system and use it to wipe the first mibibyte. After that gparted should work (Select 'device' and create a partition table and after that a partition ...)

Reboot into the persistent live USB drive and select Try Lubuntu (not with  persistence).

Connect the home-rw USB drive.
copy the content of /home to the home partition, dry run to check,

 sudo rsync -Havn /media/lubuntu/casper-rw/upper/home/ /media/lubuntu/home-rw

and the real copying (without the option n)

 sudo rsync -Hav /media/lubuntu/casper-rw/upper/home/ /media/lubuntu/home-rw

Reboot with both USB pendrives connected.

If you cannot select the correct USB drive for booting, the one with the operating system, you can boot and when at the grub menu connect the other USB drive (with home-rw). Then continue from the grub menu.
Now you should have a persistent live system with a maximum 3 GB casper-rw partition for the root file system (to install programs etc) and a 4 GB home-rw partition for /home, and you can use a total of 7 GB for persistence.
When you have confirmed, that your system is persistent, and that it uses both casper-rw and home-rw, you can remove /media/lubuntu/casper-rw/upper/home/.

Check that it looks like this:

You can right-click on the screenshot and open it in a big window to see it in full size.

Command lines and output from them:

lubuntu@lubuntu:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            1.9G     0  1.9G   0% /dev
tmpfs           384M  6.1M  377M   2% /run
/dev/sdc4       925M  925M     0 100% /cdrom
/dev/loop0      863M  863M     0 100% /rofs
/cow            2.6G  137M  2.3G   6% /
/dev/sdb1       3.7G  8.0M  3.4G   1% /home
tmpfs           1.9G     0  1.9G   0% /dev/shm
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           1.9G     0  1.9G   0% /sys/fs/cgroup
tmpfs           1.9G  4.0K  1.9G   1% /tmp
tmpfs           384M  8.0K  384M   1% /run/user/999
/dev/sdc5       2.6G  137M  2.3G   6% /media/lubuntu/casper-rw
lubuntu@lubuntu:~$ sudo parted /dev/sdb p
Model: SanDisk Cruzer Blade (scsi)
Disk /dev/sdb: 4005MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number  Start   End     Size    Type     File system  Flags
 1      1049kB  4005MB  4003MB  primary  ext4

lubuntu@lubuntu:~$ sudo parted /dev/sdc p
Model: JetFlash Transcend 4GB (scsi)
Disk /dev/sdc: 4052MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:

Number  Start   End     Size    File system  Name     Flags
 2      1049kB  2097kB  1049kB               primary  bios_grub
 3      2097kB  258MB   256MB   fat32        primary  boot, esp
 4      258MB   1247MB  989MB                primary
 5      1247MB  4051MB  2804MB  ext2         primary
 1      4051MB  4052MB  681kB                primary  msftdata

lubuntu@lubuntu:~$ sudo lsblk -f
NAME   FSTYPE   LABEL               UUID                                 MOUNTPOINT
loop0  squashfs                                                          /rofs
sda
├─sda1 vfat                         AD68-7CA2
├─sda2 ext4     lubuntu             0162276e-c99e-43b5-87c3-59bb064af44b
├─sda3 swap                         b66eb718-af47-41d0-9932-e35cdaae11c3 [SWAP]
└─sda4 ext4     xubuntu-core        ad262cdc-ba80-4536-b686-1caf1b5ef441
sdb
└─sdb1 ext4     home-rw             d43d50f7-f372-47da-9f22-eb075e725164 /home
sdc
├─sdc1
├─sdc2
├─sdc3 vfat     usbboot             BF5D-50BE
├─sdc4 iso9660  Lubuntu 17.10 amd64 2018-01-06-00-29-08-00               /cdrom
└─sdc5 ext4     casper-rw           03f25a82-d74b-497e-b86e-a6efaf749d6f /media/lubuntu/casper-rw
sr0
zram0                                                                    [SWAP]
zram1                                                                    [SWAP]
zram2                                                                    [SWAP]
zram3                                                                    [SWAP]
lubuntu@lubuntu:~$ sudo lsblk -m
NAME     SIZE OWNER GROUP MODE
loop0    863M root  disk  brw-rw----
sda    111.8G root  disk  brw-rw----
├─sda1   512M root  disk  brw-rw----
├─sda2    15G root  disk  brw-rw----
├─sda3   3.9G root  disk  brw-rw----
└─sda4    15G root  disk  brw-rw----
sdb      3.7G root  disk  brw-rw----
└─sdb1   3.7G root  disk  brw-rw----
sdc      3.8G root  disk  brw-rw----
├─sdc1   665K root  disk  brw-rw----
├─sdc2     1M root  disk  brw-rw----
├─sdc3   244M root  disk  brw-rw----
├─sdc4   943M root  disk  brw-rw----
└─sdc5   2.6G root  disk  brw-rw----
sr0     1024M root  cdrom brw-rw----
zram0  478.9M root  disk  brw-rw----
zram1  478.9M root  disk  brw-rw----
zram2  478.9M root  disk  brw-rw----
zram3  478.9M root  disk  brw-rw----
lubuntu@lubuntu:~$

More powerful alternative

Things will work better (and be easier), if you get a fast USB 3 pendrive with at least 16 GB, and create a persistent live Lubuntu system in that drive.


12.04 started in low graphics mode, couldn't fix

I am not sure if this will help,

type, cvt 1440 900 (This can be your actual resolution your card and monitor call for like 1908 1024)

in the modeline you need this part for what we are about to do - 173.00  1920 2048 2248 2576  1080 1083 1088 1120

next we need to add your graphics mode type this  - xrandr --newmode clever_name 173.00  1920 2048 2248 2576  1080 1083 1088 1120 - (clever_name being like your vid card or something meaning ful to you

Now we need to add your mode - xrandr --addmode VGA1 clever_name

Set your Monitor to use it: xrandr --output VGA1 --mode clever_name

I hope this helps .... Let me know.


How to make files download/store to another disk

mount the new raid array to the folder where the data is downloaded to.

first copy any data there to the new drives; data left in the folder will be unseen when the drive is mounted to it, thus should be empty.

mount /dev/md0 /where/the/folder/is

will mount it

edit /etc/fstab for auto-mount at boot:
add/change line to read

UUID=<id of raid>   /where/the/folder/is   ext4  default   0   0

you can get the UUID of the raid array by using sudo blkid

this effectively replaces the folder with the drive and all files written to that folder will go the the drive.

NOTE:change device name, file system type, and mount path as is appropriate


Analog and digital audio output at the same time

We have the optional application paprefs  that allows to install a virtual output device to pulseaudio. This enables simultaneous output to all attached sound cards/devices:

The additionally created audio output device for simultaneous output may be selected in the "Output" tab from pulseaudio sound preferences menu:

From the command line we can also load the device for simultaneous output without having to run paprefs by

pacmd load-module module-combine-sink
# pacmd load-module module-combine # for PulseAudio < 1.0

Put this line (without pacmd) in your /etc/pulse/default.pa to load this device at startup.


Can't install acroread - 'dpkg returned an error code (1)'

Seems like you are out of space, to check your hdd just run:

df -h

If this command tells you that the use% is at like 99% or something around that, clean it using this command:

apt-get clean && apt-get autoclean

You may also try to remove unneeded packages from your system using this command:

deborphan | xargs aptitude --purge remove

After you have run these commands, try to install acroread again and you should be fine.


The method is not the best. Please use uname -r to get the results. In my case I get

3.5.0-14-lowlatency

since I'm using Ubuntu Studio.


Ubuntu 12.10 64 bits not booting on a Dell Inspiron 15z Puissance (French) in UEFI mode

Thanks everyone, I have found the solution, I had two problems:

Ubuntu didn't want to boot in EFI mode, except when the firmware was set to Legacy (and let me boot using EFI ¿).
I just clicked "Fix" in all the question screen-shots and then, GPARTED let me change everything I wanted and Ubiquity let me install Ubuntu !

The installation has just finish and I'm going to reboot now.


How to copy symlink files from the ISO Ubuntu installer to a usb stick ( for uefi machine )?

Simply copying and pasting the files (remember to also copy hidden files on the iso) works also on ubuntu. I recently created a bootable USB for my ubuntu 18.04 LTS by simply copying the files from the ISO to a clean fat32 pendrive (MBR partition table). When i booted the pen on UEFI machine it just worked. I was scared using dd was going to damage the drive
 However when I tried that same bootable pendrive to boot in Legacy (BIOS) mode on a different machine it didn't work. In that case i came back to using dd  which worked


Running fsck on internal disk which also has ecryptfs encrypted folder

fsck checks the underlying, physical, blocks-on-disk filesystem. It Must do this when nobody else is accessing the disk (single-user, Live boot). At that time, your encrypted folder is not mounted, therefore not visible, except as blocks-on-disk of binary data with really silly filenames (do a ls of the .Private/ subdirectory to see what I mean). It's only when you have logged in, and mounted your ecryptfs folder that it is decrypted, and can be said to "exist". So in order, the answers to your multiple questions are:

No.

That folder cannot be said to "exist" at fsck time.

Since the encrypted folder is mounted, and appears in /etc/mtab, it will be "handled" when you do a polite shutdown (sudo shutdown, or shut down from the Log out menu. If you just kill power, or halt the VM, you will corrupt your encrypted (and non-encrypted) filesystems, eventually, due to updated disk meta information in RAM not being written to "disk". fsck may then detect (and offer to "fix") problems with the underlying, physical, blocks-on-disk filesystem, which could trash the encrypted filesystem. Do polite shutdowns.

The filesystems you are worrying about have not been created at fsck time.


How to cache pgp passphrase permanently with seahorse (14.04)

To permanently save the a passphrase in the keyring, use seahorse-ssh-askpass from package seahorse:

/usr/lib/seahorse/seahorse-ssh-askpass my_key

Note: You have to have a have the corresponding .pub file in the same directory as the private key (~/.ssh/id_rsa.pub in the example). Also, make sure that the public key is the file name of the private key plus .pub (for example, my_key.pub).


As justingrif suggested did you try removing kvpnc and test?

Also try the below steps:

"Available to all user" uncheck this option.
Advanced settings -> Security and Compression -> check "Use
Point-to-Point encryption(MPPE)" option.


Could not access "synaptics sensors" device error on ubuntu 20.04 focal fosa

I got it working on my Thinkpad X395 by following this: P43s - Working fingerprint reader on Linux : thinkpad
First, uninstall older version of fwupd:
sudo apt-get remove fwupd

Then, install 1.4.1 version of fwupd in Ubunutu Software manager.
Then download firmware and config files from here:

LVFS: Prometheus Fingerprint Reader
LVFS: Prometheus Fingerprint Reader Configuration

Install them with:
fwupdmgr install 3b5102b3430329a10a3636b4a594fc3dd2bfdc09-Synaptics-Prometheus-10.02.3110269.cab
fwupdmgr install cbe7b45a2591e9d149e00cd4bbf0ccbe5bb95da7-Synaptics-Prometheus_Config-0021.cab

The second file was an older version in my case, so you might not need to install it.
Then, try again in Settings→User→Fingerprint Login.


Cairo Dock still visible in Dash, after removal using Software Center

You have not removed the whole package yet. Its data is still in your computer. Remove all by running in the terminal:

   sudo apt-get-purge cairo-dock-core


My server does not forward packets between interfaces. What am I missing?

I've noticed that IP forwarding seems to fail if network manager is managing the interfaces involved in the forwarding. Maybe someone else could explain why?

try adding:

[keyfile]
# interfaces not to manage with Network Manager
unmanaged-devices=mac:00:22:68:1c:59:b1;mac:00:1E:65:30:D1:C4

to your
/etc/NetworkManager/NetworkManager.conf
where you replace the mac addresses above with the ones of your network cards.

or disabling network manager entirely if you don't need it.


Gnome-session broken for specific account, works for other accounts

First, it sounds like you've made some valiant attempts to correct the problem. Kudos.

Perhaps try the command:

dconf reset -f /org/gnome/
dconf reset -f /org/gnome/settings-daemon/
dconf reset -f /org/gnome/desktop/

If those don't work, and you're desperate, you can try this:

dconf reset -f /org/gnome/

And that will reset all GNOME application dconf keys to their defaults.

I can't guarantee that this will work, but it will reset GNOME settings to their defaults.


A more recent answer can be found here: http://robinlovelace.net/r/2013/11/26/installing-rgdal-on-ubuntu.html .

Essentially, the three following lines of code should sort it:

sudo apt-get install aptitude # install aptitude as an alternative to apt-get
sudo aptitude install libgdal-dev # install the package (you may have to respond to queries here)
sudo aptitude install libproj-dev # install the proj.4 projection library

Spent ages on this problem, so hope this updated answer is useful to others. Let me know if so!


Is this WUBI? What is "Installation size" setting for?

As you have established, you have downloaded WUBI.

The "Installation size" options lets you decide the amount of space you want to "give up" for WUBI. That is the space wubi's Ubuntu install is able to use.
Wubi creates a disk image (loopmounted device) on your host system in/on which Ubuntu is installed. This can be compared to a kind of "safe partition" on your system.

This means the space you reserve for Wubi is not usable for your host system any more (in fact it is not even accessible from within the host system without external programmes. Ubuntuforums: Accessing Wubi Disks from Windows , AskUbuntu: How to open wubi's .disk files under windows?). Windows 7 (any Windows for that matter) will count the space you reserve for your Wubi install as occupied since Wubi just creates a file of exactly the amount of space you specified (let's say 20 GB) on your host system's harddisk, regardless of the space actually occupied in your Ubuntu Wubi system.

Apparently, there are ways to resize the wubi virtual disk (Help.Ubuntu: ResizeWubiDisk, Ubuntuforums: HOWTO: Resize the WUBI virtual disk).

You need to reserve enough space for Wubi to install Ubuntu and - if you want to use it properly - to install programmes. Additionally, you will want to have some space for documents etc.

So I'd recommend no less then 8GB of space, maybe even as much as 20GB if you can spare that much.


Take a sreen shot without making a window dissapear when clicking the keys to take the shot

Launch the GNOME screenshot tool from the applications menu and configure a delay to make a screenshot after - say - 10 seconds. Then click the button to do the screenshot (the screenshot tool window will disappear) and start connecting via your VPN. After 10 seconds from your click of the "Screenshot" button the screenshot will be taken automatically, the screenshot tool window will re-appear and you can save your screenshot.


In a terminal, you can do a

dpkg --list

to get an overview of all installed packages including their version numbers. Since this generates usually a long output, you might consider to do

dpkg --list | less

or

dpkg --list | grep qt


If all fails, there is another option that will work almost for sure if the drive is not broken:

At least one of your partitions (not the data partition) needs to be large enough to contain the system (6GB).
If that is the case, start the installer ("Install Ubuntu") and walk through the steps until the window: "installation type". Choose "something else".

In the partition overview (in the next window), select the partition you need to save the data from, and choose "change" (next to the +/-). Choose the same filesystem as the partition already is, set the mount point to /rescue or something.

Assign the swap partition (it is already there) and do not reformat /rescue. Set the mountpoint of one of the other partionos to / and install Ubuntu. After installation is finished, the files will be in /rescue.

If you do not have a "spare" partition, you would have to resize the data partition first to be able to create a partition that can hold the system.


My personal favourite is gthumb image viewer. You should search for it in the Ubuntu Software Centre and give it a try to see if it suits your needs.


Cannot boot into Windows 7 after installing 12.04

Open a terminal, update the grub by command :
sudo update-grub
Reboot the computer and go into BIOS setting (mostly is the delete button)
choose the hard-disk as primary boot device
Save the setting and exit
The computer will be booted again, and you will find the booting manager comes out


juju illegal base64 data at input byte 9

I solved by doing a sudo apt-get install dbus under my bootstrap environment.


How to prevent my drive with Windows partition from unmounting undesirably?

This answer doesn't directly address the main point of the question, but rather, a question in a comment; specifically:

  Can you please explain to me what you mean by a "separated NFTS data paratition" ? Nothing on my SSD is Ubuntu and nothing on my HDD is Windows. Are you suggesting that I install Ubuntu on the SSD (just on a separate partition)? Is it not safer to have the two OS's on different physical drives? A friend recently wiped out her entire Windows partition from Ubuntu somehow.

Some users like to isolate two OSes in a dual-boot environment, as you've done, each to its own hard disk. The idea is that by doing so, one OS is less likely to cause damage to the other; however, in your case, you're accessing the main Windows installation (the C: drive in Windows) from Ubuntu. This means that Ubuntu can modify that disk; indeed, the very act of mounting the Windows disk modifies it (in a small way). This access isn't just access to the files themselves, but to the data structures that define what the files are. This is particularly problematic for NTFS, because that's a proprietary filesystem for which a public specification does not exist, AFAIK; the Linux drivers are based on reverse engineering. In practice, the Linux drivers work pretty well, but there's always a chance that they're doing something subtly wrong, which could trash the entire filesystem.

There's also the fact that Linux and Windows have very different security models. Thus, files that Windows protects from damage via its security system are freely available to ordinary users in Ubuntu; you can easily, and even accidentally, delete critical drivers, configuration files, etc., from Ubuntu.

Thus, putting the OS installations on separate physical disks does very little to protect them from one another unless you physically swap disks in order to boot each OS -- and that poses its own risks. (A static charge could fry a disk when you swap them out, for instance.) Physically swapping disks will also make it impossible to share data between OSes, except via a third disk, network share, etc. Where putting the OSes on separate disks might help (a little) is in the initial setup; you're less likely to accidentally wipe OS A when installing OS B if each one has its own disk and you therefore don't need to resize OS A's partitions.

If you don't need to share access to the same files, you can restrict each OS's access to the others' files, no matter where each OS is installed. Restricting Windows' access to Ubuntu is easy; Windows lacks support for Linux filesystems, so Windows won't access Ubuntu partitions unless you explicitly install Linux filesystem drivers in Windows. (An exception is if you set the wrong partition type codes, as was once common on GPT disks; but that's unlikely with any modern installation. See this page of mine if you think you might be running into this problem.) To restrict Ubuntu's access to Windows, I recommend creating an /etc/fstab entry for the Windows C: partition that does not automatically mount it, or that mounts it read-only at most. See here for more on how to do this.

If you want to share data between OSes, then, it's best to create a separate partition for that purpose. This will enable you to read and write to that partition from both OSes without endangering the main OSes' files. You can either create a separate /etc/fstab entry for each partition (the Windows C: partition and the shared-data partition) or rely on auto-mounting to access the shared-data partition.

In your two-disk setup, it doesn't matter, from a logical perspective, which disk holds the shared-data partition. You should make that decision based on available space and disk speed. How much data you put on the shared-data partition is also an open question. It might be a small partition in which you store just a handful of files; or you might choose to put most of your user data on the shared partition.

A big caveat to this is that converting from your existing setup to one with a shared data partition will require resizing at least one other partition. You might also end up wanting or needing to move at least one other partition. These operations can be time-consuming and carry some risk. Thus, if you can fix the main problem of your question, you might prefer to just leave your partition layout as-is for a while and keep this in mind for your next installation. OTOH, if you want to rearrange your system in a major way, this can be another reason to do so sooner rather than later.


I'm not sure what the issue was, but resetting my VLC preferences (per the advice at http://www.videolan.org/support/faq.html) fixed things.


make sure to restart your web server. if you are using apache you can restart it like so:

sudo /etc/init.d/apache2 restart


Problems installing Ubuntu alongside Windows 7

I experienced the same installation crash with the same error message.  Apparently either the the copy of the installation ISO that I downloaded or the copy created in the USB memory stick was defective.  I downloaded a fresh copy of Ubuntu 14.04, formated the memory stick and installed the new copy.  Then in the installation process, I checked the disk for errors and found none.  This time the installation proceeded to completion without problem.


Vlc - package dependencies cannot be resolved

VLC is there in the Ubuntu Repos as well. You can install it after enabling universe Repo. This should be automatically enabled for you when you Install Ubuntu and select install 3rd party software and install Updates while Installing.

If you missed it during Install you can enble unniverse repository by Opening Software and Sources and select the repositories as shown in the picture.

After hiting close you get option to reload the Cache.

Once that is done you should see VLC in software Center or you may install it via command line.

There is no need for adding any third party repo unless you can't find what you want in the official repo or you want the latest and greatest.

PPA's can sometimes break your system because of library mismatch. Alway USE PPA's with caution.


Problem in boot up(14.04); asking passphrase

The Ubuntu installation wizard offers to setup a disk encryption (besides the protection of you user and admin/root accounts). It might be even activated by default (so that it would have have been necessary to deactivated it explicitly in order to avoid it at installation). During the installation you have been certainly asked to enter a password besides your user password.

Maybe you entered your user password?


How to rename a file which seemingly has no name

In your case, the filename is ". As " is special to the shell, you need to escape it using any of the usual escaping manners.

You can do any one of the following, from the directory containing the file:

mv \" new_name
mv '"' new_name

Replace new_name with the actual name you want.


This could be caused by a cache corruption. We should file a bug with duplicity to clean up the error message, but in the meantime, clear the cache:

rm -r ~/.cache/duplicity


Wireless slow on an Intel AGN5100 on an hp Presario C45

First method : You need to disactivate IPv6, to do that, open terminal and enter the following commands:

echo "#disable ipv6" | sudo tee -a /etc/sysctl.conf
echo "net.ipv6.conf.all.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf
echo "net.ipv6.conf.default.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf
echo "net.ipv6.conf.lo.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf

Then restart your system. If you still have the issue, follow also instructions on step 2.
Second method:  A second solution for this issue can be by using the following :

Open terminal and enter the following command:

sudo -s
gksu gedit /etc/modprobe.d/ath9k.conf

That will open a gedit config file. At the end of the file add this:

options ath9k nohwcrypt=1

Save an restart your OS.

(source: http://www.unixmen.com/linux-tutorials/linux-distributions/linux-distributions4-ubuntu/1785-resolve-slow-connexion-when-using-wifi-in-ubuntu-1104-natty-narwhal)


Google Chrome unity icon does not restore after minimizing

Works fine here - the launcher icon for goggle-chrome launches & controls google-chrome plus the 2 quicklists options.

Maybe try resetting - Remove the icon from the launcher if pinned, then do a log out/in.

While you shouldn't need to,  try adding back to launcher this way - Browse in nautilus to /opt/google/chrome. Inside you'll see 'goggle-chrome.desktop'. Grab it with your cursor and DnD onto the unity launcher, then see if it works as intended.

This fixed the issue for me with  64 bit Ubuntu 12.04:  simply launching "chrome" from the dash didn't work, I had to use the nautilus method described above.


how can I fix the (broken) icons in the notification area upon login?

Try

killall gnome-panel

The panel will disappear, but don't panic... it will reappear in a few seconds with all your icons in place.


You could try the Lubuntu distribution. It's not as pretty as Ubuntu but light on resources and very responsive.

You can even switch to it without a total system re-installation while retaining the Unity desktop in case you want to go back.


How to set up DNS in 16.04 whithout using network-manager

If you remove Network Manager, then, in 16.04, the usual way to configure networking is in the file /etc/network/interfaces. You file will look approximately like:

auto lo
inet lo iface loopback

auto enp3s0
inet enp3s0 inet static
address 192.168.1.150
netmask 255.255.255.0
gateway 192.168.1.1
dns-nameservers 144.114.114.114

Of course, substitute your exact details here.

If you prefer DHCP, then:

auto lo
inet lo iface loopback

auto enp3s0
inet enp3s0 inet dhcp
dns-nameservers 144.114.114.114

Reboot.

EDIT: It appears that you may have an issue with resolvconf. Please run:

sudo dpkg-reconfigure resolvconf

Use the TAB key to accept the offer to reconfigure. Reboot.

Any improvement?


I finally found a solution to this problem. As I said, the problem seems to be that the installer can't correctly recognize the startup partition and install grub correctly since there are 4 separate partitions used by Windows and by the one key recovery system installed by Lenovo (correct me if I'm wrong, I'm just assuming). Since Lenovo doesn't provide the Windows disc, but only recovery discs to reset to factory default, the only way to make the dual boot work is to "fix" the installation of grub (this is quite annoying since you will always be stuck with bloatware). Luckily, there is a way to do this, explained in this tutorial. I believe there are other people out there having this same problem with Lenovo laptops. I hope this helps.


Don't know if this is relevant, but the following page has a lower-case "y" in the "yes"

http://wiki.debian.org/bootlogd


Is there an alternative to gnome-terminal?

Feel free to edit in info on features and/or maintenance.
There is a blog post at OMG! Ubuntu! that lists five alternatives to gnome-terminal. Another post at Tech Drive-in adds even more other ones. For screenshots, see these websites.
Terminator
"It allows you to split its main window into as many tiles anyone could ever need."
sudo apt-get install terminator

Here are some of its features:

Arrange terminals in a grid
Tabs
Drag and drop to re-order terminals
Lots of keyboard shortcuts
Save multiple layouts and profiles via GUI preferences editor
Simultaneous typing to arbitrary groups of terminals

Tilda
"a configurable “Quake-style” terminal emulator, meaning that it slides down from the top of your desktop when a user-configurable key (default is F1)" No longer actively maintained?
sudo apt-get install tilda

As said at linuxlibrary: "Tilda does seem to offer more customization options than similar drop-down style terminals":

Highly customizable interface.
Set the level of transparency for the main Tilda window.
Unique built-in color schemes.
Users are able to reduce the main window to its most minimal state.

Guake
"similar in functionality to Tilda"
sudo apt-get install guake

Stjerm
"comparable to [...] Guake and Tilda. It’s also very lightweight, features tabs, and an option to toggle fullscreen"
sudo apt-get install stjerm

Yakuake
"KDE-native"
sudo apt-get install yakuake

CLI companion
mostly to learn terminal commands
sudo add-apt-repository ppa:clicompanion-devs/clicompanion-nightlies

sudo apt-get update

sudo apt-get install clicompanion

or download a .deb file for it from here.

Eterm
"Eterm is the lightest of them all"
sudo apt-get install eterm

ROXTerm
"Supports features like drag & drop of items into Terminal windows"
sudo apt-get install roxterm

Aterm:
"Extra features include fast pseudo-transparency, optional off-focus fading of text"
sudo apt-get install aterm

Wterm
"An extensive set or runtime options are available resulting in a very customizable terminal emulator" No longer actively maintained?

TermKit
"a command line based system made on top of WebKit"

Terminology
As rajagenupula mentions there is also terminology.
It "can do a lot of things you wouldn't expect from a terminal emulator, like displaying thumbnails for images, videos and documents and furthermore, it also allows you to preview those files directly from Terminology" (quote from webupd8)


How to clean up a broken `snap try` snap after reboot?

The easiest way I've found to clean up this snap is to run snap try on the same directory again. This causes snapd to perform the mount operation again and puts the snap in a reasonable state from which you can continue testing or remove the snap cleanly.


As long as you don't mind applying the changes to all of your mice (or only have one) I'd suggest removing the two MATCH lines and replace them with:

MATCHISPOINTER 'true'

Be sure that the name of the file you create in that directory ends in .conf. I've forgotten that several times.

Alternatively

xinput list

will list the names by which the xserver knows all devices. This particular information is from ManuelSchneid3r at https://unix.stackexchange.com/a/72732.


zswap: compressor lz4 not available, using default lzo

I think for some reason the module should be loaded before generating the initramfs.

Try the following, worked for me on Ubuntu 16.04.

sudo modprobe -v lz4
sudo update-initramfs -u
sudo reboot


Ubuntu Desktop shortcut icons not working

I found one solution to make shortcut icons to work again.
Simply install snapd if not installed:

sudo apt install snapd

Then disable and enable again applications with not responding shortcut icons:

sudo snap disable <appName>
sudo snap enable <appName>

For example:

sudo snap disable postman
sudo snap enable postman

Here some explanations that could be useful for some guys (that like me are not very in deep with Ubuntu) having other but similar problems:

I noticed all of not working icons are for applications that are located in /snap directory. (snap is an application that like apt or apt-get install packages on Ubuntu - see comparison of them). I have never used snapd before but obviously Ubuntu Software application that I use for install\uninstall applications used it. So I needed to install first the snapd and then I just executed its commands disable and enable for the problematic application (Postman, Notepadqq and Opera browser in my case).


Try reconfiguring the jackd2 package:

sudo dpkg-reconfigure jackd2

And answer 'Yes' to the question if you want to enable realtime priority. After that add yourself to the 'audio' group:

sudo usermod -a -G audio yourusername

And try again.

Regards,

Jeremy


Partition issue on upgrade to Ubuntu 17.04 from 16.10

if  under stand correctly, you are copying from a 750 GB to a 250 GB?

when you copy the MBR it copies the reported size in the MBR.

he's what I'd do since you have a second working Ubuntu.

1) reformat the drive so you get the right space indication, and make your partition. (you might need to do this on windows so the MBR gets wiped)

2) copy your partition with clonezilla. boot into your working ubuntu, then connect the new drive. Use gparted to change uuid, and edit /etc/fstab of the copy to reflect the change.

3) update grub to get a grub entry for the new ubuntu. boot into the new ubuntu using the grub of the old ubuntu

4) once in the new, update initramfs, then install and update grub.


How to set Quodlibet as default music player?

To make any music player that comes with sound indicator integration the default player in there we may from 13.04 install and run unity-tweak-tool . Open the "Panel" settings and choose any of installed players:

The example above will then make Guayadeque the default player in the sound indicator:

Of course if we prefer not to install an additional application, or if a player such as Quod Libet does not come with full indicator sound integration we can also do this with dconf-editor (from dconf-tools  in Ubuntu < 13.04):

Quod Libet need the MPRIS plugin (quodlibet-plugins ) for full player control.


Simply placing the .iso on the USB drive is not enough. If you intend on booting from USB you will need to do two things - you will need to change your BIOS settings to allow booting from USB and you will need to make the drive bootable. If you have another computer available I suggest using UNetBootin to create a bootable USB drive with your preferred flavor of Linux


How do I get back plain Unicode characters in Ubuntu 18.04?

Installing the Symbola font does the trick:

sudo aptitude install fonts-symbola

This seems to be the font I used on 16.04 but it's of course hard to be sure.


Have to run the "sodu dhclient eth1" after reboot

Try WiCd instead: See http://wicd.sourceforge.net - Recommending because I've had much better experience with it than the standard network manager.


Since it launches properly from the terminal, you can

Option 1) simply create a new shortcut for it as described here. or

Option 2) repair the existing shortcut at usr/share/applications/unity-control-center.desktop which on my system looks like this:

[Desktop Entry]
Name=System Settings
Icon=preferences-system
Exec=unity-control-center --overview
Terminal=false
Type=Application
StartupNotify=true
Categories=GNOME;GTK;System;
OnlyShowIn=Unity;
Keywords=Preferences;Settings;
X-Ubuntu-Gettext-Domain=unity-control-center

Option 3) reinstall the package with:
sudo apt-get --reinstall install unity-control-center

Any of these approaches should work.


I uninstalled mythtv-dbg for the same reason, and everything seems to be fine.


How can I resize pictures changing the aspect ratio?

As per Adonis' comment, the exclamation mark, ! forces mogrify to ignore the aspect ratio of the original image. so using 1920x1080! in the size parameter did the trick.


Ubuntu 64 bit 16.04 LTS keeps freezing on laptop Hp Pavilion X2

Are you sure it isn't a hardware problem? Your syslogs aren't turning up any errors(did you check them all?), that makes me think it might not be a OS problem.

You can check your memory with memtest86, https://help.ubuntu.com/16.04/ubuntu-help/disk-check.html for your hard drive.(or use UBCD or something like it to test your system).

You could test to see if the problem occurs in windows. it will at least help you exclude some things.


Can I assign custom keyboard shortcuts for menu items in applications?

There is an obscure setting that is for this. XFCE has it in the GUI, but Gnome/Unity does not. The feature is an obscure one that's turned off by default, and perhaps because so few people use it, it doesn't always work very well.

But give it a try anyway. You'll need to install gconf-editor, if you haven't already:

sudo apt-get install gconf-editor

If you go into gconf-editor and do a search (ctrl+f) for "can_change_accels". In the dialog, make sure and check the "Search also in key names" checkbox. You should see a result with something like /desktop/gnome/interface/can_change_accels.

Check that to True.

Once that's enabled, you can configure shortcuts by clicking on a menu and hovering your mouse over an item. When the menu item you want to bind a shortcut key to is hovered over, type the shortcut. It should appear immediately.

There are some caveats. One is, I'm not sure this works with Unity's global menu bar. Since I don't use Unity, I can't test and make sure. Another caveat is that non-native Gnome apps probably won't do this. So for example, if you're running a Java app, don't expect this to work.


Is there an application to create windows with messages?

The application you're looking for is called zenity. Here's your hello world:

zenity --info --text="Hello World"

Documentation
Man page


Ubuntu 18.10 how to rename current terminal Tab title

This is a long standing bug that appears to have been 1st reported around 2016.

A currently viable workaround is to install mate-terminal which still has the ability to set the title of the terminal screen as reported by Erik B. Andersen in this bug report comment.

I have tested this workaround under Ubuntu 16.04 as well as 18.04 and can testify that it does indeed work as advertised.

The downside is that it requires the installation of other Mate related supporting packages.


software installation of a file having .rpm extention

I had a similar problem with Substance Designer, I ended up adding the --scripts argument to the alien statement and the resulting deb package ran without a hitch. The full command would be something like...

sudo alien --scripts -d PackageNameHere.rpm

The logs from DPKG may also hold some clues. If that doesn't work, you could try having Alien install it by adding a -i to the command.


Deleting these directories helped me -
cd ~/.local/share/plasma
sudo rm -rf look-and-feel/
sudo rm -rf desktoptheme/


For your cursor issue:
Delete the package breeze-cursor-theme and it's dependencies with this command:

sudo apt purge breeze-cursor-theme --autoremove

To change the boot logo, run this command:

sudo update-alternatives --config default.plymouth

You should see a list with available logo options. Chose the one you want.

After that you can delete the kubuntu "boot logo" package with this command:

sudo apt purge plymouth-theme-kubuntu-logo --autoremove

Just a tip: With this command, you can list KDE related packages:

dpkg -l | grep -i KDE

(But be careful with deleting them.)


Unable to locate package libc6-i386 and lib32z1

This two packages are only available for the amd64 based systems ("normal" 64 bit PCs) but not for armhf like the Raspberry PI 3.

If Pulse Secure requires them it's most likely only available for amd64 and doesn't work on a Raspberry PI.


EFI partition and boot manager - dual boot windows 8 and ubuntu

If you've tried using bcdedit in Windows, as described in the Windows 8 removes Grub as default boot manager question you cited, and if that doesn't work, then it won't work any better with Ubuntu 14.04 than with 13.04. Basically, what you're looking at now is a buggy firmware. You might check with HP to see if they've fixed that bug in a firmware update. (They probably call it a "BIOS," but really it isn't a BIOS; it's an EFI.)

If HP has no updated firmware, then given that your computer is too old to be returned to the store for a refund, your only choice is to find a workaround. One that's likely to work is to rename EFI/Microsoft/Boot/bootmgfw.efi to something else and rename your chosen boot manager to use that name. You can use the Advanced options tag in Boot Repair to do this automatically, or you can do it manually. Alternatively, if you switch to rEFInd as boot manager, you can use its mvrefind.sh script to do the job, as described here. Note that such a renaming operation is a very hackish workaround to a bug that should never have seen the light of day. The "fix" can in fact cause further problems down the line, or it might be undone by Windows if it notices that its boot loader has been overwritten. I strongly recommend you back up your ESP if you do this, so that you can restore it to a known-working state if something bad happens down the line. A file-level backup (using tar, cp, or whatnot) should be adequate.


You can press Ctrl+Alt+F1 to get to console, where you can kill any process.

If that does not work either, you can reboot by Ctrl+Alt+S,U,B.


I think there are many things you could do better in your configuration, such as using either UUID or disk labels instead of the /dev/sdxx notation (since that can change).

But the main problem seems to be that you are specifying /newhd/shareddocs in the problem command, but the actual mount point is /media/newhd/shareddocs.

EDIT1

If you want to mount a subdirectory of the partition /dev/sdb1, then you would need to first mount the partition, and then mount the directory within that partition, I think.  I normally just use sharing, but I believe you would do it this way if using fstab:

/dev/sdb1 /media/NEWHD ext4
/media/NEWHD/shareddocs /home/foc

Or, if you don't want to edit fstab, you can use mount without --bind
sudo mount /newhd/shareddocs /home/foc

EDIT2
Personally, I have no experience with the bind option - I normally just use symbolic links, which work fine for what I have needed.  Not there are good reasons for using bind, and it is a good way to mirror a directory structure without creating a special file that may not work in all situations.

So, there are a couple of tricks that might help, although I think the solution is simply to add "bind" as an option in /etc/fstab.

There is another file similar to fstab in the same directory, named /etc/mtab; this file shows all the current mounts, whether done via the mount command or via the fstab file.  So, you can look at this file (cat /etc/mtab, or use gedit), and copy the line that is working into /etc/fstab.  I believe you will find that the line is /media/NEWHD/SharedDOCS /home/foc none rw,bind 0 0.

The other trick is useful whenever you are making changes to /etc/fstab. After you make a change, save the changed file but don't close it yet.  Then, go to the terminal and enter sudo mount -a - This will mount everything in fstab, and if there are any errors, it will tell you about them now, rather than possibly finding out at boot time.  Depending on circumstances, you may need to unmount first if there was an error, then remount using this command.


Every time I power on my toshipa satilite a105-s2236 laptop (ubuntu 14.04.3) it says "ACPI PCC probe failed" what should I do?

If your system finally boots and works OK, do nothing. If the system doesn't boot, freezes all the time, and it annoys you

back up your files
if your laptop won't boot, unplug it, take your hard drive to any HDD enclosure and copy important files to another computer
download and install a different OS from the USB stick (you may want to Google how to create a bootable USB stick)
choose "erase everything" option during the installation, and don't keep an old OS
see what happens

"ACPI PCC probe failed" message is typical for Ubuntu 14.04 when you install it to a pretty old machine. Choose a system designed for older machines and less resource hungry. Likely you will need Linux Mint Mate 32-bit, because your laptop seems pretty old. If it's the one that initially came with Vista, it's a really old one. It may be just incompatible with some latest Ubuntu versions.


To fix this, follow the steps below:

1- Turn on your computer and wait for it to boot up.

2- Once it boots up, press Ctrl+Alt+F1 to enter terminal

3- Type your username, press enter, and type your password and press enter again.

4- Now type

startx

This should start your desktop. Once here, you can uninstall/reset whatever was causing the problem (in this case Mac OS LightDM theme).

5- Reboot the computer it should boot up normally!


curl unexpected end of file when downloading gzip

It works for me. Is it possible you have a bad network connection? Try to download the file first, and then unpack it, e.g.

wget http://data.biostarhandbook.com/rnaseq/projects/griffith/griffith-data.tar.gz
tar zxvf griffith-data.tar.gz && rm -f griffith-data.tar.gz


How to join windows client to ubuntu OpenLDAP domain server

Historically, Windows and OpenLDAP don't play along nicely. Your best bet may be to use the pGina Windows application to add LDAP authentication to the Windows client in question, over attempting to force Windows to authenticate with OpenLDAP as a default behavior.


All my pictures have disappeared without my deleting them. What should I do?

If all else fails try photorec the 'testdisk' package. (available in the universe software repositories).

you can see if you already have it with the command which photorec which will return the installation path if it's installed.

If not, insure that the universe repository is active by checking the box in software and updates.

What you will need:

1) the drive that contained your missing pictures (this may be obvious but you should not write to this drive until you have attempted recovery as you may overwrite the very data you are trying to recover resulting in further data loss).

2) another drive with sufficient space for your recovered pictures.

3) a live Ubuntu disk or flash drive to boot from (I recommend using an LTS version for this as they are more stable) currently 12.04 or 14.04

4) an active internet connection

5) the ability to read and understand all the steps and options prior to beginning.

Step 1
Boot from the live media described in item 3 with the source (item 1) and target (item 2) drives attached.

Step 2 insure your internet connection is up and running by whatever means you are most comfortable (ping google.com or go there with your browser or whatever)

Step 3

Open a terminal and install photorec with sudo apt-get testdisk

Step 4

Identify your source and target drives with the command sudo fdisk -l you should get output similar to the below and should be able to identify your source and target drives from the differences in the output.

Step 5

If your target drive is new and unused partition it and format it with gparted.

If your target drive already contains a filesystem with needed data skip step 5 (you have been warned)

Step 6 mount the target partition that you have enough space for your pictures. for example sudo mount /dev/sdb1 /mnt (insure /dev/sdb1 is your target, change as necessary to your environment)

Step 7 start photorec by issuing the command sudo photorec

Step 8 adjust options as necessary to enable brute force recovery or deal with low memory, etc as you see fit. Also adjust FileOpt if desired to recover the types of files you are looking for and skip those you aren't. (the default selection recovers many types of files you aren't seeking).

Step 9 use the up down arrow keys to select the partition (or whole disk) you wish to recover data from and the right left keys to highlight search and hit enter. Choose the filesystem type the files were stored on from the choices available, then choose to search either the free space (if you think you deleted them or the entire disk if you have no clue what happened)

Step 10

Highlight the target directory and hit Enter then hit C

Recovery will begin - when complete you should see something similar to this:

PhotoRec  is  file  data  recovery software designed to recover lost
       files including video, documents and archives from Hard Disks and CDRom
       and lost pictures (Photo Recovery) from digital camera memory. PhotoRec
       ignores the filesystem and goes after the  underlying  data,  so  it'll
       work  even if your media's filesystem is severely damaged or formatted.
       PhotoRec is safe to use, it will never attempt to write to the drive or
       memory support you are about to recover lost data from.

If something is unclear, drop me a comment with what exactly you didn't understand and I'll try to elaborate.

Sources: experience, man page


Display scaling setting - difference between Gnome Tweaks and Gnome Display settings

Gnome-Tweaks -- Font Scaling.. means size of the Font is Increased..
Fonts Scaling Factor set to 2

Fonts Scaling Factor set to 3

Display Settings.. is the scaling of all elements..
Displays Scale set to 100%

Displays Scale set to 200%

Based on your needs and resources both the cases are used..


How to use Selenium with aliased Python 3

Python2 and Python3 should be treated as entirely seperate entities and not be intermixed. Python3 cannot use Python2's libraries, and vice versa.

You need to install Selenium under Python 3.

sudo pip3 install -U selenium

Also note that alias python=python3 is not a good idea!


in /etc/grub.d are the config files of grub but they require some programming knowledge to edit them, which I can't provide you, but the tool I use when I get in trouble with grub2 is Grub Customizer wich can help you editing your Grub. You can found it here:

https://launchpad.net/grub-customizer


How resources affected by installed applications in Ubuntu 16.04?

It depends on whether any of the software is automatically started. For example, if you install the MySQL database server package, it will automatically start when the system does and use up processing time and memory.


I need a bitcoin miner, and how to install it?

I would have a look here because there might be a better client and read through all of them. If your mining on a cpu it won't really matter, but any gpu you should seriously consider the software before you mine. Also you should find instructions on the wiki on how to install if not just seek the program homepage by a google search I usually * how to install where *= name of BTC program

https://en.bitcoin.it/wiki/Software


eth0 NO-CARRIER, ifconfig shows no IP address

Try :

ifdown eth0
ifup eth0
ip addr show eth0

The meanings of UP, BROADCAST, and MULTICAST

UP - device is functioning
BROADCAST - device can send traffic to all hosts on the link
MULTICAST - device can perform and receive multicast packets

More about mulicast visit Site


Every app in my Xubuntu 18.04 deleted by Tasksel. Please Help

TL;DR - it is a serious bug

Analysis

Below is available options of tasksel:

$ tasksel --help
Unknown option: help
Usage:
tasksel install <task>...
tasksel remove <task>...
tasksel [options]
    -t, --test          test mode; don't really do anything
        --new-install   automatically install some tasks
        --list-tasks    list tasks that would be displayed and exit
        --task-packages list available packages in a task
        --task-desc     returns the description of a task

Samba task is named as samba-server as you wrote:

$ tasksel --list-tasks | grep -i Samba
u samba-server  Samba file server

It consists of only one package:

$ tasksel --task-packages samba-server
samba-server^

If we try to simulate uninstall - we get the following line:

$ sudo tasksel --test remove samba-server
debconf-apt-progress -- apt-get -q -y \
-o APT::Install-Recommends=true \
-o APT::Get::AutomaticRemove=true -o APT::Acquire::Retries=3 \
install samba-server^-

(in the line above the last hyphen - cause problems).

What I did:

Booted Ubuntu 18.04 LTS clean VM, installed tasksel with sudo apt-get install tasksel
Installed Samba with sudo tasksel install samba-server
Ran sudo tasksel remove samba-server
Rebooted and got broken system on next boot

Fix the system

Then I tried to repair the system:

We need to boot in Recovery mode (click Shift on boot, in GRUB select Advanced options for Ubuntu, select Ubuntu, with Linux ... (recovery mode))
Select resume     Resume normal boot to access login shell
Open first console #1 with Ctrl+Alt+1 then login
If you do not have internet - check Ethernet interface name and run DHCP-client manually on it:

ifconfig -a # got enp0s3
sudo dhclient enp0s3

Reinstall xubuntu-desktop meta-package to the system:

sudo apt-get install xubuntu-desktop

After reboot I can access the system.

Conclusion

So it seems that it is a serious bug - I have found some with almost same symptoms:

bug 574287 reported on on 2010-05-03 - "tasksel: forcefully removes packages when tasks overlap"
bug 1338223 reported on 2014-07-06 - "Tasksel has deleted all my data!".

Also I have filed new bug 1779645 "Critical bug in tasksel: tasksel remove task-name removes whole system"

What to do?

Do not use tasksel for removing things at least on 16.04 LTS and 18.04 LTS.


Found the answer on this page. In case you don't feel like clicking here's the tl;dr:

From the SDL directory you downloaded:
sudo make uninstall ; ./configure --prefix=/usr ; sudo make ; sudo make install


sudo will give you root rights, but not the root environment.

$ sudo su -

this will give you the root environment too, assuming this is the issue.
if it is just root rights for the application you are trying to run, assuming the tool is called modem-tool:

$ sudo chown root:root modem-tool
$ sudo chmod u+s modem-tool

this will make the program modem-tool run with root priviliges

(the commands you need to type are behind the $ sign)


I want to Use grep to search /etc/services

cut -f1 /etc/services | grep -v '^#' | grep 's$'

or

cut -f1 /etc/services | grep '^[^#].*s$'

Explanation

The file /etc/services contains multiple columns while the name of the service is the first one. To print the first column of a file that uses tabs (\t), use cut -f1 (f stands for field).
There are also comments in the file which start with a # symbol. The command grep -v '^#' filters them out.

-v prints lines not containing the pattern,
^ means the beginning of the line.

Now we get the list of services which can be simply filtered using grep 's$'.

$ means the end of the line.

Alternatives

The two grep calls can be combined into one: grep '^[^#].*s$'. This regular expression looks for the lines fulfilling all of the following rules:

not beginning with # (to be more exact: beginning (^) with a character not equal to # ([^#])
followed by an unspecified number of any characters (.*) and
having an s right before the end of the line ($).

The commands sed or awk could get the job done, too.

Dealing with duplicates

You might find that the service names are listed multiple times since they use multiple ports. (This information is covered by the second column which we’ve filtered out.) There is a command to print every item once and in alphabetical order at the same time: sort --unique.
Simply pipe the output of the previous command to sort:

cut -f1 /etc/services | grep '^[^#].*s$' | sort --unique

See also

man grep
man cut
man sort
https://www.regular-expressions.info/


Update manager notifications not getting in Kubuntu

Checklist

1) Is the "Check for updates" enabled ?

kdesudo software-properties-kde

2) Is the System Notification for the updates enabled ?

KDE System Settings > Application and System Notifications > Manage Notifications; Event source: System Notification

At here: When those are enable the Kubuntu/KDE is checking the updates and notifying those.

Q & A

  August:   i don't have that option

Do you have the package: muon-notifier installed ?

  Description: update notifier for KDE
  The Muon Notifier is an update
  notification daemon for KDE. It uses the KDE  Daemon frame (KDED)
  framework to present the user with update notifications,  providing an
  opportunity to launch the Muon Updater to deal with these  updates.

  Homepage: https://projects.kde.org/projects/extragear/sysadmin/muon/


How to use `gsettings set` to configure GNOME shell extension called Arc Menu?

what happens is when you install this extension..

the directory arc-menu@linxgem33.com is installed here ~/.local/share/gnome-shell/extensions/arc-menu@linxgem33.com

If you list the contents..

ls .local/share/gnome-shell/extensions/arc-menu@linxgem33.com/schemas/

Example:

pratap@i7-4770:~$ ls .local/share/gnome-shell/extensions/arc-menu@linxgem33.com/schemas/
gschemas.compiled  org.gnome.shell.extensions.arc-menu.gschema.xml
pratap@i7-4770:~$

the gschema.xml file is here.. you need to copy this to $HOME/.local/share/glib-2.0/schemas/

Note: check the directory glib-2.0/schemas is already available under $HOME/.local/share/ or not. If not create the directory first.

cp .local/share/gnome-shell/extensions/arc-menu@linxgem33.com/schemas/org.gnome.shell.extensions.arc-menu.gschema.xml .local/share/glib-2.0/schemas/

and then compile

glib-compile-schemas $HOME/.local/share/glib-2.0/schemas/

Once it is successfully compiled with the above command..

now you can use gsettings or dconf

Example:

pratap@i7-4770:~$ gsettings get org.gnome.shell.extensions.arc-menu custom-menu-button-icon
'/home/pratap/1.png'
pratap@i7-4770:~$ gsettings get org.gnome.shell.extensions.arc-menu menu-button-icon
'Custom_Icon'
pratap@i7-4770:~$

Please note that when ever you remove the Arc-Menu Extension via Ubuntu Software

remove the schemas file for this Arc-Menu $HOME/.local/share/glib-2.0/schemas/org.gnome.shell.extensions.arc-menu.gschema.xml

rm $HOME/.local/share/glib-2.0/schemas/org.gnome.shell.extensions.arc-menu.gschema.xml

and compile..

glib-compile-schemas $HOME/.local/share/glib-2.0/schemas/


You didn't specify what type of package you wish to build.  I'm going to assume that you want to build a click package, suitable for installation on an Ubuntu phone.

If you're using Qt Creator with the Ubuntu SDK plugin, there is a "Publish" tab on the the left-hand side. Select that, and then click the "Build and validate click package" button.  The click package will be placed in your build directory.

To build a click package from the command line, first place all the files into the correct (relative) hierarchy in a temporary directory.  The manifest.json file must be in this directory.  Keep in mind that any architecture-dependent files must have been generated in an appropriate chroot.  You probably want your make install step to set this up for you.  Then run click build /path/to/temp/directory, and you'll get the click package, named with the appropriate values from the manifest file.

Click packages are very similar to deb files.  You can inspect their contents with file-roller, but only if you rename them to end in .deb.

For more details about building click packages, including some helpful commands for building in chroots, see this blog post.


To free pagecache:

echo 1 > /proc/sys/vm/drop_caches

To free dentries and inodes:

echo 2 > /proc/sys/vm/drop_caches

To free pagecache, dentries and inodes:

echo 3 > /proc/sys/vm/drop_caches

use with root permissions


compare two lines and print unmatched words from two files

It seems you have two files with a huge line each, which contains (space) separated tokens.
The diff tool is good for line matching. For items within the line you will have to be a bit more creative.

For example

:~$ cat file1
a b c d

:~$ cat file2
b d

:~$ cat file1 | sed 's/ /\n/g' |grep -vf <(cat file2|sed 's/ /\n/g') | tr '\n' ' '; echo

a c

we can use another line-oriented tool to exclude lines from the input stream by using a list of lines provided as a temporary file.

 sed 's/ /\n/g'

converts spaces to new lines

 grep -v

excludes the filter condition from the input stream

grep -f
uses the list of conditions/lines from the provided file

<( ... )

create a file handle from sub-process output

 tr '\n' ' '

converts new lines back to spaces. However, there will be no line at the end, so we add a trailing echo.

The same thing can be achieved using [g]AWK as it has built-in maps. You will have to set the record separator to space.

and if using the updated example we get:

>cat file1
eipassoc-03cd9117d7188d2 eipasoc-47367a3f eipasoc-bbbddc3 eipassoc-10bbfb6
>cat file2
eipasoc-47367a3f eipassoc-10bbfb6
>cat file1 | sed 's/ /\n/g' |grep -vf <(cat file2|sed 's/ /\n/g') | tr '\n' ' '; echo
eipassoc-03cd9117d7188d2 eipasoc-bbbddc3
>
>

If you are inclined to use AWK here is an example:

>cat file1
eipassoc-03cd9117d7188d2 eipasoc-47367a3f eipasoc-bbbddc3 eipassoc-10bbfb6
>cat file2
eipasoc-47367a3f eipassoc-10bbfb6
>cat file1 | sed 's/ /\n/g' |grep -vf <(cat file2|sed 's/ /\n/g') | tr '\n' ' '; echo
eipassoc-03cd9117d7188d2 eipasoc-bbbddc3
>
>

Here I am using a hack to treat the first file as a lookup (NR==FNR) and store the lines read in a map, and then the non-first files will be checked against the lookup.You get record separation for free but the the code becomes obscure because it depends on side-effects


You have to fix the line 52 of your sources.list with command below:
sudo sed -i '52s|.*|deb https://dl.winehq.org/wine-builds/ubuntu/ bionic main|' /etc/apt/sources.list


Find outr which IPs are from program and which IPs are from addons

Two ways of doing this come to mind:

Run the application under the control of strace which logs all system calls, including attempts to connect.

Let's say you want to run firefox and see what it connects to:

# Start the process under the control of strace, logging only network-related calls:
strace -e trace=network -o network_calls -f firefox

# After finishing working with firefox, print the IPs it tried to communicate with:
grep -o -P '(\d+\.){3}\d+' network_calls | sort -u

This can be scripted, for the strace to be running constantly and the logfile being periodically rotated, etc. but the method below is more suitable if you'd like to leave the app running for a longer time and avoid having to write scripts.

Run the application as a different user and add iptables rules that match based on the process owner UID and act accordingly.

Example dropping network traffic of a user with UID 5555:

iptables -A OUTPUT -m owner --uid-owner 5555 -j DROP

You could replace DROP with LOG, do whatever else you wish, such as throttle connections, select ports you wish to deny, etc.

Add a comment if you'd like me to expand on a specific approach and I should be able to update my answer.


No WiFi and Neworking connection on Ubuntu 16.04

I solve the problem using:

sudo apt-get remove --purge resolvconf && sudo apt-get install --reinstall resolvconf


Clicking on nautilus opens new window rather than opened ones

Since shift-clicking did not work for me I searched and found another solution.

Workaround mentioned in the corresponding bug report: Scroll the mouse wheel on the Nautilus icon.


What has Jockey been replaced with in 14.04?

Open the terminal and type:

sudo apt install ubuntu-drivers-common

ubuntu-drivers-common detects and installs additional Ubuntu driver packages.

This package aggregates and abstracts Ubuntu specific logic and knowledge
about third-party driver packages, and provides APIs for installers and driver
configuration GUIs. It also contains some NVidia specific support code to find
the most appropriate driver version (as Ubuntu usually ships several), as well as
setting up the alternatives symlinks that the proprietary NVidia and FGLRX
packages use.

Command line interface

The simplest frontend is the "ubuntu-drivers" command line tool. You can use
it to show the available driver packages which apply to the current system
(ubuntu-drivers list), or to install all drivers which are appropriate for
automatic installation (sudo ubuntu-drivers autoinstall), which is mostly
useful for integration into installers.

See also: Can I install extra drivers via the command prompt?


Network sharing mounted device. Guest access - permission problem. U.18.04

Edit /etc/samba/smb.conf and add a line under workgroup = WORKGROUP :

force user = kjahsdf

Replace kjahsdf with your Ubuntu login user name.

Then restart smbd:

sudo service smbd restart

Reason: Cannot access shared floder on ubuntu from windows 10 meanwhile I have access to default Public folder


How to play Geovision video files in Ubuntu

There is a sample geovision file on the MPlayer sample site that can be downloaded as follows:

wget samples.mplayerhq.hu/V-codecs/GAVC/GeoVision_camera.avi

This file plays quite easily with SMPlayer:

sudo apt-get install smplayer

Below is a screenshot of this file playing quite successfully on my own system:

Not a very exciting film clip I am afraid but you get the idea :).


Wireless network card not working on Acer E5-574G

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

wget http://mirrors.kernel.org/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.158_all.deb
sudo dpkg -i linux-firmware*.deb

Reboot and your wireless should be working correctly.


11.10 x86 - memory RAM problem (shows 3.4 GB when 8 GB are installed)

The PAE kernel gets installed by default if the 32bit installer detects 4GB or RAM or more. Something must have gone wrong with that detection or you may have had less RAM at the time of installation, and upgraded later.

Regardless, you should use the PAE kernel which will see all the RAM. Install the linux-image-generic-pae package which should pull in the latest PAE kernel, and if all goes well, remove the generic kernels.


Snapping to the side of the screen in GNOME disables the resizing of the window

Unfortunately it's an intended half-tiling feature (you may call it a bug if you wish) and it seems there's no workaround. There was an option to do it by super+middle mouse button drag in older versions of GNOME shell, but it seems it's been dropped.
According to a one OMG! Ubuntu! article, GNOME v3.26 (the one to be shipped with Ubuntu 17.10) has a feature which lets users tile windows to available width (not an arbitrary 50%) [see this video demo] and resize both the half-maximised windows at the same time just by resizing one or other.
For advanced tiling options you may look for some extensions in extensions.gnome.org, for example:

zTile
gTile
Tilingnome
shellshape
ShellTile

etc.

Update from the original asker
I tried some of these extensions. zTile, gTile seem a bit buggy at the moment (at least with my current configuration). I tried ShellTile and can confirm that this does fix this "issue".


How do I find out what webcam driver is in use?

Use the following command to see all the loaded driver modules in the system.

Open terminal then type

lsmod

And see if your driver is listed in the modules or not

there is also another command that list the PCI modules

lspci


My system screen goes black and displays Term Signal Killed?

If it locks up randomly and not associated with a particular process (program you are running) then two thoughts come to mind.  You could have a bit of flaky memory that doesn't always get spotted right away.  The easy way to find out is to run the memory test from the boot cd - I'd let it churn overnight.

The other issue is that it might be heat related.  Any chance your processor fan has stopped?


Is it acceptable to subscribe someone else to a bug report?

I think it's acceptable--even encouraged--and part of the Ubuntu/FOSS community spirit; it's allowed because we trust ourselves not to frivolously subscribe people to random bugs which may not interest them. The subscribee can always choose to unsubscribe, if necessary. Note that subscribing is restricted to Launchpad users, most of whom presumably have some tangential interest in the software development aspect of Launchpad.


Problem Loading UEFI:db X.509 certificate (-65)

I've had the exact same error message while trying to install Lubuntu. I solved it by changing the BIOS boot setting to a setting that was not UEFI ; CSM in my case. My laptop is a Toshiba C855D-S5303. Am AMD Dual-core 300E. Although I still recieved an error message about "no IRQ handler" Lubuntu would install.


Upgrade problem 12.04 to 14.04: screen blank on reboot, but recoverable

The problem was traced to a failing monitor. Plugging in a newer monitor has fixed it. I recommend trying this for any blank screen problems with upgrades.


I have the same motherboard and the HDMI sound is working (sound is coming out of my screen) but the front and back jacks are not.

I only installed a recent kernel, maybe you can try that too? I used UKUU but you can also download them directly from https://kernel.ubuntu.com/~kernel-ppa/mainline/ and install them with dpkg -i.

You should also try to upgrade your nvidia proprietary drivers.

For the record, here is the information of my system with HDMI sound working:

inxi -SMA
System:    Host: euclide Kernel: 5.6.11-050611-generic x86_64 bits: 64 Desktop: Gnome 3.36.1
           Distro: Ubuntu 20.04 LTS (Focal Fossa)
Machine:   Type: Desktop System: Gigabyte product: B450M DS3H v: N/A serial: <superuser/root required>
           Mobo: Gigabyte model: B450M DS3H-CF v: x.x serial: <superuser/root required> UEFI: American Megatrends v: F50
           date: 11/27/2019
Audio:     Device-1: Advanced Micro Devices [AMD/ATI] Raven/Raven2/Fenghuang HDMI/DP Audio driver: snd_hda_intel
           Sound Server: ALSA v: k5.6.11-050611-generic

aplay -l
**** Liste des Périphériques Matériels PLAYBACK ****
carte 0: Generic [HD-Audio Generic], périphérique 3: HDMI 0 [HDMI 0]
  Sous-périphériques: 1/1
  Sous-périphérique #0: subdevice #0
carte 0: Generic [HD-Audio Generic], périphérique 7: HDMI 1 [HDMI 1]
  Sous-périphériques: 1/1
  Sous-périphérique #0: subdevice #0
carte 0: Generic [HD-Audio Generic], périphérique 8: HDMI 2 [HDMI 2]
  Sous-périphériques: 1/1
  Sous-périphérique #0: subdevice #0

I would be very interested to know if your jack are working?


Seems to be a bug. Check here (answers #10 and #16):
https://bugs.launchpad.net/ubuntu/+source/dolphin/+bug/1509562

In short: installing package 'libqt5libqgtk2' before 16.04 and 'qt5-style-plugins' for 16.04 and later brings back MOST of the icons in KDE-Applications. For the few remaining ones, you have to fiddle around with the icon-settings in KDE-System-Settings.

HTH


You can not use mount with different options for the 2nd time you mount it.  So that is a no.

This is possible:

mount -t ext3 /dev/sda7 /home/first
mount -t ext3 /dev/sda7 /home/second

This is not ...

mount -t ext3 /dev/sda7 /home/first
mount -t ext4 /dev/sda7 /home/second

The disk you mount does not magically transform from ext3 to ext4 when you tell mount it is ext3 now and ext4 next. It will error out with a "wrong fs" notice.

If you want you can use the "bind" method to create a mount point with different options ...

mount -t ext3 /dev/sda7 /home/first
bindfs -r /home/first /home/second

would have you end up with /home/second that is read-only (and /home/first as writable if mounted as writavle). You can use it remap user ID and groups but it still needs to be the same file system. That is what is used on the partition itself not something you set when you use "mount".


I have same problem with my Lenovo T500 and Ubuntu 12.04. The only release that was working for me was 10.04. With that my laptop didn't overheat. Since that time I have always problems. It doesn't help not even jupiter or indicator-cpufreq. Problem is that is not overheating just the processor but entire laptop. When I have Windows running, my laptop is much more cooler. My opinion is that there is still some problems with kernel. The only solution for me was to put AC - powersave mode in BIOS. But this solves just the temp of processor.


How to wildcard directories and all files in them

One possible workaround is to use somethig like:

find . -iname *.pdf | xargs -I% pdf2djvu -o % %.djvu

This would find all pdf files starting in the current directory (recursive) and run the pdf2djvu command to produce file.pdf.djvu files.


I am no expert and just an average user, but in the past I had success running a newer or older kernel version than the one causing the problem.


What is the most secure way to use sudo permissions in a script?

The easiest solution is merely to enable your script in sudoers.  This should not introduce problems like having the script replaced ... so long as none of the parent directories are writable to non-root users.  However, any security bugs in your script would be run as the target user, which might introduce something unsavory.

The safest solution is to either escalate only when necessary using sudo within your script or else to write your script very carefully and get its code audited by somebody familiar with your security concerns.

In @muru's second comment to the question, it was supposed that the simpler the scripting language (and the code), the less prone it is to having a security flaw.  I agree with that.  Limiting it to dash (assuming you've got dash as /bin/sh) will indeed help on that.  Using a more comprehensive language like python increases the possibilities for both what you want and what might go wrong, so I'd only suggest it if you're more comfortable with it than a simple POSIX shell script.

Ultimately, this depends on what your code does.  Figure out your risks and how much effort it would take to control them, then weigh each against the other.  Who could abuse this?  Sudo leaves an audit trail, so is the threat of being fired or expelled enough to keep would-be abusers in line?


[ubuntu19.10]cant boot into unless using sudo mount -o remount,rw /

/dev/mmcblk0p2  /               ext4    defaults,noatime  0       1

adding something like this solved the issue


.How do I make use of nvidia graphic card in linux?

I experienced the same with a GTX 870m.
Here I tell you what to do :)
first install the driver for intel: https://01.org/linuxgraphics/
then install the nvidia driver, that aren't still avaible from 'aditional drivers'.
How?
sudo apt-get install linux-headers-generic
sudo apt-add-repository ppa:xorg-edgers/ppa
sudo apt-get update && sudo apt-get upgrade
Then reboot and go with Bumblebee to change the card to your liking.
sudo add-apt-repository ppa:bumblebee/stable && sudo apt-get update
sudo apt-get install bumblebee bumblebee-nvidia primus nvidia-331
This worked for me.
Regards, Vìctor.
Sorry 4 my english!!


Sublime Text not showing in Nautilus "open with" menu

Copy the contents of /usr/share/applications/sublime_text.desktop to ~/.local/share/applications/sublime_text.desktop

Or simply use:

cp -it ~/.local/share/applications /usr/share/applications/sublime_text.desktop

Then in the terminal type: sudo update-desktop-database


Is there a way to restore ubuntu 12.10 to default.

The way to do that is just to reinstall.
I would recommend installing 13.04 considering that comes out today and if you want longer support, grab 12.04.2 LTS not 12.10.


Boot from a live CD and fix your partitions using gparted.

See here the usage of gparted.


Remap Dell L502X touch keys on Ubuntu 16.04

There are multiple ways to do this, but the easiest is the below.

Open keyboard settings (System Settings-->Keyboard)
Click on the shortcut tab and using the left navigator pane try to identify whether there is a shortcut that does what you're looking for.
If there's not, click on the plus symbol at the bottom of the window.
Enter an identifiable name for the shortcut.
Type in the command (as you would in terminal) to access the program you want to open and click apply.
By default your shortcut will be disabled, click where it says disabled to change the text to set accelerator
Enter your shortcut as you normally would holding down the dominant key first i.e. ctrl or alt. or the exact key if no dominant key is needed.


How can I allocate more space to my root partition?

You can only resize physical partitions. Please have a look at:

What are "/run/lock" and "/run/shm" used for?

/run/shm is shared memory.

You could use a utility like Disks from the Unity menu to understand the physical disks you have and how they are partitioned.

You might also want to look at what actually uses most disk space and whether you really need all that is there. For example, if the system has been running for a while and been updated again and again, then it is worth having a clear-out in /lib/modules of older kernel modules that you don't actually need any more.

You can check how much space is used by a directory by using the command

du -s /lib/modules

or for any other directory.


How do I disable automatic screen locking in Xubuntu?i have tried many ways but still not working

Check the lock tab under screen saver (which in in applications off a right click of mouse on the XFCE desktop)


Can and should UDF be used as a hard drive format?

Someone did some research into how to format a flash drive with udf so it can be used on as many operating systems as possible. Here are his findings (used to be there, now offline):

Windows 7 have full support up to UDF v2.6, but the UDF block size must match the block size of the underlying device (which for USB-sticks and most disks is 512 bytes; "advanced format" disks are 4096 bytes). Apparently the disk must be partitioned.
Linux 2.6.30 and up supports UDF fully at least up to version 2.5.
Mac OS X 10.5 supports UDF fully up to UDF 2.01, but only when used on a full disk, so not partitioned.

As explained above, for USB harddisks, Windows requires the disk to be partitioned. On the other side, UDF only works in OS X when it is used on a full disk (unpartitioned). Rather surprisingly, there is a solution which works for both: having the disk partitioned and unpartitioned at the same time.

DOS partition tables are stored in bytes 446-510 of the master boot record. This master boot record is stored in the first sector on disk, sector 0. Typically, the first partition specified will start some kilobytes further. However, it seems possible to construct a partition table whose first partition starts at sector 0, so the result is a partition which contains the partition table itself. Partition editor programs seem to refuse to create such a table, but at least recent Linux and Windows kernels don\u2019t seem to bother.

The nice thing is that UDF does not (I suppose deliberately) use the first few kilobytes of the partition or disk it is placed on, so this place can really be used to store a legacy partition table, referring to a partition that spans the whole disk. Some testing shows that this really works on Linux, Windows and Mac OS X:

Mounts automatically read-write in Linux 2.6.30+, Mac OS X 10.5+, Windows Vista+
Can be used read-only in Windows XP, and be used after a command line mount in Linux 2.6.0+
Supports large files, UNIX permissions, Unicode filenames, symlinks, hardlinks, etc.

Script to format the disk properly: Perl script or Bash script


Press super key
Enter Gparted
Select it
Select any big ext4 disk right click>unmount again right click>resize partition....reduce some space and make around 70 to 80 gb space which is unallocated.. apply settings make bootable pendrive of Ubuntu 14.04 and follow this..
Boot ur pendrive
And select install ubuntu and then...
(Images are of 16.04 doesn't matter and here free space is 150 u can allocate accordingly)

Neglect along side windows option this is not your case. select something else
Continue installation...reboot after completion.. hope this helps :)

Edit :FOR LVM RESIZING
REFER TO How can I resize an LVM partition? (i.e: physical volume)


image + audio = mp4: how to make video smaller?

For uploading to YouTube

H.264: smallest files

This method uses libx264 to encode H.264 video. It is slower than the stream copy method below, but potentially will output a smaller file size.

ffmpeg -loop 1 -framerate 1 -i image.jpg -i music.mp3 \
-c:v libx264 -preset veryslow -crf 0 -c:a copy -shortest output.mkv

Stream copy: fastest process

This method just stream copies (no encoding) the image into the MKV container. It's super fast, but if size is important than the method above may produce a smaller file.

ffmpeg -loop 1 -framerate 1 -i image.jpg -i music.mp3 -c copy -shortest output.mkv

YouTube accepts just about anything so these commands use a few tricks to make encoding faster, or make the file size small, and to keep quality high because YouTube will re-encode whatever you give it. Your player probably won't like it but YouTube will.
In these examples a very low frame rate is used which should process faster than the default of 25 fps.

Widest compatibility for any player

ffmpeg -loop 1 -i image.png -i music.mp3 -vf "scale='min(1280,iw)':-2,format=yuv420p" \
-c:v libx264 -preset medium -profile:v main -c:a aac -shortest -movflags +faststart output.mp4

This should play on just about anything except very ancient devices (change -profile:v main to -profile:v baseline if that is the case).
If your audio input is already AAC then change -c:a aac to -c:a copy to avoid unnecessary re-encoding.
Encoding time will be longer and file size will be bigger than the YouTube commands above.
See FFmpeg Wiki: H.264 for more info.


Don't worry, there is no danger, follow this little guide to resolve the problem.

These messages are not dangerous, after a while LVM (a software abstraction over your disk) will scan the partitions and your system will boot normally. There is a delay due to the lack of optimization, since lvmetad is a system service (daemon) that caches the LVM condition to prevent useless disk accesses and it does not start soon enough (probably for a bug or misconfiguration).

Ubuntu Desktops doesn't need it to work.

Solution

Open a Terminal (CTRL+ALT+T or search in Dash), write sudo -H gedit /etc/lvm/lvm.conf and press ENTER (insert your user credentials).
In the editor find:

use_lvmetad = 1

...and change the line to:

use_lvmetad = 0

Do not make other changes, you only need to change a single number and save the file. After this, you may close the Terminal or log-off from the VT.

This will disable any attempt to use the lvmetad daemon and if your disk configuration is simple enough your boot will be faster and any LVM command will not try a new connection to the system bus of lvmetad. You may notice more disk activity, this is a normal behavior.

The warnings will remain, this is the right behavior and it doesn't have side affects.

Please note: this is a good but temporary solution, future GNU/Linux versions will not need this procedure.

Optimization

After the edit, you may also execute (in the same type of Terminal) the command sudo systemctl disable lvm2-lvmetad.service to disable lvmetad completely.

This is not necessary and you should contact your system administrator before doing it.

What NOT to do

Never boot with the nomodeset option enabled, because it WILL disable many GPU features and your graphics card may not work correctly. Ubuntu Desktops will not work correctly with this option enabled, because Unity (and successive GUIs) and many applications need the graphic acceleration and the advanced GPU features.
This option must be only used to debug graphic drivers or to start a system without the right graphic drivers.
Important: on some systems the user may need to disable this option in GRUB to login, while other systems will simply be slower but usable.

EDIT (10/03/2017): after disabling the service and upgrading one of my Debian machines (Ubuntu is based on Debian) I noticed that the warning disappeared. The upgrade installed the kernel Linux 4.9.0-0.bpo.2 for AMD 64 (64-bit). It can be temporary or limited to some architectures, but it is a step forward, also because Ubuntu can inherith the change.
I suppose that a developer saw this message and they are working on the problem. Well done FOSS.

Fell free to comment under here if you need more help and don't forget to press the left UP arrow and accept the answer.


What software is available for Book Publishing?

It has a very steep learning curve, but I  think that the best option for books is still LaTeX, unless your book is very images-oriented. The fact that is basically a language hinders the start, but then gives you a flexibility that is difficult to find in other programs.

It is very well supported in Ubuntu, and has even a very friendly and useful
Stack Exchange site.

You can get started or explore the system here: https://tex.stackexchange.com/questions/155863/getting-started-with-tex-latex


How to partition SSDs for dual-boot Kubuntu and Mint

Often to avoid issues, easier to just disconnect one drive when installing. Most desktops do not need separate /boot unless using LVM with full drive encryption (and that may not be required now). And newest Ubuntu versions use swap file. It will use a swap partition if one is found during install. If UEFI and not disconnecting drive, you must manually partition in advance and include ESP on both drives.

Partition in advance:

How to prepare a disk on an EFI based PC for Ubuntu?

Partitioning during install, but you will not get ESP on second drive unless a drive is disconnected:
How to use manual partitioning during installation?

With multiple installs do not share /home or /boot or any system partition. If you want data shared best to have a separate data partition. I use /mnt/data and link folders into each install. Details:

storing data on second HDD, mounting


Calibre on Ubuntu 18.04 installed in wrong language

Check out this file - it's a configuration file for Calibre:

/home/[username]/.config/calibre/global.py.json

Look for "language" string and change it to "en". Example of my config:

"isbndb_com_key": "",
"language": "en",
"library_path": "/home/mp/1/ebooks/calibre",


Is it not possibly to upgrade to Natty using a live CD if there are multiple systems installed?

I think that is a bug. I just installed Ubuntu Natty beta 2 today evening on my laptop which dual boots maverick and windows 7. I did the installation using the live CD and was given the option to upgrade leaving personal files intact.

However I did a clean install just to get a fresh start.


Ubuntu Desktop 14.04 halts on bcmwl-kernel-source(i386)?

Thanks for responding. My apologies for returning to my question months afterwards...  The problem was caused by an option for 3rd party software / updates option, after the regional/time setup stage...  If the 3rd party thing is unchecked, the installation is successful, without any wireless complaints.


My AMD/ATI HD 7570M is overheating after install Ubuntu 12.04.2

I had the same experience and the only solution for me was to use the KDE desktop instead of Unity. I tried to install the AMD video drivers directly from AMD first however all that happened for me was that it killed Unity and I saw a blank screen when I logged in.

If have found that the 12.10 version of Ubuntu is not stable on AMD machines. Even with the switch to the KDE desktop, the performance while better was nothing near the performance of my 11.x versions of Ubuntu. Lucky I still had my old instance and could revert back to it.

Give this a try and good luck.

http://support.amd.com/us/gpudownload/linux/legacy/Pages/legacy-radeon_linux.aspx


The package system is broken: I can't update my apps on Ubuntu 12.10 64bit

First, try this commands in the Terminal (CTLR+ALT+T):

sudo apt-get update --fix-missing
sudo dpkg --configure -a

If your problem still persists, try downgrading (using Synaptic Package Manager) the packages:

libc6
libgcc1
libstdc++6
libudev0
zlib1g

Tutorial about downgrading packages

Hope it helps!


RDP from Windows 10 to XRDP on 17.0.4 = RDP crash?

Are you logged in to the machine locally while trying to connect remotely? It seems like in the xrdp setup in 17.04 you can no longer do that.


What does it mean when I type a command and the terminal does nothing?

I would quote Eric S. Raymond's The Art of Unix Programming:

  Rule of Silence: When a program has nothing surprising to say, it should say nothing.

  One of Unix's oldest and most persistent design rules is that when a program has nothing interesting or surprising to say, it should shut up. Well-behaved Unix programs do their jobs unobtrusively, with a minimum of fuss and bother. Silence is golden.

  This “silence is golden” rule evolved originally because Unix predates video displays. On the slow printing terminals of 1969, each line of unnecessary output was a serious drain on the user's time. That constraint is gone, but excellent reasons for terseness remain.

    I think that the terseness of Unix programs is a central feature of the style. When your program's output becomes another's input, it should be easy to pick out the needed bits. And for people it is a human-factors necessity — important information should not be mixed in with verbosity about internal program behavior. If all displayed information is important, important information is easy to find.

    -- Ken Arnold

  Well-designed programs treat the user's attention and concentration as a precious and limited resource, only to be claimed when necessary.

Of course, many programs don't obey this rule, and the answer really depends on the particular program.


Install from ppa:jonathonf/ffmpeg4 403 Forbidden [IP: 91.189.95.83 80]

The ppa:jonathonf/ffmpeg4 has been removed.

See https://launchpad.net/~jonathonf/+archive/ubuntu/ffmpeg-4

  This PPA has been removed from public access as part of a protest
  against the abuse of open-source projects by large companies. For more
  detail visit the main page here: https://launchpad.net/~jonathonf


WEBCAM software with Motion Detection help with MOTION

If you're looking for a simple program to do motion detection I would choose a script using OpenCV like this one:

https://github.com/RobinDavid/Motion-detection-OpenCV

Or just download the first script and install python-opencv:

sudo apt-get install python-opencv

To run the script just type in a terminal:

python ./MotionDetector.py


Mail Gateway / Antispam for Linux Ubuntu Server

Ubuntu offers a choice of SMTP (email) servers. My preference is Exim4, but others prefer Postfix.  Both of these integrate with spamassaassin (for spam filtering) and clamav (for virus scanning).  Clamav regularly downloads updates, and spamassassin has rule database feeds.

I am not sure what you mean by "ComdoAV for win because of needing graphical environment".  A fully functional email server can be run on the Ubuntu server version which does not have a graphical environment.  There are various graphic packages that can be installed if desired.

In today's environment, setting up the software is the easy part.  Getting appropriate connectivity (static IP address), and setting up the various resources in DNS takes a bit of work.  See the canonical answers on ServerFault such a https://serverfault.com/questions/419407/fighting-spam-what-can-i-do-as-an-email-administrator-domain-owner-or-user?s=3|0.2216


Can't connect to remote desktop from Windows

Yes, this is an understandable confusion. I reported it as a bug and it's been fixed in 11.10. "Remote Desktop" in Ubuntu is not the same thing as in Windows. It's intended to share your running desktop with someone else. In 11.10, it's been renamed to "Desktop Sharing" to better reflect that. It also uses another protocol, VNC, so if you want to connect to your shared desktop from Windows, you'll need to install a VNC viewer. There are many of them to choose from.

It is also possible to connect to Ubuntu using the Windows built-in client. You'll need to install xrdp, but the last time I tried, it was not easy.


Virtual Machine error while starting Windows XP: VT-x is disabled in the BIOS

Here the answer for the sake of completeness from AlexP comments:

  For starters, if you want to run virtual machines you should enable
  VT-x in BIOS setup.