Install Ubuntu on late 2006 Macbook Without CD

This is a method to install Ubuntu on your MacBook using FireWire Disk mode. I had the same problem with the optical drive in my MacBook from late 2006 after pouring milk into it late one night and did get a working install this way. You will need another Mac with FireWire and a FireWire 400 cable. If the other Mac has FireWire 800, you will need a FireWire 400 to 800 cable. And you will need a disk to backup your Mac OS X install. (You also need this backup of Mac OS X to extract the firmware for your iSight webcam after the install.)

Maybe borrow another Mac from somebody if you don't have two. The other Mac must run Mac OS X 10.4.7 or later (PowerPC or Intel doesn't matter), since otherwise it will not be able to "see" the disk in the MacBook. (PowerPC Macs used APT, not GUID partition tables, so only after the Intel transition did the operating system get the ability to see GUID disks.)

What you basically do is install the Live DVD to one partition and install onto the rest of the disk from that partition. If you want to dual boot, you can restore your Mac OS X install to the partition we used for the Live DVD after installing Ubuntu on the other partition, but if you just want Ubuntu, then keep the other partion as a restore partition. Before partitioning, you will need to know if you want to dual boot or not to decide how large the partition you will use for the Live DVD should be. If you want to dual boot, you will have to make it as large as you want your later Mac OS X partition. If not, then it will just need to be large enough to fit the live .iso.

(I am not using the English localisation of neither Mac OS X nor Ubuntu, so the exact worthing of buttons and such might be slightly off in these instructions, but the gist of it is right.)

Here is how you do it:

Backup your Mac OS X install to an external FireWire or USB drive. Use Carbon Copy Cloner from Bombich software (not Time Machine) if you want to dual boot. (We need an exact clone that we can restore to one of the partitions on your MacBook later, and since we can not use the Mac OS X Install disk to restore from a Time Machine backup since the optical drive doesn't work, we need an exact clone that we can restore with Disk tools from the other Mac.) NB: If you want to dual boot, make shure that your Backup does not take up more room than the size you will use for the Mac OS X partition later. (Delete all unnessecary stuff from your home folder if it is too large.)
Download and install rEFInd and restart your MacBook twice (not one time, but two times) and shut it down again.
On the other Mac, download Ubuntu 14.04 AMD64/Mac or 14.10 AMD/64 Mac. After it is downloaded, click it and press Commando+I to get the "Get info" window. You need the information in this window later.
Connect the FireWire cable to the other Mac and start your MacBook while holding down the T key. A FireWire symbol appears (looking like a flux capasitor) and on the other Mac, your hard drive appears in the Finder.
Open Disk tools. (In the Tools folder inside the Program folder.)
Select your MacBook's disk in the left panel and click the partition tab.
Make a new partition by hitting the + on the lower left side. Drag the dividing line between the partitions upwards or downards untill it is the size you want.
a) Single boot. If you want to just have Ubuntu on the MacBook, you will have to make it the size of the live iso file we downloaded earlier (look at the "Get info" window now). Add an extra gigabyte just to be shure (since sometimes a gigabyte is 1024 MB and sometimes it is 1000 MB).
b) Dual boot. If you want to dual boot with Mac OS X, you will need to make your partition the size you want your Mac OS X partition to become later. Remember that this has to be bigger than the backup clone you made in 1 to work.
Make the new partition MS-DOS (FAT32) formatted by writing a name in the field to the right of the partition layout and selecting MS-DOS and then "delete" (or "Partition". Can't remember exactly).
Drag the .iso file from the Downloads folder into the left panel of Disk tools.
Click the "restore" tab and drag the Ubuntu live iso into the "From..." field and the new partition you made in 7 into the "To..." field and click "Restore".
Quit Disk Tools.
Eject the two partitions from the MacBook in the finder by clicking the eject buttons on the right side of their names.
Shut down your MacBook. (Hold down the power key untill the MacBook shuts down if it doesn't shut down immideatly.)
Disconnect the FireWire cable.
Restart your MacBook.
Choose "Windows" when the rEFInd window shows up. It thinks it is windows because the disk is formatted FAT32.
Choose install and go through the usual questions. (Tap to click is on by default, so be careful with your trackpad.) I usually choose not to update the installer, as it often seems to fail for me, but check the Fluendo restricted multimedia package, that is really nice to have. When you come to the place where you should choose where to install, choose "Manual setup" (or whatever it is called). DO NOT choose erase the whole disk and install (since the live iso you are running is also on the disk).
Delete the other partition of the disk (the HFS+-formatted one) and make a Swap partition the same size as your RAM (3,3 GB if you have maxed the RAM in your machine) and another EXT4 partition that you make your root partition. Press "format" after setting the disk up as you like. (DO NOT repartition the FAT32 partition or do anything else with it at this time.)
Install and when asked, choose to install grub on your root partition. (The EXT4-partition.)
Restart.
Dual boot only. Shut down your MacBook. Connect your Backup USB or FireWire disk to the other Mac. Reconnect your MacBook to the other Mac with the FireWire calbe and start the MacBook while holding down T. Choose "Ignore" when asked what to do with partitions Mac OS X can not read. Open Disk Tools (Apple menu->Recent items->Disk tools) and format the FAT32-partition to Mac OS X extended (choose the partition in the left panel (not the disk, only the partition) and use the delete tab to name it and make it Mac OS X Extended (Journaled). Go to the Restore tab. Drag your Backup disk to the "From..." field and the newly made Mac OS Extended (HFS+) disk into the "To..." field and press the "restore" button. Quit Disk Tools when it is finished restoring. Eject the other partitions and disks in the Finder and disconnect the FireWire cable. Restart your MacBook and at the rEFInd window you will now find Mac OS X and Linux.

Then you need to install firmware for the isight camera and fan control. (See my blog post for an explanation of how to do this.)


How to configure routing table to pass traffic between network interfaces

Everything looks good.
192.168.0.20 is on your enp2s0 interface and 192.168.1.254 is on your enp3s0 interface. But you're telling your computer to go OUT of enp3s0 to reach 192.168.0.20 which it tries but fails as it's suppose to since it cannot get to 192.168.0.x from enp3s0.

You need to try the ping from another machine on the LAN. i.e. configure a box on you internal 192.168.1.0 network to go through gateway 192.168.1.254 and try to ping 192.168.0.20

Update:
Oh and this route makes no sense remove it:

192.168.1.0     192.168.0.20    255.255.255.0   UG    0      0        0 enp2s0


Ubuntu 13.10 wireshark crashes at start of capture with segfault unless ran as root

After attempting to run wireshark from terminal and collecting a log:

wireshark &> out.log

the log was filled with things like

(wireshark:6087): GLib-GObject-WARNING **: invalid unclassed pointer in cast to 'GtkScrollbar'

(wireshark:6087): GLib-GObject-WARNING **: invalid unclassed pointer in cast to 'GtkWidget'

.
.
.

Upon googling these I came across bug1 and bug2, and the solution posted there:

export LIBOVERLAY_SCROLLBAR=0
wireshark

got wireshark running for me.

....................................ASIDE....................................

Quite strange really, as I hate overlay scrollbars and have disabled them anyway, with the command:

gsettings set org.gnome.desktop.interface ubuntu-overlay-scrollbars false

and they don't appear on any of my other applications (e.g. firefox or the terminal), so strange that wireshark is snagging on them.

Also strange that root didn't have issues.

................................................................................


Cannot install Ubuntu 16.04 LTS on Asus ROG Laptop

NVIDIA graphics are glitchy with Ubuntu 15.10 and up. Some people don't have problems, while others get exactly what you're getting. Luckily, it's a pretty easy fix.

When the GRUB menu comes up, asking you what you want to do, highlight Try Ubuntu and press E. At the end of the line beginning with linux, enter nouveau.modeset=0. Press F10 to boot into the Live Session.

Once you install Ubuntu, you'll want to take a look here: Graphics issues after/while installing Ubuntu 16.04/16.10 with NVIDIA graphics


Stuck on boot "Faild to start network interface"

If you haven't installed any macchanger, you can remove /etc/network/if-pre-up.d/macchanger and then restart your network manager:

Edit

If your root filesystem is Read-only, first mount it in read-write mode:
sudo mount / -o remount,rw

Then:
sudo rm /etc/network/if-pre-up.d/macchanger -f
 sudo systemctl restart network


How to give a password to ubuntu user, which password recommendation does not pass?

Try setting the users password as root user i.e

sudo passwd user-name

I just tried it and set my password to "a"

adnan@adnan-ubuntu-vm:~$ sudo passwd adnan
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
adnan@adnan-ubuntu-vm:~$


19.10: There is no sound on Asus Zenbook UX534

Since when do you have this problem?
For me the problem with no sound started with the 5.3.0-41 kernel.
Booting with the older 5.3.0-40 kernel solves my problem.


From the wiki:

CRF with maximum bit rate
You can also also use a crf with a maximum bit rate by specifying both crf and maxrate settings, like

ffmpeg -i input -c:v libx264 -crf 20 -maxrate 400k -bufsize 1835k output.mp4

This will effectively "target" crf 20, but if the output exceeds 400kb/s, it will degrade to something less than crf 20 in that case.


apt install graphviz failing with segmentation fault

Reinstall package containing the libgvplugin_pango.so.6 and the graphviz package with
sudo rm /usr/lib/x86_64-linux-gnu/graphviz/config6a

sudo apt-get install --reinstall libgvc6 graphviz


dphys-swapfile will not calculate greater than 2GB swap file

The aborting execution upon calculation is LP#1788681 and already fixed in the current development branch Cosmic, but not yet in 18.04 Bionic. (I don't seem to be able to mark that bug as affecting a specific Ubuntu release so someone else needs to do that.)

It's caused by dc having become more picky over time and the correct fix is to replace all occurrences of p q (only show up in commands piped into dc) with just p.

Full patch is available in Debian's Gitlab.

Probably the easiest way to fix this locally on a Bionic is to install dphys-swapfile from Ubuntu Cosmic on Bionic. E.g. download the according binary package from Launchpad and then install it or upgrade to it using dpkg -i dphys-swapfile_20100506-5_all.deb with root permissions.

P.S.: No need to switch the script to bash.


In Ubuntu you can go to all settings and search for power in the search bar. You can change the sleep time from there.


Can I search by application type/usage/category instead of application name in Unity Application lens?

I figured out that when you search in the lens, your term will be used to search for an application or an application with the keyword in the comment. So, there's a way to change that.

Open terminal and run the following commands:

cd /usr/share/applications
ls

When you find the launcher of the application you want, run:

sudo gedit AvideMux.desktop

(Using AvideMux as an example)

In the window, find the line "Comment" and add the words "video editor", for example. This should make it so that your search should bring up your application of choice.


I suggest you look into http://winhelp2002.mvps.org/hosts.htm. I use and have adapted their suggested hosts file for my own use. If you wish to use it, please open a terminal and do:

wget http://winhelp2002.mvps.org/hosts.zip
unzip hosts.zip

Now, we will adapt the file somewhat to our use in Ubuntu:

gedit HOSTS

Remove entirely these lines:

127.0.0.1 localhost

::1 localhost #[IPv6]

Save and close the text editor.

Now, we'll back up your existing hosts file:

sudo cp /etc/hosts  /etc/hosts.bak

Now, we'll append the HOSTS file you just amended to your /etc/hosts file:

cat HOSTS | sudo tee -a /etc/hosts

You should be all set.


You could stop Display Manager using systemctl. In my case it's lightdm:

sudo systemctl stop lightdm

Then switch to other terminal: Ctrl+Alt+F3

After performing required actions, you could try to start it again by:

sudo systemctl start lightdm

All user's processes will be terminated.

To find out what display manager is used, run the next command:

cat /etc/X11/default-display-manager


How can I remove Ubuntu without affecting Windows so I don't have to choose an OS to boot at startup?

This question appeared in my 'dashboard' as active but I've just realised it's from over 5 years ago - it looked active because Community has marked it for being moved. But whilst I'm here anyway I'll add a little to it:

@phoibos offers decent advice to answer the question asked and then points in the direction of 'you don't need to get rid of Ubuntu to get the functionality asked for'.

Removing Ubuntu and getting Windows to re-write the bootloader afterwards is an awful lot more hassle than just changing a couple of lines in the grub file located in the /etc/default folder.

Open up a terminal and type sudo nano /etc/default/grub
Change GRUB_DEFAULT=0 to GRUB_DEFAULT=saved
Add GRUB_SAVEDEFAULT=true on a new line below it.

From there you can press Ctrl + o to save your changes ('Write Out'), enter to accept the filename 'grub' and then Ctrl + x to exit.

If you prefer you can just press Ctrl + x once you've made your changes, y to accept the offer to save your changes and then enter to accept the filename.

When you run sudo update-grub to update your new grub adjustments, then the last Operating System that you successfully booted will be the default option.

So if you usually end up running Windows, then when you switch on your machine it will be the option highlighted in the grub menu. If you don't choose something else then it'll get on with booting it when the timer runs out (or you press enter).

Using the same method, you can also change the GRUB_TIMEOUT=10 to just a few seconds if you prefer to get on with booting your usual choice more quickly.

Keeping another Operating System on your machine may turn out to be surprisingly useful if something unexpected happens to your main system.

(This assumes that you can spare 15 - 20 GB or so on your storage device, although some of the lighter distros take up even less space even with a bunch of useful programs installed).

Also, Community, don't worry about deleting/moving this answer if you'd prefer - I've saved a copy in case something similar is asked again ;)


Disable the repo Removing & Disabling Repositories


Menus and text boxes look graphically corrupted in 12.10

The thing I would do, is make sure my /home/"user name" directory is backed up!!!!

I usually install the system on a partition of 15+GB mounted at / and then have the rest for my /home partition.  That way if I do something funny (which I sometimes do for fun :) I can easily reinstall everything fresh without having to reconfigure anything.  As you may know all your config files are in your ~/ (otherwise known as /home/"user name") directory.

So, first back up your important stuff if your computer is having trouble.

If you reinstall and the problem persists you have a serious bug.  I would go with the LTS if that is the case.  You can generate a download script for all your current packages in synaptic package manager as well.  I find fresh installs go smoothly, whereas upgrades have always given my computers trouble (well... maybe not back in the hardy heron days....) Anyway these days I always download an ISO & boot it, and manually partition my computer to use the /home partition as my home partition (ext4... since brtfs isn't ready yet) and then I keep 1 or 2 partitions for an OS.  I would like Ubuntu to offer a separate /home partition as default as it can keep many problems at bay when reinstalling.
No matter what you do BACKUP your work if things are going awry


Typically I check to see if my proxy is working by finding a site that will tell me what my IP is (such as http://www.whatsmyip.org/).

If this displays the IP of your proxy (or a different IP than it shows if you're not using a proxy) then your proxy should be working.

You may also need to check setting specific to your web browser to be sure it's using the system settings for proxies.

You may also check to be sure websites you're trying to access aren't blocked on the DNS level.  If so you may need to manually specify a different DNS server.


Can I change my server's passwords server from a password manager?

I'm not aware of such a key manager or key manager plug-in. The reason, I believe, is that there's no real benefit from key changes that are so frequent that they become cumbersome to perform manually.

If you need secure remote access to your machines use SSH with public-key authentication. There is no known feasible attack against that method (if used carefully), so there's no need to change them frequently.


How can I install my Sims 3 expansion packs?

In short, no... but you might be able to play them using Wine... which you can learn more about here and also find there compatibility list...


You can cancel the installation or just kill USC. After that check if Calibre works. If not, try this command on terminal:

sudo dpkg --configure -a

This yields some output on the screen. If installation is corrupted you can see this easily. After that you can try to reinstall Calibre or purge and install it again.


Ubuntu frozen on boot screen; boot repair fails due to X11 and gtk

This may worK:

sudo dpkg-reconfigure lightdm (you said that you can log on.)

Then choose "Ok", and select a display manager from a list. That can be lightdm, gdm, ... (if you have installed it, for example, by sudo apt-get install gdm)


After updates Ubuntu works very slow etc

Sounds like your main issue (so far) is realistically just with Firefox.

Have you tried to uninstall/reinstall Firefox yet?

sudo apt-get remove firefox
sudo apt-get install firefox

Try that, and let us know if that fixes Firefox.  I wouldn't revert basic OS updates as of yet, as a newer user to Ubuntu.


Can't start a Unity session from an upgraded account but I can from a new one

try ctrl-alt-F1 then login with your regular account. Then

sudo mv ~/.Xauthority ~/.Xauthority.old

according to this bug

https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/871667


How to bypass "Try it / Install" screen when booting from USB Live Session? (without installing in the USB)

This guide was made for Ubuntu (Gnome). It works for Kubuntu (KDE) too, with a few exceptions

I've been able to get the Live CD boot straight into a Live session without timeout or fancy menu, optionally with a language pack installed.

Live USB (16.04)

Mount the USB with Ubuntu installed in it
Backup the file syslinux/syslinux.cfg. We will modify it so we need
to replace it back if something goes wrong.
Open the following files under syslinux directory: syslinux.cfg and
txt.cfg
Delete (or comment) everything in syslinux.cfg.
The txt.cfg file has the default GRUB menu entries. Copy the live
one to syslinux.cfg:

default live
label live
menu label ^Try Ubuntu without installing
kernel /casper/vmlinuz.efi
append file=/cdrom/preseed/ubuntu.seed boot=casper cdrom-detect/try-usb=true persistent noprompt floppy.allowed_drive_mask=0 ignore_uuid initrd=/casper/initrd.lz quiet splash --

You can add any specific kernel parameters needed for your device in
the append line.
Save isolinux.cfg and boot your system using the USB. It will boot
straight to the desktop now.

Live USB (13.10)

Mount the USB with Ubuntu installed in it
Backup the file isolinux/isolinux.cfg. We will modify it so we need
to replace it back if something goes wrong.
Open the following files under isolinux directory: isolinux.cfg and
txt.cfg
Delete everything in isolinux.cfg.
The txt.cfg file has the default GRUB menu entries. Copy the live
one to isolinux.cfg:

default live
label live
menu label ^Try Ubuntu without installing
kernel /casper/vmlinuz.efi
append file=/cdrom/preseed/ubuntu.seed boot=casper cdrom-detect/try-usb=true persistent noprompt floppy.allowed_drive_mask=0 ignore_uuid initrd=/casper/initrd.lz quiet splash --

You can add any specific kernel parameters needed for your device in
the append line.
Save isolinux.cfg and boot your system using the USB. It will boot
straight to the desktop now.

[source]

Live USB (11.04)

Go to the root folder of your Live USB
Enter the syslinux directory
Make the syslinux.cfg file writeable
Replace the contents of the file syslinux.cfg with:

default live
label live
  say Booting an Ubuntu Live session...
  kernel /casper/vmlinuz
  append  file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash noprompt --

Optional: localize the system (see below)

Live CD

If you've a Live CD in your CD drive, mount it. Otherwise, if you've an ISO file available, mount it on /media/cdrom by running the next command in a terminal (replace the name of the .iso file accordingly):

sudo mount -o loop,ro ubuntu-11.04-desktop-amd64.iso /media/cdrom

Create a temporary directory in which the CD contents can be stored, say ~/live-cd (mkdir ~/live-cd)
Copy the contents of the CD to the folder ~/live-cd/iso (cp -r /media/cdrom ~/live-cd/iso)
Since the Live CD is not needed anymore, it can be unmounted (sudo umount /media/cdrom)
Open the ~/live-cd/iso folder (cd ~/live-cd/iso)
Enter the isolinux directory (cd isolinux)
Make the isolinux.cfg file writable (chmod u+w isolinux.cfg)
Replace the contents of the file isolinux.cfg with:

default live
label live
  say Booting an Ubuntu Live session...
  kernel /casper/vmlinuz
  append  file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --

Optional: localize the system (see below)
Open a terminal and run:

cd ~/live-cd
chmod u+w iso/isolinux/isolinux.bin
mkisofs -r -V "Ubuntu Live session" -cache-inodes -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -o ubuntu-11.04-live-amd64.iso iso

The new iso will be available at ~/live-cd/ubuntu-11.04-live-amd64.iso. To save space, the ~/live-cd/iso directory can be removed. (rm -rf ~/live-cd/iso)
Now burn the ubuntu-11.04-live-amd64.iso file on a CD if needed.

Localize Ubuntu (translations)

If you want the system in the languages English, Spanish, Portuguese, Xhosa or Simplified Chinese, you've just to add the locale= boot option with en, es, pt, xh or zh to the append line as in:

... quiet splash locale=pt --

Otherwise, if you do not want to modify the file containing the root file system (filesystem.squashfs) and do not mind hacking around, continue reading.

Open a terminal and navigate to the ~/live-cd/iso directory and put the code from http://pastebin.com/VTdt9WFZ in a file (name it install-locale) and run it.

This script mounts the filesystem.squashfs, retrieves version information of the language packs from it, downloads the packages and put those in the directory locale-hack. Next, a script is created that installs the language packages on boot time. To make that work, the script also modifies the syslinux.cfg or isolinux.cfg file to apply these changes.

You'll be asked for a locale, enter something like nl or de. The script is not that clever to understand things like Dutch or German. Afterwards, the file can be removed

The terminal commands that should be executed:

cd ~/live-cd/iso
wget http://pastebin.com/raw.php?i=VTdt9WFZ -O install-locale
bash install-locale
rm install-locale

Note that adding language pack can cause the generated .iso file to be bigger than 700MB which won't fit on a CD. For virtual machines however, it suffices. This hack has as a side-effect that Plymouth does not work (i.e. you do not get a fancy boot screen), but at least the system is translated when logging in. Otherwise, you had to install language-pack-gnome-* manually.

References

Syslinux example
Ubuntu Help on custominizing a disk / burning it


What do the following command in detail du -s * | sort -nr > $HOME/space_report.txt?

The first command shows the size of all the individual files and directories in your current directory (most likely your home directory or ~/).

Next, sort -nr sorts the results by number and then reverses those results to show the largest files or directories first, down to the smallest ones and prints the results to a file named space_report.txt in your home directory.

To view the results, you can run one of the following commands:

cat ~/space_report.txt

or

less ~/space_report.txt

Personally, I would use this instead because it prints the file size in a human readable form:

du -hsx * | sort -rh > $HOME/space_report.txt

Again, to view the file:

less ~/space_report.txt

or

less ~/space_report.txt

If you don't want to print to a file, you could just run this instead:

du -hsx * | sort -rh

To figure this out on your own, all you have to do is type:

du --help

and look for the -s flag to see what it is for.

Then, do the same for sort:

sort --help

and look for the -n flag and the -r flag.

For more information, you can run the following:

man du

or

man -Hfirefox du

and

man sort

or

man -Hfirefox sort


I accidentley deleted my mp3 files on my mp3 device

As long as you did not physically overwrite your memory on your mp3-player you can try to harvest your files using PhotoRec from the Testdisk Suite .

Read this guide from the makers of TestDisk/PhotoRec for step by step procedures.

Note that folders and filenames will not be recovered by this. But you can later rename them using the mp3-tags within the files.


How to install Red5 on Ubuntu with my vps company OVH

To install Red5 run

sudo apt-get install red5-server

All needed things (other packages like Java and so on) will be installed automatically.


12.10 Login Screen Skipped, Just begins session

seem to have fixed it by constantly typing

sudo gpasswd -d username nopasswdlogin

although it never reprted a sucess the problem is fixed:D


I have two harddrives, there's windows 7 installed on the main one, and ubuntu on the other one

My thought is that it is just automatically looking on the windows disk for an os as it is set to boot from it by default. What you probably need to do to avoid getting into the complexities of chain loading is press f12 (or whatever it is on your computer to change boot devices) and select the name of the ubuntu hard disk when you want to boot into it.


How to convert MKV to MP4 using ffmpeg keeping all video, audio tracks and subtitles?

Use -map advanced option. See manpages (man ffmpeg) but basically use -map 0
Excerpt from manpage:
For example, to map ALL streams from the first input file to output
ffmpeg -i INPUT -map 0 output


How do I configure the various services available on Ubuntu Server?

This looks like is too vast to attempt to answer in AskUbuntu.com as it differs for each case asked for. However let me attempt to give some overview and  on  what needs to be done and I given a link to "Ubuntu 12.04 server guide" for referring to details on "How To". If any of those are confusing, please post diffe

For websites, you need to configure apache.
For  email, you need to some thing like postfix configuration (or other email servers you like a different once)
To configure  services, you need to review update-rc.d command to change the current default startup and shutdown commands.

For a detailed how to on each of these, please refer to 12.04 server guide here


mpif.h not found error [install openmpi]

To include a C-style header file in a Fortran program, you need to use a C-style pre-processor directive

#include <mpif.h>

rather than a native Fortran include statement, and then tell gfortran to run the pre-processor by adding the -cpp command-line switch (or change the source file suffix to upper-case F90 which causes the pre-processor to be run by default). See for example

including a c/c++ header file in fortran subroutines

However including mpif.h is apparently deprecated, and instead you should probably use the MPI module, and compile your program using mpif90 instead of invoking gfortran directly.

Fortran Support Through the mpif.h Include File

Ex.

$ cat ubuntu.f90
program hello
use mpi
integer rank, size, ierror, tag, status(MPI_STATUS_SIZE)

call MPI_INIT(ierror)
call MPI_COMM_SIZE(MPI_COMM_WORLD, size, ierror)
call MPI_COMM_RANK(MPI_COMM_WORLD, rank, ierror)
print*, 'node', rank, ': Hello world'
call MPI_FINALIZE(ierror)
end

$ mpif90 ubuntu.f90

$ ./a.out
 node           0 : Hello world

FWIW, your changes to PATH and LD_LIBRAY_PATH likely have no effect since you have installed openmpi into system directories using apt


How to open files from other machine running ubuntu

You can always try this:

On the folder you want to share, right click :

Check the Share this button

Say yes to install additional software
Finally, click on Create Share to share the folder; the folder’s icon will look like the following:

Now everything is done. To access the shared folder through other computers of the network, just open up Nautilus, in the left sidebar click on Browse Network then choose the name of the computer in which the folder is shared and you will see it.

Source


creating postfix email user without shell access

I can't test it at the moment however, I believe nologin will work for you.

sudo usermod -s /usr/sbin/nologin username

It will only affect the users shell access, by instead of setting a default shell it will politely tell them to go away.

Additionally, postfix.admin may be the tool you're looking for to manage your users with a web interface.

http://postfixadmin.sourceforge.net/


If I have understood your question, the background image that you think is of the GNOME session is only the background image of the GDM (the graphical login) that will be changed when the desktop envinronment is ready.
So if at the GDM login you choose the XFCE session don't worry : GNOME hasn't started.


unattended-upgrades not running, /etc/cron.daily/apt missing

Try

apt-get install cron-apt

for this file


Your comment suggests that you are running Unity 2D and not Unity, so Compiz shortcuts like Super + W won't do a thing.


I suggest you read the Documentation for Puppet it offers lots of different features. And I would probably sling this on server fault instead on ask Ubuntu, might get a little better response on there.

http://docs.puppetlabs.com/

You will need to learn the syntax for Puppet

service { "apache2":
  ensure => "running",
}

Above is an example of code to check that the apache2 service is running. Its really worth reading through the docs though because they are very useful. Also below is a link to a puppet cookbook of little snippets of code. Again very good and can be used to hack together your own stuff.

Thanks
William

http://www.puppetcookbook.com/


take output from the mysql and stored into excel

Move to the directory where you would later like to have your CSV file saved. Then run

mysql -u root -ppass123 -e "USE test_db; SELECT * INTO OUTFILE 'testtable.csv' FROM test_table;"

Please note that "SELECT *" selects all columns, while you listed all of them. If you want to select only certain columns, you will need to replace * by the columns names again, separated by commas.

It will produce a file called testtable.csv in this directory, that you can open with MS Excel or LibreOffice Calc.

Look into the MySQL documentation for SELECT ... INTO OUTFILE here for further info:
http://dev.mysql.com/doc/refman/5.7/en/select-into.html


Why script with /bin/bash is working, with /bin/sh not?

It's because Bash behaves differently when $0 is sh.

From Bash's behaviour    [Bash Hackers Wiki]:

  SH mode

   When Bash starts in SH compatiblity mode, it tries to mimic the
  startup behaviour of historical versions of sh as closely
  as possible, while conforming to the POSIX® standard as well. The
  profile files read are /etc/profile and
  ~/.profile, if it's a login shell.

   If it's not a login shell, the environment variable ENV is evaluated and the resulting
  filename is taken as name of the startup file.

  After the startup files are read, Bash enters the POSIX(r)
  compatiblity mode (for running, not for
  starting!).

   Bash starts in sh compatiblity
  mode when:   the base filename in
  argv[0] is sh (Attention dear uber-clever
  Linux users… /bin/sh may be linked to
  /bin/bash, but that doesn't mean it acts like
  /bin/bash)

More information can be found at the Bash Reference Manual: Bash POSIX Mode, specifically:

  Process substitution is not available.

which is why your sh script is failing, as the <(..) syntax is using process substitution.


What does "ldconfig deferred processing now taking place" mean?

ldconfig creates the necessary links and cache to the most recent shared libraries found in the directories specified on the command line, in the file /etc/ld.so.conf, and in the trusted directories (/lib and /usr/lib). The cache is used by the run-time linker, ld.so or ld-linux.so. ldconfig checks the header and filenames of the libraries it encounters when determining which versions should have their links updated.

ldconfig will attempt to deduce the type of ELF libs (i.e., libc5 or libc6/glibc) based on what C libs, if any, the library was linked against.

http://linux.die.net/man/8/ldconfig


Mavericks Screen Sharing resolution - Remmina VNC client

Vinagre (available in the Ubuntu repositories, goes with the builtin VNC server Vino) supports scaling the screen down. However, even when scaled, VNC works at the host's real resolution; so you're still sending quite a lot of data over the network in this case.


I'd suggest that you keep things as simple as possible. You may have a Windows recovery partition created by the manufacturer, you'll have a Windows ntfs partition, and you will need a partition for an ext4 partition for Ubuntu. A swap partition a couple times as big as your main memory isn't a bad idea.

The more partitions you have the more likely one will be too small and you will have to resize later, needing to do the work of backing everything up before you do--that's why I suggest you only have the minimum number needed and use the large disk size to be rather generous with their sizes.

One commom approach is to add another directory for /home so that you can do a fresh install of a new Ubuntu version after release without having to move your data.

Don't create four primary partitions--four primary partitions don't allow you to add any logical partitions and there can only be four primary partitons. If you want four partitions make the fourth a logical partition in an extended partition. It's a big pain to convert a primary partition to an logical partition.

Bigger disks give you more flexibility. Other than that the particular hard drive you have probably doesn't matter much in terms of partitioning (exceptions would include RAID arrays or other special storage used in large servers).

Many years ago files were placed near each other manually and one cared about cylinder sizes, etc. That's not current practice. The firmware in the hard drive hides the actual disk geometry from the rest of the system, writes these days are simply to the sector number n. The firmware will even move data around as sectors go bad.

As I recall the EXT file systems will try to co-locate the files in a particular directory in the same cluster, to try to reduce disk arm movement. With current disk technology there's quite a bit of data per actual cylinder. Also with current memory sizes modern kernels do aggressive data caching to reduce subsequent I/O to nearby data in open files, removing motivation for worrying about file placement.


How to get info on my current GRUB / boot configuration?

To view your /boot/grub/grub/cfg file, you might use the following command,

less /boot/grub/grub.cfg

Press your up or down arrow keys to scroll up and down the file, use your 'q' key to quit and return to your regular terminal prompt.
The grub-mkconfig program runs other scripts and programs such as grub-mkdevice.map and grub-probe and then generates a new grub.cfg file. It also reads files in /etc/default/grub and the /etc/grub.d/debian theme file to tell it what to do. Those are the files we can edit or create for ourselves to change our GRUB settings. I'll show you more about that later.

Below here is an example of a grub.cfg for a new Ubuntu installation in a computer that already has one other Ubuntu installation dual booting with Windows XP.
I have highlighted the commented lines in yellow to draw your attention to them.
You should notice that they each mark the beginning and ending of their own section of the grub.cfg and they appear in numerical sequence starting from the /etc/grub.d/00_header at the top.
The last section of this file is the /etc/grub.d/40_custom area at the bottom of the grub.cfg file.
Each of these sections of the grub.cfg file are controlled by the scripts with the same names, and those are the ones we edit to make changes to our grub.cfg.
The changes will come into effect right after we run 'sudo grub-mkconfig -o /boot/grub/grub.cfg' to write the new grub.cfg file.


Usually, the best is to partition the drive during install, or, in your case, leave the partitions as they are and install Ubuntu on the partion where windows is (replace it).

By default, Ubuntu uses the whole disk for installation. In your case you should have done the installation steps untill you can choose "installation type" and choose "something else" there. Then remove the windows partition and create a swap partition of, let's say 1GB and an ext4 partition to install the system on (mountpoint /).

To make the existing data partition available in the newly installed system, select it (in the same window) and choose "Change" (next to +-); keep the same file system as it already is and give it mountpoint /data or something you like. Do NOT format the partition! That way it would have been as you planned.

In this situation you can choose: do a reinstall and a repartitioning, or just copy your existing data to /home/"yourname". You could of course resize the partition to be able to create your data partition, but it is more "clean" to reinstall; you just installed Ubuntu and probably did not do too much work afterwards. All should take no more than just 30 minutes.

here are a few links to screenshots:

choose "something else"

remove existing partitions:

create new partitions (in your case somthing like 1x 20GB for Ubuntu, 2gb for swap, the rest for /data (the picture shows adding the swap partition)

Start with the system partition, mountpoint /, then the data partition, /data, and finish with the swap partition. If you do it like that, Ubuntu will set the "type of the new partition" automatically correct.

and ready to install:
`


How to prevent files from being removed when I remove them from a linked directory?

That's the default and correct behavior.

As you know, /target is just a symbolic link to /folder.  When you go inside /target, the files you see are actually living inside /folder. These are actual files and not symbolic links. So when you delete them, you are deleting the actual files living in /folder.

In other words, creating a symlink to a directory does not creates a link for each file/directory inside that directory.

What to do?

Now we know that we have to create a symbolic link for each and every file in "folder". To do that use cp:

cp -rs /folder /target

or as mentioned in the comments to get hard links:

cp -rl /folder /target

You can also use lnddir.


You should disable power management. Open terminal by ctrl+alt+t and run following commands one by one

    sudo ifconfig wlan0 down
    sudo iwconfig wlan0 power off
    sudo ifconfig wlan0 up

If it works, make it permanent by putting it into script or through pm-utils.

If that didn't solve your problem than disable n

If you have intel type of wireless card, you might want to try disabling n-wireless.

Hope it helps.


Exact duplicate of my error trying to overwrite '*', which is also in package faenza-icon-theme 0.8

Follow the same steps and you should have no issue.

I sent an email to the package manager of Faenza icons about this but received no answer...


You should first downgrade it. Then try again to jailbreak it..
Good luck..


Why is my bash script getting "Killed"? How do I prevent that?

ulimit -t 1 limits the script's CPU time to 1 second. When the script has consumed all its CPU time it gets killed.

To limit the CPU time of just one command in your script you can use parentheses to start it in a subshell with its own limit, e.g.

(ulimit -t 1; LD_PRELOAD=../../EasySandbox/EasySandbox.so ./a.out < $testin)


Moving grub from C: to D:, was previously working

It appears that you have two HDD's, on one HDD Windows7 is installed and on the other HDD
Ubuntu is installed. It also appears that your system is set up in legacy-mode.
On the drive where Windows is installed you reinstalled Windows boot-loader in the MBR of the drive already.
Now you need to install Grub to the MBR of the drive, where Ubuntu is installed.

To do that you have to boot from a live USB, choose Try Ubuntu, then open a terminal and run the following commands:

sudo mount /dev/sdb1 /mnt
for i in /sys /proc /run /dev; do sudo mount --bind "$i" "/mnt$i"; done
sudo chroot /mnt
sudo grub-install /dev/sdb
sudo update-grub
exit
sudo reboot

Note that in this commands sdb1 means the partition, where Ubuntu is installed
and sdb means the HDD where Ubuntu is installed. You have to examine your system and change these values accordingly.

After Grub has been installed, boot to BIOS-setup and change the boot-order
to the Ubuntu-drive in the first place and the Windows-drive in the second place.

Related:
How can I repair grub? (How to get Ubuntu back after installing Windows?)

Edit

The boot-info-summary looks good so far, found a small bug in line 416 (this is related to /etc/fstab and sdb6. Compare with line 516).
Fact is, that Grub is now installed in the MBR of the second drive, and when we boot to this drive, Grub should be booted (even if Grub is  not correctly configured or, for example, the Ubuntu-partition was deleted), in the worst case it should boot to Grub-rescue.

I think, booting to the MBR of a HDD on the slot the drive is connected to is just not supported by your BIOS. I've been confronted with this on several laptops. Check manual of your hardware if you can find any information. If this is the case, you can't achieve the bootloader-configuration you described, you will need the boot-loader in the MBR of sda and this boot-loader needs to be able to boot both Os's. This is normally Grub.

IF you keep your current partition-layout and install Grub on the first drive (sda) you will boot to Grub-rescue as soon as you removed the second drive because Grub can't find it's configuration-files which are stored on the removed drive. You would need an external DVD which you connect via USB if you need to work with DVD.

The other way around is to change the partition-layout and install both OS's on the first drive (sda), using the second drive as a pure data-storage. This way you are independent from the second drive during boot, you could replace the second drive with your DVD.

However, you can configure Grub in many ways (default-boot, hidden menu,...). The configuration is stored in /etc/default/grub and you can edit this file with root-privileges (i.g. sudo nano /etc/default/grub).
Look for the lines with GRUB_DEFAULT=
GRUB_TIMEOUT= and change the values for this entries to set the default menu-entry to boot and/or hide the Grub-menu (`GRUB_TIMEOUT=0). See detailed information in the Grub Manual.


Problem upgrading Kubuntu 17.10 to 18.04

"Upgrades from 16.04 LTS will not be enabled until a few days after the 18.04.1 release expected in late July."

I think the option is not enabled yet


Missing dependency packages when installing skype-call-recorder

Using dpkg -i to install a .deb package does not resolve dependencies and install them as well. You will have to install them by hand with sudo apt-get install libqtgui4 for example, or you will need to use another tool which does resolve the dependencies, such as running software-center skype-call-recorder-ubuntu_0.8_i386.deb which should also resolve the dependencies and pull in the necessary packages.


puTTy fatal error (no supported authentification method available)

Welcome to Linux :-)
Firstly make sure you always download the keys when the AWS console offers - there is no chance to get them again! :-)
Once you have the private key, from the Linux command line you can connect directly using the Linux ssh client. Don't forget the username! The default on ec2 is "ec2-user"
ssh -i MyKey.pem ec2-user@a.b.c.d

For Putty on Linux, you need to use PuttyGen to convert the key:
puttygen MyKey.pem -o MyKey.ppk

Then in Putty create your session for the host you wish to connect to. I usually create the hostname as "ec2-user@IPAddress". Then in the Connection->SSH->Auth menu load your key for that session. Hit connect it will log you in to the EC2 instance.


Is it possible to start multiple applications with a single custom keyboard shortcut in "Keyboard" settings in Xubuntu?

Command lists and background invocation is actually the right shell feature to do here. If the shell script works for you there are no considerable drawbacks in this context.


Starting remote script/terminal based programs through ssh gives error (Error opening terminal: unknown.)

You would have to use the -t flag.

Examples:

 ssh -t me@server 'nano my_file.txt'
 ssh -t me@server 'open_nano.sh'

Explanation from man ssh:

 -t      Force pseudo-tty allocation.  This can be used to execute arbi‐
         trary screen-based programs on a remote machine, which can be
         very useful, e.g. when implementing menu services.  Multiple -t
         options force tty allocation, even if ssh has no local tty.


Emerald hasn't really been maintained for quite a while, and no one has developed a usable replacement as yet.

You may be able to use it on 11.04 on any Desktop (I have not tested with unity btw), but don't expect anything special or stable. In essence emerald is dead.


Go to additional drivers tab in software & updates.
Check for any drivers. If there are allow them or install them.

Try these sites also:

https://help.ubuntu.com/community/BinaryDriverHowto/AMD

http://ubuntuforums.org/showthread.php?t=1203437


How to set up SAMBA / CUPS print server?

There is a Ubuntu based equivalent -if not better called Zentyal and can be either installed as an appliance or on top of a Ubuntu installation (Zentyal-Samba and Zentyal-Printers)

More details Here


Kubuntu 17.04 Not installing some Apps from PPA

You have a bad (I don't know what else to call it) PPA in your system

W: The repository 'http://ppa.launchpad.net/docky-core/stable/ubuntu zesty Release' does not have a Release file.

You should remove that PPA and then try again.

I can help you if you give the list of PPA's that you have by doing

ls /etc/apt/sources.list.d/


Default grub menu entry can be switched using GRUB_DEFAULT in /etc/default/grub file.
If your kernel 3.2 entry is 7th in the list - the easiest way to set to default would be making following change in /etc/default/grub:

GRUB_DEFAULT=7

And then executing sudo update-grub2 to update grub configuration.


Getting Errors while installing php on ubuntu16.04

Run the following commands:

sudo apt-get update
sudo apt-get install --reinstall php7.0-common

If that doesn't work, run the following commands:

mkdir PHP
cd PHP
apt-get download php7.0-common
ar -xvf *
tar -xvf dat*
sudo mv ./usr/lib/php/7.0/php.ini-production /usr/lib/php/7.0/php.ini-production
sudo apt-get -f install


If you're running Ubuntu 12.04 or 12.10, add the following ppa:

sudo add-apt-repository ppa:canonical-qt5-edgers/qt5-proper && sudo add-apt-repository ppa:ubuntu-sdk-team/ppa && sudo apt-get update

Or if you're running Ubuntu 13.04

sudo add-apt-repository ppa:ubuntu-sdk-team/ppa && sudo apt-get update

And then run the following command:

sudo apt-get install ubuntu-sdk


Search, with
find $HOME -not -user $USER  if some files are not belong to your user. Give them back to your user with

sudo chown -R $USER:$USER /path/to/file

Log out and login again.

The next step will revert your attitude from your desktop-session.

mv $HOME/.dconf $HOME/.dconf.bak

and the same for

mv $HOME/.gconf $HOME/.gconf.bak

logout and login again.


Without Airport Utility you will no longer be able to change the configuration on the Airport Express, but it will keep working with its current configuration. It doesn't matter at all to the functionality of the Airport Express whether you're running Linux or OS X, except when you want to change its config.


Yes. Use the Ondrej repo.  It's more up to date than the default 18.04 Ubuntu repo.  However, it is unfortunately lagging a bit behind Remi.  I wish Remi was available on Debian/Ubuntu, but alas.

https://launchpad.net/~ondrej/+archive/ubuntu/php/


How can I select a region in an image file, and hide the region?

Open the image in GIMP. Click Tools > Selection Tools > Rectangle Select Tool. Outline the area you wish to blur.

Next, click Tools > Paint Tools > Smudge. Use the mouse to smudge the selected area as desired.

Next, click Select > None. Next click File > Export As... Export the file as any file format you wish. Exit GIMP.


How can I change the tooltip color or font in Ambiance?

Goto System -> Preferences -> Appearance. In Themes select the Ambiance theme and hit the Customize... button.

In the just popped up Customize Theme window select the Colors tab.

Now edit the colors to your desired value. The Tooltips colors are highlighted on the screenshot.

Note: I'm using 10.10 but it should be similar on 10.04


The command you ran contained –c, which is an en-dash followed by a c. Although option arguments like -c are often informally pronounced "dash c" they must actually begin with an ASCII hyphen character. This is the same as the ASCII minus character (one name for this character is "hyphen-minus") but different from other Unicode dash characters like the en dash and em dash.

Commands don't give any special meaning to those dash characters, so while a -c argument specifies the short option c, a –c argument does not specify any option at all. You were actually running usermod with three non-option arguments, which is not one of the syntaxes it accepts, so it printed its help message.

The reason people end up typing en dashes instead of hyphens in commands is--well, nobody does that. Instead, some websites convert hyphens to en dashes. So when a command is copied from a page of such a website and pasted into a terminal, it wrongly contains an en dash instead of a hyphen. This could also happen if one used a program like LibreOffice to store a list of commands (and didn't turn off autoformatting).

Similar problems that often arise in practice from such mangled text include the insertion of extra spaces near punctuation (very bad in rm -r commands!), replacement of straight quotes with curly quotes, and the disappearance of text between a < character and a matching > character.

The command you meant to run, sudo usermod -c "Richard Tracy" dtracy, works fine.


A few things to check:

Verify that MAAS has the images you want to deploy in terms of Ubuntu releases and architecture.
Verify that your VM has a big enough disk for an Ubuntu installation (say, give it 10G)
Verify in MAAS that the node (VM) hardware is correct, i.e., that MAAS discovered the hardware correctly specially regarding the disk.
I don't remember if virt-io for disks is supported, so if you have that in your VM, try switching to SCSI or SATA (and recommission or even re-enlist so the new hardware is detected).
Check in the MAAS server logs if there is something fishy (/var/log/maas/*.log) during the boot. Maybe it's not finding the right image and that's the right failure.

If you change the hardware of the VM, don't forget to recommission, or even re-enlist if you suspect it wasn't updated in MAAS.

Other than that, you will need to supply some logs or screenshots.

Hope this helps.


Can I print to an Epson Expression XP-102?

I have had trouble too. If you go to the link below and download one of the drivers at the bottom of the page marked packages (I used the top one of the six), this gets the printer going. I am yet to get the scanner going but will let you know if I suss this out.

http://avasys.jp/eng/linux_driver/download/lsb/epson-inkjet/escpr/

Hope this helps,

Miles


I think you're confusing technologies here.

NVIDIA Optimus is the codename for the dual graphics card split enjoyed by a wide variety of "gaming" laptops with "dedicated" graphics. It has nothing to do with any form of software, it's merely a type of hardware setup.

Thereby, NVIDIA Prime is NVIDIA's solution to implementing Optimus usability on Linux. That being said, NVIDIA Prime is closed-source. It also has an annoying tendency to drain laptop batteries, as the discrete card usually stays enabled due to the lack of per-application switching found on Windows.

The open-source software community attempted to fix this with the creation of the Bumblebee project. Instead of using the always-on or always-off mode of Prime, Bumblebee created a utility called optirun that allows you to specify whether a program should be loaded with the discrete graphics card or not. However, reports of Bumblebee's performance are mixed at best, and have been known to be relatively buggy.

It would ideally be better to try Prime and Bumblebee (you can switch between them rather easily) and just decide which you like more (which gives you better performance, a longer battery life, etc.).


Brighness and sound problems on an Acer Aspire 4750G

I too have the Acer Aspire 4750G, however I use Linux Mint 11, though it is based on Ubuntu 11.04. I too also can't adjust brightness, however I was able to fix the plug-in earphones to work, or the headphone jack. The way I was able to fix it was that in the BIOS, I changed the graphics card from switchable to integrated, and all of a sudden the headphone jack started working. But if you want to play games in Windows, you have to switch the graphics card from integrated to switchable. I'm not sure why changing the graphics card settings affected the headphone jack. If sound doesn't work when you changed it, go to sound preferences and in hardware make sure Analogue Stereo Duplex is selected and in output select Analogue Speakers.

I'm not sure why changing graphic card settings fixed my headphone jack, but it might be because the Intel chip controls the headphone jack and when you use switchable, and since nVidia Optimus is not supported officially in Linux, that some aspects of the Intel chip like sound cannot be used. Hope this fixes it!.


If you want these effects, you would need to install compiz, but I don't know if it would work with Unity installed.


How to prevent computer from overheating

This isn't an answer, because I don't have the ability to comment yet, but have you checked your BIOS for some shutdown / power state / suspend parameter that Windows might be overriding but Linux isn't? It's weird how it shuts down at 64 degrees, which is nothing at all temperature wise. Try a different Live distro and hammer it with a benchmarking tool. That should hopefully give you some clues.


How to remove TuxCut app from Ubuntu 12.04

The version you had earlier also comes with English. Run tuxcut as it was(in Arabic), select your interface. So far everything would still be in Arabic. Now you should see a menu bar on top. It's above everything and has four drop down buttons aligned towards the right. Click on the third one from the right. It'll drop down to give you exactly one expandable button. Clicking on that will give you two options, one of which will already be checked. That one's for Arabic. And you guessed it, the other one's for English. Changes won't take effect till you restart tuxcut.

As for the errors. Using dpkg will result in the errors you are getting. Uninstall tuxcut using sudo apt-get remove tuxcut. Now re-install using dpkg the same way you were trying. It should work.


I see only 511mb volume from another disk with linux

The Ubuntu installer normally uses extended partitions so the filesystem is likely to be on the device sdb5.

You can get a list of all the block devices connected to your system with the command lsblk

The install uses LVM to manage the disks, you will need to start up the LVM subsystem. To do this do the following:

Find LVM volume groups, in this example one called storage with a volume called working inside.

sudo vgscan
Reading all physical volumes.  This may take a while...
Found volume group "storage" using metadata type lvm2

Next start the volume group up

sudo vgchange -a y storage
1 logical volume(s) in volume group "storage" now active

List the logical volumes within the new volume group

sudo lvs storage
LV      VG      Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
working storage -wi-ao---- 80.00g

Finally mount the volume:

sudo mount /dev/storage/working /mountpoint

Note if you are using a GUI desktop then the devices might appear as storage devices after you have started the LVM volume group up.


Ubuntu 20.04 unable to connect to the internet

I have solved the issue. I reinstalled Ubuntu 20.04 to my hard drive without checking the "install 3rd party drivers" at the boot menu. This installs a driver for my Wifi module which I then use to install the other modules needed (such as gcc and make) before installing r8125.
I can now use both Wifi and Ethernet connections.


Add the Official Graphic Cards PPA

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt-get update

Check which Nvidia Driver Version is the latest: Go to https://www.geforce.com/drivers and pick your GPU, check which one is the non-beta. Today the version is 390.
Leave the X server: Press Ctrl+Alt+F1 it should give you a black screen asking you to log in. After logging in, shut down the x-server with

sudo service lightdm stop

Install your Nvidia Driver

sudo apt-get install nvidia-390

Reboot your PC

sudo reboot


How to remove unity upper panel in my customizes ubuntu os

Simple answer: You cannot move the panel from the top to the bottom using the default Unity desktop.

Detailed answer: Unity Desktop(and Gnome Shell) is made to be simple and look the same on every computer. If you want something that is more customisable, you should try something else like KDE, XFCE, or the gnome2 which you can find in Ubuntu Sofwtare Center by seraching for gnome-fallback.


reaper.conf configuraton of reaper generate fault

I solved this by running:

sudo apt-get install make automake build-essential libcurl4-openssl-dev

Let me know if it helped.


How to set wlan higher prioriy than ethernet in ubuntu?

Open terminal and start nm-connection-editor, open your wireless connection profile, then edit the following highlighted field, enable it, and set it to 1.


Installing Nvidia , Cuda , Tensorflow in Genome ubuntu 16.04

First of all you open a terminal. The usual shortcut is ctrl+alt+T on ubuntu. If gnome doesn't have this shortcut, press alt+f2 and on the little window that opens write

gnome-terminal

Once inside the terminal write:

sudo apt-get install nvidia-current

Enter your password when prompted and if asked [Y/N] type y and press enter.

After that restart your PC.
You can also restart from the terminal with the command:

reboot

That's as far as my knowledge goes.I don't know about the rest you want to install. Google them and you will probably find answers, or wait for someone to respond.


Keyboard shortcut to open an application in new workspace in Gnome Shell 3.2

It doesn't seem possible, unless someone writes an extension for it.

According to the GnomeShell Cheat Sheet the closest you can get to this functionality is to launch the application, then use Ctrl+Alt+Shift+Up/Down to move it to another workspace.


What happened to the new icon theme for 12.04?

The new Icon Theme is yet to be released for Ubuntu 12.04


Print output of code in the middle of the screen

Try the script below. It will detect the size of the terminal for every input word so will even dynamically update if you resize the terminal while it's running.

 #!/usr/bin/env bash

## Change the input file to have one word per line
tr ' ' '\n' < "$1" |
## Read each word
while read word
do
    ## Get the terminal's dimensions
    height=$(tput lines)
    width=$(tput cols)
    ## Clear the terminal
    clear

    ## Set the cursor to the middle of the terminal
    tput cup "$((height/2))" "$((width/2))"

    ## Print the word. I add a newline just to avoid the blinking cursor
    printf "%s\n" "$word"
    sleep 1
done

Save it as ~/bin/foo.sh, make it executable (chmod a+x ~/bin/foo.sh) and give it your input file as its first argument:

foo.sh file


Multiple Python Versions on Ubuntu 15.10 Causing Problems

All self compiled packages almost always goes in /usr/local/ unless you change the install PATH or if the developers have other non standard things like /opt/ as default.

I assume there's a /usr/local/bin/python3 which you can rename to e.g. /usr/local/bin/python3.6.0 and that might fix it all already.

Can you do a :

find /usr/ -iname "python3"

I suggest to try :

sudo mv /usr/local/bin/python3 /usr/local/bin/python3.6.0

It is possible that "bash" still "thinks" that python3 is in /usr/local/bin/ while you have it in /usr/bin/python3
You can log out and log in again, and try again.


Can I found out that somebody killed my process?

Anyone who wants to kill another users process would have to do this as superuser and you could observe the superuser switch in /var/log/auth.log. Finding a sudo kill ... there would be kind of the smoking gun. Other than that ... nope.

But you could run your script in the foreground maybe inside screen, and set traps for the kill signal and similar stuff. This would still not show you a kill -9, but make things more observable in general.


try entering ubuntu, open the terminal and type "sudo update-grub", maybe after this you can see windows on your boot menu.


It looks like grub-mount is trying to edit a read only file system and has hung.

It should be safe to send a signal with kill to ask it to give up (send 15, and if needed after a few seconds 2, and if needed after a few seconds 1, if it's still running use -9 and report it to the maintainer) (if the pid number changes start with 15 again )

It's likely to exit non-zero which may effect scripts waiting on it, but the only thing you can do about that is file a bug report and ask the maintainer to have it skip read only file systems.

Note that there are some related bugs they are working on.


Weka windows always open in a different workspaces

This seems to be a bug in compiz related to either

multi-monitor setups (Bug #874146 “New windows open on the wrong monitor” : Bugs : Compiz Core),

or

the use of modal windows (Bug #754508 “Modal dialogs don't appear on the workspace of their parent window : Bugs : Compiz”).

So this question should probably be closed as "off topic" here in askubuntu since it is a bug and thus out-of-scope according to the FAQ.


How to use text editors in /var/www without being asked for a password

That directory and it's files are probably not owned by your user, or it's group.

Adding your user to the group that owns the directory and/or the files will likely allow you to do that. However that's a bad solution. A good solution would be do your work on a directory within your home directory and then deploy  the work to /var/www if needed.

Most modern web frameworks allow to run a development server on an unprivileged port and serving specifically only the project were you're working on. Alternatively configure your web server to serve a vhost for a directory that contains your project within your home directory.


why my external harddrive fails after connecting it to windows

Before you do anything else, please clarify and investigate this comment:

  The harddrive is 8TB but it only shows 2TB of usage

In many cases, disks over 2 TiB are problematic because of 32-bit pointer limits in MBR partition tables and in some disk drivers and even hardware (especially USB-to-disk interface hardware). Traditionally, disk sectors are 512 bytes in size, and 2^32 x 512 bytes works out to precisely 2 TiB. (Note: 1 TiB = 1024^4 bytes; 1 TB = 1000^4 bytes.) Thus, if a driver or hardware component has a 32-bit limit and if the disk is larger than 2 TiB, you can see some odd effects -- typically, the disk's size will appear to be some value under 2 TiB, because the size will "wrap around," much like an old car's odometer with too few digits to register a high-mileage value. Occasionally these limits appear in one OS (typically Windows) but not another, which can create real problems for inter-OS usage. Something similar can happen if you use a disk inside a computer (where the problem is less likely to manifest) and then try to access it using a USB adapter or external USB enclosure (many such devices impose a 32-bit limit).

Some external USB enclosures try to work around this limit by "translating" sector sizes -- they take groups of eight 512-byte sectors and convert them into individual 4096-byte sectors. This raises the 2 TiB limit to 16 TiB, but it means that moving the disk between the external enclosure and internal use (where no such translation occurs) is even more problematic, since most disk accesses and references are done by sector value, and those sector values are not consistent between the two interface types.

A less problematic explanation for the discrepancy you report is that the disk might use MBR, which has its own 32-bit limit. The newer GPT partitioning system raises that limit well beyond current needs by using 64-bit pointers. If the disk is partitioned with MBR and uses 512-byte sectors, it will top out at 2 TiB, even if it's an 8 TB model. This in and of itself should not cause data corruption, but of course you'll be able to use barely over 1/4 of its capacity. Switching from MBR to GPT is an easy solution in this case. My gdisk program (included standard in Ubuntu) can do this, but you'll need to either resize the partition or create a new one to use the additional capacity after the conversion. See this page of the gdisk documentation for information on how to do the conversion.

In any event, some additional information will help clarify this question:

The output of sudo parted /dev/sdb print (changing /dev/sdb to the disk identifier) in Linux
Clarification on the disk's claimed size
Whether you bought the disk as an external disk or created an external disk yourself by placing an internal disk in an enclosure you bought separately
Clarification on whether you've always used the disk as an external model or if you've used it both internally and via your enclosure
Information on the type of interface the external enclosure uses (USB, FireWire, eSATA, etc.)


Is there a filesystem that writes everything to nothing?

Yes, you can write to /dev/null, but you might need root permissions (not sure about that, just try). You can also delete files by moving them there, e.g. mv justanytrash.txt /dev/null


It's strange but it seems 18.04 has no calligraplan package:

https://packages.ubuntu.com/search?keywords=calligraplan&searchon=names

This package is however included in earlier and newer ubuntu releases.

I found some service with kplato package, it should be the same application probably:

https://ubuntu.pkgs.org/18.04/trinity-r14-amd64/kplato-trinity_14.0.5-0ubuntu18.04.0+0_amd64.deb.html


Where can I find a Netbeans nightly build?

Check the following link, i hope it helps a bit:

https://launchpad.net/ubuntu/+ppas?name_filter=netbeans


13.04 desktop is incomplete - top bar disappears and no side bar

Try resetting unity to fix any errors. Unfortunately the old way to reset unity was disabled in 13.04, so you'll need to install a package.

If you can make it to your desktop, press Ctrl-Alt-t to open a terminal window. Then install the unity-reset package by typing the following

wget "https://launchpad.net/~amith/+archive/ubuntutools/+build/3910667/+files/unity-reset_0.1-8_all.deb"
sudo dpkg -i unity-reset_0.1-8_all.deb

Then type:

unity-reset

After a moment your panel and launcher should appear.


It does appear the volume group is active. But not showing any signature of a file system as though the logical volumes are not formatted.
Perhaps the metadata for the logical volumes has been lost
 You can gather more data about the volumes with the commands : pvdisplay,pvscan,vgscan,lvs,lvscan.

Try checking the file systems (if ext) with e2fsck.

e2fsck /dev/mapper/{volumegroupname-logicalvolumename}

Maybe an xfs file system, however that should be listed with lsblk -f as you have already done.
The volume group has a UUID but there is no UUID or filesystem type listed for the lv's(logical volumes).

If none of that helps and you are absolutely sure there is data there then I would suggest reading up on the testdisk command and see if that will lead you to a solution.


How to setup Ubuntu as a backup server for my Windows computer?

You want to install and configure Samba. I will assume you are using Ubuntu Server 12.04. If you have a desktop installed there may be all kinds of GUI configuration tools you can use but let's keep this simple.

This should install Samba if you don't already have it:

sudo apt-get install samba

Now you should have the file /etc/samba/smb.conf so edit this and add these lines to the end:

[backup]
path = /home/username/backup
browsable =yes
writable = yes
guest ok = yes
read only = no

Now read the new configuration by running this command:

sudo service smbd reload

Finally, make sure /home/username/backup exists and is readable and writeable by everyone:

mkdir /home/username/backup
chmod a+rwx /home/username/backup

You should now have a working share. If the IP address of your server is 192.168.0.2 you could visit \\192.168.0.2\backup from Explorer and see the directory and read and write files.

Note that there is no security here. Anyone on your LAN can access your files. But this should get you started.


Apologies for submitting an answer without knowing for sure if this is the solution. I odn't have enough rep to comment yet.

Try adding this to your GRUB: nvidia-drm.modeset=1 alongside nouveau.modeset=0. Make sure your BIOs settings are correct, too. If you installed in legacy or UEFI, boot in to the correct mode, turn off that strange setting, I believe it is called Secure Boot in BIOs if you have it.

Did you follow proper procedure preceding a distribution upgrade? Prior to upgrade, safe procedure dictates the removal of graphics drivers and their repositories, then adding them again after the system upgrade reboot. If you didn't, what you might be able to do is enter terminal via recovery mode and try sudo apt remove nvidia* --purge. Ubuntu should run fine with built in drivers. I would also definitely remove one card and boot up, then install drivers for both (if that's how it works, I'm not well-versed). As I understand dual card setups have a slew of issues, and running a unix based system instead of Windows sounds like a tough situation.


What is the proper way to convert .flac files to 320 kBit/sec .mp3?

First of all you must make sure that it's installed.

sudo apt-get install libav-tools

It should have lame and flac codecs, now is just create a bash script to finish the job:

$ cat > flac2mp3

Here the shell will wait for your commands, copy and paste this:

#!/bin/bash
[[ $# == 0 ]] && set -- *.flac
for f; do
  avconv -i "$f" -qscale:a 0 "${f[@]/%flac/mp3}"
done

Now press Ctrl + D. Make your script executable chmod +x flac2mp3. Now go you can use it like this:

./flac2mp3 /path/with/all/my/flacs/*.flac

You can also copy the script to somewhere in your PATH and then cd to the directory with the flacs and execute it.

With regards to the following parameter used above:

-qscale:a 0

will not actually give you a exact 320k file, although it is probably the best setting to use anyway. The suggested settings actually give a target bitrate of 245 kbits/s with a range of 220-260. If you really wanted 320k mp3s you would have to go to CBR and use:

-c:a libmp3lame -b:a 320k

but you would need great ears to notice the difference...

Reference:

https://wiki.archlinux.org/index.php/Convert_Flac_to_Mp3#With_FFmpeg


What tools can I use to a text overlay to a video?

You can use Openshot or Kdenlive to achieve this effect.

Click here to install Openshot:

  Openshot

To add text to your video, go to

Title→New Title

or

Title→New Animated Title

in the menu. You can add effects and transitions to Titles as you would to any other component of the video.

Click here to install Kdenlive:*

  Kdenlive

You can add a title clip (text) to your video by going to:

Project→Add Title Clip

Or you can do it by right clicking on the project tree and clicking "Add Title Clip".

As with Openshot, you can add effects and transitions to Title Clips.

**Kdenlive will pull in some KDE dependencies.*


Startech docking station: Video ports not working

You need to install the Displaylink driver which you can get here:

https://support.displaylink.com/forums/287786-displaylink-feature-suggestions/suggestions/35648710-support-ubuntu-18-04


Based on my own Q&A on Unix&Linux on a similar question.

As Stuart pointed out very well in his answer, valid values are integers in the range of -1000 to 1000 for oom_score_adj. The lower the value, the lower the chance that it's going to be killed.

It's very inconvenient to have to change this value over and over again once you restart the application. The information is simply lost after the process has terminated. Upstart (the init daemon in Ubuntu), has a nice option for this to configure for daemons to make sure it's set whenever it has (re)started:

  oom score

  [...] snip [...]

  Example:

# this application is a "resource hog"
oom score 1000

expect daemon
respawn
exec /usr/bin/leaky-app

So, basically, you can edit the /etc/init/myservice.conf configuration file for the services you like to change, to include a line oom score -1000. I do assume that the services 'pbs' or 'gridengine' you're talking about in your question is Upstart-enabled, otherwise you'll need another way to change this permanently.


Update-rc.d will try to modify the existing runlevel links. If they don't exist, it throws an error.

Try the default option to create the links.

update-rc.d -f script defaults


How do I cache packages for a snapcraft cleanbuild?

The basic principles as outlined in popey's suggestion work:

Set up a caching proxy on the host (or elsewhere, depending on your preferences, I'll assume host): apt-cacher-ng, squid-deb-proxy or squid itself.
Get the host IP address (as seen by the container):

export LXD_ADDRESS=$(ip -4 -o address show dev lxdbr0 | awk -F'[ /]*' '{print $4}')

Use it to set the default profile proxy settings:

printf '%s\n' '#cloud-config' 'apt:' " proxy: http://$LXD_ADDRESS:8000" |
  lxc profile set default user.user-data -

Success!

However, there are a couple of caveats.

snapcraft cleanbuild downloads a lot of packages by some other mechanism than the usual apt-get, which isn't affected by this configuration. This insanity is seen in this part of the output:

Preparing to pull glue
Pulling glue
Preparing to pull cassandra
Get:1 http://archive.ubuntu.com/ubuntu xenial InRelease [247 kB]
Get:2 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB]
...
Get:46 http://archive.ubuntu.com/ubuntu xenial-backports/universe Translation-en [3004 B]
Fetched 26.0 MB in 6s (4237 kB/s)
Get:1 ca-certificates-java_20160321_all.deb [12.9 kB]
Fetched 12.9 kB in 0s (0 B/s)
Get:1 libxdmcp6_1.1.2-1.1_amd64.deb [11.0 kB]
Fetched 11.0 kB in 0s (0 B/s)
Get:1 init-system-helpers_1.29ubuntu4_all.deb [32.3 kB]
Fetched 32.3 kB in 0s (0 B/s)
Get:1 default-jre-headless_1.8-56ubuntu2_amd64.deb [4380 B]
Fetched 4380 B in 0s (0 B/s)
Get:1 default-jdk_1.8-56ubuntu2_amd64.deb [968 B]
Fetched 968 B in 0s (0 B/s)
Get:1 libkrb5-3_1.13.2+dfsg-5ubuntu2_amd64.deb [273 kB]

There are quite a few of these, and the individual requests make them slow as hell anyway, and that's not counting that that the apt proxy settings set earlier don't affect them.

So, I set the http_proxy environment variable instead:

lxc profile set default environment.http_proxy "http://$LXD_ADDRESS:3128"

And similarly for HTTPS, since some other downloads in the container used HTTPS. I usually prefer apt-cacher-ng, but it doesn't support HTTPS CONNECT, so I switched to squid.


I am a maintainer of keepalived, and it is I who has implemented vrrp_strict.
First of all I am sorry you have had trouble when upgrading the version of keepalived you are using, and the time you have consequently lost.
We do try to maintain backward compatibility with old configuration supported by older versions of keepalived, but sometimes that is not always possible, especially if the code is not working in accordance with the documentation, or if a bug fix requires a slight change in functionality.
As the keepalived.conf(5) man page says, vrrp_strict is intended to enforce strict VRRP protocol compliance. When it was initially implemented it did not check every aspect of configuration options which did not comply with the RFCs, but as versions have moved on that enforcement has improved. This is to help configure keepalived when interworking with a strictly conforming VRRP implementation.
In this case, vrrp_strict was specified, but keepalived v1.3.5 did not apply a check for accept mode. That check was subsequently added, since VRRPv2 does not support accept_mode.
The reason there was no error logged was that as far as keepalived was concerned there was no error; it was simply applying the default for a parameter (accept/no_accept) that was not specified. Had accept been configured, keepalived would have logged: "(VI_1) warning - accept mode for VRRP version 2 does not comply with RFC3768 - resetting".
The RFCs envisage VRRP being used on IP routers, with additional routers being able to backup the main router, and that the VIPs are addresses that naturally belong to the main router, but that backup routers will support for routeing purposes in the event that the main router is not available. It therefore has the concept that only the main router should be addressable on any of the VIPs, since they are the main router's own IP addresses, but the backup routers should not be addressable via the VIPs. The only purpose the VIPs are configured on backup routers (when they become master) is so that they can respond to ARP requests so that end stations can send packets to their IP address for onward forwarding. This is why vrrp_strict sets no_accept mode as the default if the priority of the VRRP instance is not 255.
Given the distros you have indicated you have been using, I am assuming that you have moved from v1.3.5 to v2.0.19 (or v2.2.21 if using the keepalived snap).
Unfortunately I cannot see how we could have done this better. vrrp_strict had been configured, and keepalived v1.3.5 had not fully implemented that; over time the implementation of vrrp_strict has improved to better meet what the man page states it does.
If there are any suggestions regarding how this sort of thing can be done better, we would be very happen to consider them.
I will update the keepalived.conf(5) man page to better document the checks that are made when vrrp_strict, and it will now say the following:
    # Enforce strict VRRP protocol compliance. This currently includes
    #  enforcing the following. Please note that other checks may be
    #  added in the future if they are found to be missing:
    #   0 VIPs not allowed
    #   unicast peers not allowed
    #   IPv6 addresses not allowed in VRRP version 2
    #   First IPv6 VIP is not link local
    #   State MASTER can be configured if and only if priority is 255
    #   Authentication is not supported
    #   Preempt delay is not supported
    #   Accept mode cannot be set for VRRPv2
    #   If accept/no accept is not specified, accept is set if priority
    #    is 255 aand cleared otherwise
    #   Gratuitous ARP repeats cannot be enabled
    #   Cannot clear lower_prio_no_advert
    #   Cannot set higher_prio_send_advert
    #   Cannot use vmac_xmit_base


What are the advantages/disadvantages of different SSD to HDD cacheing options (dm-cache, flashcashe...)?

I really don’t know where to start, since all this is excellent information.  I will start with some info about SSD’s, then a description of all the different caching methods, and just go from there.  I hope that you

Advantages/Disadvantages

Price: SSDs are somehow expensive
Maximum and Common Capacity: High capacity SSD’s are very rare and
expensive
Speed: This is where SSDs gets the edge
Durability: An SSD has no moving parts

Best to have a hybrid system, to have the best of both worlds (capacity, reliability, speed, etc.)

  The Linux 3.9 kernel (made available on April 28, 2013) introduces SSD
  caching. The kernel's Device mapper now includes a cache target called
  dm-cache that enables SSDs or other storage device to be used as a
  cache for a hard drive. It essentially speeds up data writes and reads
  as it allows the faster SSD to first cache data and then transfer it
  to the slower hard drive.

Source:Iwn

  Flashcache is a module originally written and released by
  Facebook(Mohan Srinivasan, Paul Saab and Vadim Tkachenko) in April of
  2010. It is a kernel module that allows Writethrough caching of a drive on another drive. This is most often used for caching a
  rotational drive on a smaller solid-state drive for performance
  reasons. This gives you the speed of an SSD and the size of a standard
  rotational drive for recently cached files.  FlashCache is a general
  purpose writeback block cache for Linux.

Source:ArchLinux

  Bcache is a Linux kernel block layer cache. It allows one or more fast
  disk drives such as flash-based solid state drives (SSDs) to act as a
  cache for one or more slower hard disk drives.

  Hard drives are cheap and big, SSDs are fast but small and expensive.
  Wouldn't it be nice if you could transparently get the advantages of
  both? With Bcache, you can have your cake and eat it too.

  Bcache patches for the Linux kernel allow one to use SSDs to cache
  other block devices. It's analogous to L2Arc for ZFS, but Bcache also
  does writeback caching (besides just write through caching), and it's
  filesystem agnostic. It's designed to be switched on with a minimum of
  effort, and to work well without configuration on any setup. By
  default it won't cache sequential IO, just the random reads and writes
  that SSDs excel at. It's meant to be suitable for desktops, servers,
  high end storage arrays, and perhaps even embedded.

  The design goal is to be just as fast as the SSD and cached device
  (depending on cache hit vs. miss, and writethrough vs. writeback
  writes) to within the margin of error. It's not quite there yet,
  mostly for sequential reads. But testing has shown that it is
  emphatically possible, and even in some cases to do better - primarily
  random writes.

 Source:Bcache

Bcache  has a big disadvantage, and that it takes away memory from the system to implement the cache.

  EnhanceIO is a solution that runs beneath the application layer,
  enabling applications to utilize the performance benefits of SSDs
  without major IT infrastructure changes. An SSD cache can yield most
  of the benefits of switching from HDDs to SSDs at a fraction of the
  cost of an all-SSD system. A cached system typically operates on less
  power than an HDD-based system of similar performance, and that
  creates a side benefit by reducing cooling requirements.

  An SSD cache can also extend the useful life of an existing system by
  improving performance to meet growing demands through an incremental
  investment, rather than through a wholesale upgrade/replacement of the
  existing system.

  Caching also enables faster access to the data without the extra
  storage administration overhead to acquire and install new disk
  shelves, configuring new LUNs and migrating data to the new LUNs.
  Caching is almost transparent and requires little if any downtime.
  EnhanceIO is based upon Flashcache.

Source:Stec-Inc

  bcache is the most worthless of all because it requires specially
  prepared (formatted) data partition. This makes it difficult (if
  possible) to attach cache to existing partition with data as one would
  need 200% capacity and to perform long data-moving in order to
  activate/deactivate caching.

  The brilliance of EnhanceIO is that it doesn't need intermediate
  device at all and can be attached to any block device on-the-fly even
  when device is already mounted. Another super-cool thing is that you
  can attach EnhanceIO cache not just to partition but to partitioned
  block device to cache all its partitions at once. Just like flashcache
  enchanceio modules are built with DKMS and can be used with older
  kernels.

 Source: Debian

  DM Cache Advantages

  DM caches use a simplified architecture, which makes them adaptable
  and easy to customize. Users can adjust the block size and the cache
  capacity based on the amount of data it will have to handle or on the
  value of the data. If a particular application needs to store a great
  deal of data in sequence, users can configure the cache for that
  purpose. If a user wants to record information in a database
  simultaneously with the cache, that won't interfere with the cache's
  operations.

  DM Cache Dis-Advantages

  One drawback to using a DM cache is that the Linux operating system
  has limited space for storing metadata. If the cache is large, and
  includes lots of small blocks, that adds up to a lot of metadata for
  the stored information. To solve this problem, the user must increase
  the block size. Another possible problem is that, after a server
  crash, the cache metadata may no longer match the cache contents,
  though it is possible to restore the correct configuration eventually.

Source: Complements of Fraser Sherman

So from the above information it’s clear that EnhanceIO is the way to go, but in my opinion since it’s based on Flashcache, I would go with flash cache.  But I will definitely try both of them before making a final decision.


You can just add it yourself.

sudo apt-get update; sudo apt-get install font-manager


When GRUB is loading, shortly after the BIOS finishes loading, quickly press shift or esc. This should allow you to boot the recovery mode.


Use of an external Hard Drive for backups

Yes, you can not use an unformated disc. Plus if it is second hand it might have a Windows filesystem.
ext3 or ext4. I would go for ext4 myself.
No, if you solely use it for backups do not split it up.
Yes, gparted is the name of the program.


SSH refusing connection after changing default port

I wanted to share my experience for anyone else that may run into this.

After changing the port and restarting the SSH service as you also tried, I was still not able to connect on the new port I specified. When I ran sudo netstat -lntp | grep ssh it showed that my SSH service was still listening on port 22, despite supposedly successfully restarting the service.

Only after rebooting the machine and re-running netstat I saw my service was finally listening on the specified port.


Startup problem in a fresh 12.10 installation

Suggest you do the following

Put the livecd and test/see if all is working. This is to ensure everything with you system is well.
Try login with Ubuntu Classic mode.
Last possibility which i doubt is perhaps hard disk is corrupt.
If you do a single user mode and paste the output of dmesg that will be great.


You can't. While converting FAT => NTFS is possible under Windows, converting the other way around is not. As a general rule, changing the file system means formatting your drive and loosing all your data. There is no way around this. In fact, that's precisely what formatting means (edited for brevity):

  Disk formatting is the process of preparing a [...] hard disk drive for initial use. In some cases, the formatting operation may also create one or more new file systems. [...] The third part of the process, usually termed "high-level formatting" most often refers to the process of generating a new file system.

So, changing a file system is formatting and formatting deletes your data. Now, it is actually possible to restore the data lost when formatting a drive. In general, when a drive is formatted, the data is not actually overwritten. It will still be stored on the hard drive but in a way that is not accessible without the use of special tools. This is really not something you want to do unless you have formatted by mistake and need to recover your data.

If your objective is to change the filesystem of one of your drives, you should just copy all your data somewhere else, then format, and then copy the data back. You can use mkdosfs as suggested by Dhaval Simaria to create the new file system.

Finally, you should note that there is very rarely, if ever, a reason to use FAT32 today. NTFS is better in pretty much all ways.


Create bootable Windows 8.1 iso using ubuntu

Use WINUSB.
http://www.geekthis.net/blog/91/create-bootable-windows-usb-in-linux
Or for the (.deb) download use this link:
http://en.congelli.eu/prog_info_winusb.html


At the command line run:

df -h | grep boot

This will show you how much space is free on your /boot partition. In my case it looks pretty bad.

/dev/sdb1                    472M  460M     0 100% /boot

As already mentioned, you can clean up old kernels and packages to help free up some space.

sudo apt-get autoremove --purge

The operation can take quite a while as it looks for old kernels and other packages which can be removed.

Then run df -h | grep boot again to check your space on /boot

/dev/sdb1                    472M  143M  306M  32% /boot

Much better!


I had the same problem, and I solved it by formatting the partition as cleared (the last option of gparted), apply changes and then create a new partition table as msdos and apply changes again. After that you only have to create a new partition in the free space.

I hope this help you


Why is baloo such a resource hog in kde?

Updatedb only stores the filename. Baloo on the other hand indexes the filename, along with the content, mimetype and modification time of the file. Reading and indexing the content of files is what makes it consume more CPU.


How to list recursive file sizes of files and directories in a directory?

apt-get install ncdu

It is interactive too so if you want to check on a sub folder just UP, DOWN, and Enter to it.


What is this KDE cursor theme with the colorful loading circle?

The cursor I was searching for is called Breeze (obsidian). I found it thanks to @edwinksl's help.

The cursor is available for Windows here: https://az4521.deviantart.com/art/Breeze-Cursors-for-Windows-628166238

For Ubuntum it's available in the breeze-cursor-theme package:

sudo apt install breeze-cursor-theme


11.04 unable to read DVDs and CDs burned in 11.04?

This problem has been encountered by other Natty users and has been fixed with the following two commands.

Open the Accessories;Terminal and enter the following command to get greater CD support:

sudo apt-get install ubuntu-restricted-extras

Next enter this second command to enable greater DVD support:

sudo /usr/share/doc/libdvdread4/install-css.sh


What command runs when I SSH into a server?

That's generally /bin/login, but ssh is usually a special case — unless UseLogin yes is specified in the sshd_config, it does the session setup itself.  Much of the session is actually managed via PAM, though.

/etc/motd is often printed by /etc/profile or a script sourced from there; it's read by your login shell.


You can download an Ubuntu package for PeaZip from their website:

http://www.peazip.org/peazip-linux.html

You'll probably want one of the GTK2 versions unless you're using KDE.


Any known pitfalls when installing on windows 10?

If you are doing a clean installation of Ubuntu on a windows 10 pre-installed laptop, you might have some problems (listed below) which can be solved.

Secure boot : you might need to disable secure boot in your BIOS menu before installing ubuntu.
If you cant go to BIOS menu during startup, fast start up feature may be enabled. try disabling it in control panel>power options. and restart.

If you want to install Ubuntu alongside Windows, a detailed solution is given here. How can I dual-boot Windows 10 and Ubuntu on a UEFI HP notebook?
If you face any other problem, please ask specifically.


When you get the black screen, try installing the Nvidia module.  Open a console with CtrlAltF1, Log in, then type

sudo apt-get install nvidia-current
sudo reboot


You can disable the need to login with a password by editing /etc/lightdm/lightdm.conf and adding these lines:

autologin-user=Jack
autologin-user-timeout=0

See here.


Cannot find appropriate C compiler on this system

It looks like you don't have gcc installed.
In case you specifically need gcc-7, you can install it with
sudo apt install gcc-7

Otherwise you can install the package gcc or build-essential(which would provide a later version of gcc).
In case this program bootstrap wants to have gcc-7 at the specific location /usr/local/bin/ and that cannot be changed, you can symlink it.
sudo ln -s /usr/bin/gcc-7 /usr/local/bin/gcc-7


Can side-by-side installs of Ubuntu 17.10 share a common ZFS pool?

Yes that is possible, as long as you do not import the pool at the same time on two running Ubuntu instances.
But you have to force import the pool when switching the Ubuntu instance, since ZFS checks the hostid when importing the pool and normally fails if that does not match with the one stored in the pool.


What is taking up so much space on my disk, beside the filesystem?

If you use Disk Analyzer as a normal user there can be some files that you can't access or see. You can try to start it with superuser privileges. Open a terminal, or press ALT+F2 and type:

gksudo baobab

Baobab is the geeky name of the Disk Analyzer if you are wondering. Maybe it can now show you where those missing megabytes are.


"bash: ./cents: no such file exist or directory" while trying to run a program that has already been compiled

Firstly using the gcc switch -c you are telling the compiler to only compile and not link which doesn't produce an executable binary to get an executable binary you need to not use this switch. The correct command would be:

gcc cents.c

However since this command does not specify the output file name the default name a.out will be used for the binary so you probably want to use this command:

gcc cents.c -o cents

Which will produce an executable binary called cents which can then be executed with

./cents

As for your other question you don't run header files that is not their purpose, header files are source code files the same as .c except their job is to be processed by the c preprocessor. Generally they are used to contain function prototypes for libraries to ensure that the same definitions are used throughout the project even if later the function requires a change to the prototype this helps to minimise errors and resulting bugs when changes are made in the program since the risk of someone missing a source file when changing the definition is otherwise high in large projects.


rsyslog set 3 Access Points to log to same file?

Maybe if $fromhost-ip isequal '10.10.10.14' then /var/log/aps.log ?

You can also try :HOSTNAME, isequal, '10.10.10.14' /var/log/aps.log...