34 frequently asked questions about Ubuntu and Linux Mint (FAQ) - PART ONE

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Many questions come up frequently. Below you'll find a selection.

This is part one of the Frequently Asked Questions (FAQ). Part two is here.

Chrome / Chromium warns me about insecure content on this website. Why is that?

1. When you visit this website with the web browsers Chrome or Chromium, you might receive a warning about insecure content on the page.

This warning is quite unfounded, and is being caused by the advertisements. Sometimes the ads are being delivered by normal unsecured http, whereas the pages of this website are always being delivered by secured httpS.

Whenever that happens, Chrome / Chromium issues the warning that there's unsecured content on a secured page. Very bad, because it scares visitors away and diminishes my earnings from advertisements. And heck, this is even costing *Google* money...

Some time ago, this problem seemed solved, because it looked like Google started to deliver all of its ads by httpS. But apparently they don't always do that (sigh).

Google Chrome, Google Sites and Google Adsense: one would expect them to cooperate well. But those business units of Google are apparently quite unconcerned with each other.

How can I install applications in Ubuntu and Linux Mint?

2. Ubuntu and Linux Mint have tens of thousands of applications in their own software repositories, which are all freely available by the Internet. Installation is a matter of a few mouse clicks: see this manual.

How about viruses and firewalls?

3. You are well protected in Ubuntu and Linux Mint. Check this out: security.

How can I defragment the hard drive in Linux?

4. A Linux partition doesn't need to be defragmented at all. Because Linux has been built to prevent fragmentation: only insignificant fragmentation can arise, as long as the partition has more than 20% of free space.

That's because Linux positions the read/write head of the hard drive, above the middle of the partition and then writes files with spacing over the entire partition. Linux does not write the files as a contiguous block (such as Windows does) but with empty space between the individual files. This way, an individual file rarely ever gets fragmented: there is room for continuous growth of the file.

As I said, there must be at least 20% of free space on the partition, otherwise fragmentation of individual files does occur. Which slows down the system. So take care not to fill a Linux partition too much!

This advantage only applies to partitions with a native Linux format, such as EXT3 or EXT4. It does not apply to FAT, FAT32 and NTFS.

Further explanation in this pdf file.

This advantage of Linux has of course its "price": the usable amount of disk space is, because of this, 20 % lower than in Windows. But as hard disks have grown increasingly bigger over the years, this'll hardly be a problem nowadays....

Note: Unfortunately, you can find some defrag tools in the "fringes" of the Linux ecosystem. Don't use them! There's a considerable risk that they either mess up your system beyond all repair, or cause massive loss of files. It's dangerous rubbish. Without any exception.

Note: strictly speaking this is an oversimplification of the way how Linux and Windows treat their files, and therefore not entirely correct: Windows also puts some files in the middle of an partition, and Linux places some files at the beginning of a partition. But although oversimplified, the big picture is correct.

How do I keep the system clean?

5. Linux Mint and Ubuntu don't get polluted much. The only cleaning actions you might want to do in Ubuntu, are these. The corresponding how-to for Linux Mint is here.

How do I launch a terminal window?

6. An important question. This is how you open a terminal.

Where can I find the Microsoft True Type fonts Arial, Times New Roman, Courier etc.?

7. The fonts Arial, Times New Roman, Courier New, Comic Sans and so forth, are protected by copyright. But they can still be installed easily in Ubuntu. They are part of the package "Ubuntu restricted extras". See Multimedia.

Why do I have to submit my password when installing applications?

8. Linux Mint and Ubuntu use the so-called Root System, in which certain rights (for example, installing applications) are reserved to the administrator of the system. Only the Root (or administrator) can install applications. This is to protect the system. It's the single most important security feature of Linux.

In Ubuntu and Mint there's no root account by default: even the administrator himself logs in with limited user rights. The administrator can perform administrative tasks with temporary root authority (in the terminal by placing sudo before the command).

Note: After entering your password, it will remain valid for 15 minutes. During that time, you can perform a variety of system management tasks, without having to re-enter your password.

For instance, you can reboot the computer by typing in the terminal:
sudo reboot

I am not being prompted for my password, when I want to perform a second administrative task shortly after the first. Why?

9. This is normal and is arranged for ease of use. The validity of the password is only 15 minutes.

When I type my password in a terminal, I see nothing?

10. That's normal. Your password is registered all right, although you can't even see asterisks. Simply press Enter.

Do I have 64 bit or 32 bit Linux?

11. You can check whether your Linux is 32 bit or 64 bit, by means of a simple terminal command. As follows:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type (use copy/paste to avoid errors:
uname -m

Press Enter.

The output will tell you what it is:

i686 is 32 bit
x86_64 is 64 bit

What are the minimum system requirements for a computer, to be able to run Ubuntu?

12. According to my own experience, the minimum system requirements for "acceptable performance" (workable) and for "running smoothly" (optimal) are as follows:

Acceptable performance:
RAM: 1.5 GB
Graphics card: 128 MB memory
Hard drive space: 10 GB

Smooth running:
RAM: 2.5 GB
Graphics card: 256 MB memory
Hard drive space: 20 GB

How can I open a file manager with root authority (omnipotence)?

13. File management with root authority is always risky, because you can break so much so easily. But sometimes it's inevitable.

In such cases it's better not to use the default file manager (explorer), like Nautilus in Ubuntu and Nemo in Mint Cinnamon. Because the default file manager is so much engrained in the system as a whole, that this might easily cause problems. In Xubuntu it's the same with Thunar and in Lubuntu with PCmanFM.

For managing files as root, it's therefore much better to use a simple stand-alone file manager like Double Commander. For that, you can do the following:

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Type the following to install Double Commander and the gksu package (use copy/paste to avoid errors):

sudo apt-get install gksu doublecmd-gtk

Press Enter. Your password remains invisible, not even asterisks will show, that's normal.

For running Double Commander with root authority, type (copy/paste):

gksudo doublecmd

Press Enter.

Note: closing the terminal could also affect file manager Double Commander: the terminal is always in charge. So don't close the terminal window until you're done.

Tip: do you want to reset Double Commander to its default settings? Then close Double Commander and execute this terminal command:
rm -r -v ~/.config/doublecmd

(continued in the column on the right)

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What are Xubuntu, Kubuntu, Lubuntu and Edubuntu?

14. Xubuntu, Kubuntu, Lubuntu and Edubuntu are all official versions of Ubuntu (official derivatives). They differ only in the desktop environment and the standard applications. They are "under the bonnet" all the same and make use of the same Ubuntu repositories.

Ubuntu in its main version makes use of the Unity desktop environment, which in its turn is build on Gnome. Unity is particularly focused on people with few computing skills, plus it has a lot of eye candy.

Xubuntu is Ubuntu with the Xfce desktop. An excellent distro! An official member of the Ubuntu family, so of assured quality.

Xubuntu is very easy to use and has a clean, professional and functional look. No frills, which is one of the reasons why Xubuntu is very stable and reliable. Windows users get used to it right away.

Xubuntu has somewhat less "eye candy" than Ubuntu. It's not very demanding on the system resources. Many people use Xubuntu on their computers, because they like it better than the Unity desktop of Ubuntu. Or because they want to reserve as much computing power as possible for the applications.

Tips and how-to's for Xubuntu can be found here.

Kubuntu uses the Ubuntu basis and the KDE desktop environment. Where Unity is mainly focused on simplicity, KDE is aimed at providing maximum tweaking possibilities through the menu. These can be overwhelming, so I think Kubuntu is less suitable for beginners with Linux.

KDE has a lot of eye candy of its own, so it's about as demanding on the system resources as Unity is.

Lubuntu is the featherweight of the lot: very light on the system resources and easy to use. It looks a bit austere though: eye candy is almost completely absent.

Very useful for old computers.

Edubuntu is a customized educational version of Ubuntu, mainly aimed at schools. Despite the use of the Unity desktop environment, by default there are applications of both Gnome and KDE installed.

Edubuntu is also often used because of the built-in LTSP server, allowing you to work with "thin clients".

Why are there so many Linux distributions and why should I choose Ubuntu or Linux Mint?

15. This question (or rather the answer to it) has been moved to this page.

How can I make my computer shut down automatically after a set period of time?

16. It can be useful to let the computer shut itself down after a given period of time. For example when you want to listen to some music before going to sleep...

You can do that as follows:

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Now you're going to give temporary root permissions to that terminal window; type (copy/paste):

sudo -i

Press Enter. Your password remains invisible, not even asterisks will show, that's normal.

c. Determine the number of seconds that the computer has to stay on. For half an hour that's for example 30 x 60 = 1800 seconds. If you want a shutdown after half an hour, you execute the following command (use copy/paste in order to avoid typing errors):

sleep 1800 && shutdown -h now

Press Enter.

d. You're done! If you want to test it a bit: set sleep to 5. Then it should shut down neatly after 5 seconds, without dialogue windows or things like that.

How can I disable Caps Lock (in all editions of Ubuntu and Linux Mint)?

17. Some people dislike the Caps Lock key, because now and then it gets pressed accidentally, creating havoc in your typing. If you wish to disable it, that's quite easy. For all editions of the Ubuntu family and of Linux Mint, proceed like this:

Make sure that Caps Lock isn't active: the hack you're about to do, makes the Caps Lock key "dead". So if it's active at the time of the hack, it'll remain active!

Launch a terminal window.
(You can launch a terminal window like this: *Click*)

Copy/paste the following command line into the terminal:

setxkbmap -option caps:none

Press Enter.

Done! Now the only way to get capital letters is by keeping the Shift key pressed first.

Note: this command is session-only, so it won't survive a reboot. If you want to make it load automatically upon login, simply add this command line to your startup applications. Then Caps Lock will be disabled automatically, when you log into your user account.

For example, in Linux Mint Cinnamon that can be done like this: Menu button - Preferences - Startup Applications - Add - Custom command.

You can enable Caps Lock again by undoing all setxkbmap options, which is very easy. Just execute setxkbmap with an "empty" option, like this:

setxkbmap -option

Press Enter. And all is, as it was before....

How can I enable automatic login in Linux Mint?

18. Haven't you enabled automatic login during the installation of Linux Mint, and do you wish to have it now? This is how to enable it in LightDM (the default display manager in a cleanly installed Linux Mint 18.2):

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Copy/paste the following command line into the terminal (it's one line):

gksudo xed /etc/lightdm/lightdm.conf

Press Enter.

c. Now a text file should be opened. Normally it should be empty; if not, delete all existing content.

d. Copy/paste the following lines into that text file:


e. Replace your_own_user_name by, well, your own user name (surprise!).
Note that capital letters aren't allowed for the user name in this settings file! So type your user name with lowercase only.

For example, for user "John" the settings should look like this:


f. Save the modified file and reboot. You should log in automatically now.

How can I disable automatic login in Linux Mint?

18.1. Did you enable automatic login (e.g. during the installation of Linux Mint), and do you wish to undo it now? This is how to disable it in LightDM (the default display manager in a cleanly installed Linux Mint 18.2):

a. Launch a terminal window.
(You can launch a terminal window like this: *Click*)

b. Copy/paste the following command line into the terminal (it's one line):

gksudo xed /etc/lightdm/lightdm.conf

Press Enter.

c. Now a text file should be opened. Put a hash tag before each line in that text file. An example of a "hash tagged" file:


d. Save the file and close it.

e. Reboot your computer. You should land in the login window now.

This is part one of the Frequently Asked Questions (FAQ). Part two is here.

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