45 Frequently Asked Questions about Linux Mint: PART 1

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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 and Part three is here.

Contents of this page:

My web browser warns me about insecure content on this website. Why is that?

1. When you visit this website, 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, most web browsers issue 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 Adsense started to deliver all of its ads by httpS. But apparently it doesn't always do that (sigh...).

How can I install applications in Linux Mint?

2. Linux Mint has tens of thousands of applications in its 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 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 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.

On an old-fashioned rotating hard disk, Linux positions the read/write head of the hard disk, above the middle of the partition and then writes files with spacing over the entire partition. On a modern SSD, the process is different, but also on an SSD it's important to prevent file fragmentation, even though its mechanical seek time is 0 (item 16).

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 doesn't get polluted much. The only cleaning actions you might want to do in Linux Mint are these.

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 Linux Mint (item 1.8).

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

8. Linux Mint uses 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 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 in Ubuntu, I see nothing?

10. That's normal. Your password is registered all right, although in Ubuntu (unlike Linux Mint) you can't even see asterisks when you type. 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 Linux Mint?

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

Acceptable performance:
Graphics card: 256 MB memory
Hard drive space: 100 GB (30 GB if you don't use Timeshift and/or Flatpaks)

Smooth running:
Graphics card: 512 MB memory
Hard drive space: 100 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 extra important to run the file manager with a protective layer, in order to prevent messing up the file permissions in your system. Because the default file manager is so much ingrained in the system as a whole, that this might easily cause problems.

For managing files as root, you therefore need to launch your file manager from the terminal with the protection of pkexec.

In order to launch Cinnamon's file manager Nemo with root permissions from the terminal, you can use this terminal command:

pkexec nemo

For Caja (MATE) it's:

pkexec caja

And for Thunar (Xfce) it's:

pkexec thunar

Note: closing the terminal might also affect the root instance of your file manager: the terminal is always in charge! So don't close the terminal window until you're done.

Sidenote: for non-root use you can also 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 (use copy/paste to avoid errors):

sudo apt-get install doublecmd-gtk

Press Enter. In Ubuntu (unlike Linux Mint) your password remains invisible, not even asterisks will show, that's normal.

Tip: Did you tweak Double Commander a bit too much and 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

What are the differences between Ubuntu, Xubuntu and Kubuntu?

14. Xubuntu and Kubuntu are both official versions of Ubuntu (official flavours or 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 Gnome desktop environment. Gnome 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 Gnome 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 Gnome 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 Gnome is.

How can I make the Grub menu visible?

15. On a single-boot computer, you don't ever get to see the Grub bootloader menu. In such a case you can make the Grub menu visible when you turn on your computer, by hitting the Esc key just once, immediately after the BIOS screen disappears.

However, hitting the Esc key just once at the exact right moment can be difficult. In that case, hit the Esc key repeatedly, immediately after the BIOS screen disappears. That increases your chances of success, but it'll give you a Grub command prompt without the menu.

No worries, however: at the Grub prompt, type normal and hit Enter. Then immediately start tapping the Esc key again repeatedly, until the bootloader menu is displayed after all.

This time, don't worry about hitting Esc too many times: tapping Esc more than once at this point, won't drop you to the Grub command prompt anymore, but will (finally!) give you the bootloader menu.

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 Linux Mint and Ubuntu)?

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 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 launch a terminal and execute the setxkbmap command 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):

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

b. Now check how your username is "under the hood": it's important that you see how it's spelled before the @ sign in the terminal.

c. From the menu, launch the application Login Window. Tab Users - Automatic login: type your username in the field for Username. Type it exactly the way you've seen it spelled in the terminal!

d. Reboot. You should login automatically now.

No avail? Then do it by hand, like this:

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

f. Copy/paste the following command line into the terminal, in order to create a particular file (it's one line):

sudo touch /etc/lightdm/lightdm.conf

Press Enter.

g. Then, in order to edit that file:

xed admin:///etc/lightdm/lightdm.conf

Press Enter.

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

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


j. 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 lower-case only.

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


k. 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 Linux Mint 19):

a. From the menu, launch the application Login Window. Tab Users - Automatic login: remove your username in the field for Username.

b. Reboot. You should land in the login window now.

No avail? Then do it by hand, like this:

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

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

xed admin:///etc/lightdm/lightdm.conf

Press Enter.

e. 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:


f. Save the file and close it.

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

How can I compare my kernel version with the upstream kernel version?

19. The Canonical Kernel Team, which creates the kernels for Ubuntu and Linux Mint, uses its own minor version numbering. This doesn't correspond with upstream kernel numbering at kernel.org, where the Linux kernels are born.

Sometimes that's a nuisance, because that makes it harder to see quickly which important improvements it contains. The news media usually only mention the version number of kernel.org....

This is how to determine exactly which upstream kernel has been used to create your kernel:

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):

cat /proc/version_signature

Press Enter.

The first part of the output shows the downstream numbering of your kernel by Canonical Kernel Team, and the last part shows the upstream kernel version that Canonical Kernel Team has used to create your kernel.

For example, on my machine:

pjotr@MD99587 ~ $ cat /proc/version_signature
Ubuntu 5.4.0-39.43-generic 5.4.41

The modified upstream kernel version in the example is 5.4.41.

How can I edit system configuration files with a text editor?

20. For editing system configuration files with the necessary permissions, you need to proceed like this (item 1.2).

Want to read more FAQ? This is part one of the Frequently Asked Questions (FAQ). Part two is here and Part three is here.

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