Tips Archives • Page 14 of 66 • Linux Tips

How To: Make A Linux Install USB

Today’s article is going to be a rather basic article, with worthwhile information, about how to make a Linux install USB. This won’t be too complicated, even if it looks complicated initially. It probably won’t even be a very long article.

If you want to install Linux, you will need some sort of install medium. That can be almost any sort of drive, including some distros that are still small enough to fit on a CD. Heck, if you can get your computer to boot to it, you could even use a MicroSD as your installation media.

We’ll be doing this in the terminal. Why? Well, because it’s not that hard and it’s a fairly universal process. You won’t even need to install anything new! But, if you don’t have any interest in doing this in the terminal (or if you’re not using Linux right now) you can always do this with a GUI. See the following article for more details:

balenaEtcher: A Tool To Turn Linux .ISO Files Into Bootable USB Drives

There’s also Rufus, should you be using a Windows computer. You have options outside of the terminal. Though, I haven’t done an article on using Rufus. I don’t have any Windows devices. (If you want to write said article, feel free to let me know. I love guest articles.)

What You Need:

These are the tools you’ll want to have available. It’s not a long list, so we won’t have too much to deal with.

A blank USB drive, large enough to hold the data.
Any distro with lsblk.
The ability to unmount a disk.
A distro with the dd command.

So, I’ll assume you have the first aspect covered. Everything else is software. They’re standard tools that are available on all but the tiniest of distros.

The first tool is lsblk, which the man page describes as:

lsblk – list block devices

Then you’ll need the obverse of mount, which is unmount. This is a part of the mount command. It doesn’t have a command of its own. That mount command is described as:

mount – mount a filesystem

And, finally, you’ll need the dd command. That’s simply described as:

dd – convert and copy a file

And that’ll be all you need. Well, you’ll need an open terminal, of course! So, let’s cover one way that you can…

Make A Linux Install USB:

Like I said, you’re going to need a USB drive. This drive must be big enough to hold the data. You’ll need to insert the drive and then open the terminal. To open the terminal, just press CTRL + ALT + T or open it from your application menu.

With your USB inserted, you need to identify where it is mounted. You can do that by running the following command:

lsblk

lsblk

You should be able to easily identify the USB drive by the size of the drive. The data you want will begin with “sd”, often something like “sdb” or “sdc” (enumerating as you increase mounted storage devices).

Take that information and run the following command:

unmount <disk_indentifier>

1	unmount <disk_indentifier>

The next command might look complicated, but just follow the directions and you shouldn’t have any trouble as you make a Linux install USB. The command looks like this:

sudo dd if=/path/to/distro.iso of=/dev/<disk_identifier> bs=4M

1	sudo dd if=/path/to/distro.iso of=/dev/<disk_identifier> bs=4M

For example, if the disk identifier was “sdc” and the path to the .iso was something like “~/Downloads/Lubuntu_22.04.iso” the command would look like this:

sudo dd if=~/Downlaods/Lubuntu_22.04.is of=/dev/sdc bs=4M

1	sudo dd if=~/Downlaods/Lubuntu_22.04.is of=/dev/sdc bs=4M

Then, just wait a few minutes. Let the dd command do its thing and you’ll end up with a bootable USB drive that will let you install Linux. (This also works for other image files, of course.)

Closure:

See? It’s not that complicated to make a Linux install USB. So long as you pay attention, you won’t have much to worry about. There are a few commands that you need to worry about, but those are basic commands in this instance.

I will warn you to be absolutely certain of the path for the dd command because it has the potential to make you have a really bad day. But, if you don’t want to deal with installing a GUI application, or you are in a position where you can’t install a GUI application, this is a way for you to make a Linux USB installation drive to get yourself out of a sticky situation.

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Update Flatpaks From The Terminal

Today’s article is just going to be nice and quick. It is just going to be about how you can update flatpaks from the terminal. This might be something you’re interested in learning. So, if you want to know how to update flatpaks from the terminal, this is the article for you!

Trust me, this shouldn’t take too long. That’s good because I’m not sure how long I have! I’m having some desktop computer issues. I have laptops, yes plural, available, but I hate typing on them. I could just hook up an external monitor and keyboard, but that’s a lot like work. If I was interested in doing work, I’d investigate why my desktop PCs keep dying.

What Is A Flatpak:

A flatpak is an application package format. To enable flatpaks, you’ll have to install some software first. That seems like a good article that hasn’t been written yet.

Anyhow, a flatpak comes with all the dependencies it needs to run. It is also run in a sandbox, meaning it is more secure as it runs independently of the operating system and other applications. As they run independently, they’re able to be installed (in theory) on any distro. You don’t need to make a flatpak for each distro’s package manager, you can just make the one flatpak and it should work everywhere.

If you have something like the Gnome Software Manager and you’ve installed the initial flatpak software (software that enables you to use these packages in the first place) then you’ll see that it integrates flatpaks into the system. In that case, flatpaks will update with the rest of the system and you don’t need to worry about updating flatpaks in the terminal.

On the other hand, this may not be true for you and you may not realize that you can update flatpaks from the terminal. Which means this is for you…

Update Flatpaks From The Terminal:

Of course, this means you need an open terminal. Just press CTRL + ALT + T and your default terminal should open. You may need to open the terminal from your application menu, but the above key bindings are fairly universal.

The command is really simple if you want to update flatpaks from the terminal. To do so, you simply run this command:

flatpak update

1	flatpak update

Notice that you do not need sudo or any elevated permissions. Many folks list this command as a sudo prefaced command and that’s not necessary. The flatpaks installed are installed in a way that the files belong to the user. As such, there’s no need to use elevated permissions.

While you’re there, there’s a lot that one might not know about the flatpak application. I highly suggest you check out the man page to learn more – as there’s quite a bit that you can do with the application.

man flatpak

1	man flatpak

Yeah, that should show you all the options you have. There are far too many options to cover in this short article about updating flatpaks from the terminal.

Closure:

So, yeah… I told you that this would be a nice and short article. There’s a way to update flatpaks from the terminal and this is how you do it. You might as well know how to do so. It’s not complicated and might come in handy someday, especially if you’re expected to update them manually.

Let’s Mount An .iso In Lubuntu

Today we’re going to discuss something you won’t need to do often, as we learn about how to mount an .iso in Lubuntu. That seems like a fun article to write and it’s something I just had to do. So, that seemed like a good idea to me.

This shouldn’t be a very long article. I’ll try to keep it simple and straight forward. I figure if you can follow simple directions, you’ve got this licked. It’s not exactly a challenging task. Anyone willing to try hard enough can manage to follow along with this article.

I suppose we should start at the beginning…

What Is An .iso file?

An .iso file is a standard that’s used for images of optical disks. If you’ve used CD/DVD burning applications, it’s what you’re doing when you ‘burn an image’, for example. It’s a single file, meant to be written as an image, and is a file that’s meant to be an optical disk.

You’ll run into .iso files in Linux often. Pretty much every single distro out there is released in .iso format. We don’t always use them for optical disks. You’ll find that a lot of hardware doesn’t even have an optical disk drive. As such, we use the image formats for other things – like USB drives.

We burn these .iso files to a USB so that we can install Linux in the first place. When you’re faced with installing Linux and want (or need) to do it with a USB thumb drive, you’ll want to use tools like balenaEtcher.

So, with Linux at least, you’re likely to run into .iso files. They’re a useful way of sharing a disk image. You’d originally write that disk image to a disk (like optical media) as a single file and then that disk would work. If you try to write an .iso to media as just a file, it’s not going to work as something you can boot from.

You can learn more about the .iso format at Wikipedia. There are other formats for disk images, just so you’re aware. Read the Wikipedia article for more information.

The Mount Command:

We’ll be using the terminal for this command and we’ll be using the mount command for this exercise. As we’re only addressing Lubuntu (though this will certainly work in other distros) we know that the command is already installed and there’s no work for you to do there.

If you check the man page, you’ll see that the mount command is exactly what we need. The man page describes it like this:

mount – mount a filesystem

See? Exactly what we need to mount an .iso in Lubuntu! It’s perfect for the purpose.

You probably mount things all the time. If a disk is usable in Linux, it has been mounted. (You may run checks against an unmounted disk, of course.) If you plug in a USB drive, Lubuntu will happily (assuming your settings are the default settings) mount the drive for you. It’s a handy thing, to have the system smart enough to mount devices when plugged in. It beats the old way of having to mount them yourself manually.

So, the mount application is already installed and you needn’t install anything, but we will be doing this in the terminal. Yes, you can probably manage to do this with some GUI trickery, but you might as well learn how to mount that .iso file in the terminal. It’ll be good for you!

Mount An .iso In Lubuntu:

As mentioned above, we’ll be doing this in the terminal, the way it has historically been done. This isn’t going to be all that challenging, but you first need to open the terminal. To open your terminal, just press CTRL + ALT + T. That should open your terminal.

With your terminal now open, you need a .iso file for this so feel free to download a distro (such as Lubuntu) to your Downloads directory – or wherever you want it to be. You start the mounting procedure by first setting a location for the file to be mounted. Like so:

sudo mkdir /media/<name>

1	sudo mkdir /media/<name>

In theory, you can probably make the directory anywhere, but we will be dealing with convention. If you’re using Lubuntu, things should be mounted as media, and so they go in that directory.

The next step is the actual mounting of the file. This isn’t difficult, you just need to know the path of the .iso and where you just made the directory. That command would look similar to this:

sudo mount /path/to/<iso_file>.iso /media/<name> -o loop

1	sudo mount /path/to/<iso_file>.iso /media/<name> -o loop

At this point, your .iso file is mounted. You can use the file manager (PCManFM-Qt) to navigate to the files included in the .iso file. You can also list the contents of that file with this command:

ls -l /media/<name>

1	ls -l /media/<name>

With the .iso mounted, you can browse, copy, and extract files from the .iso file. You could theoretically add files to the image, but that’s not always a wise decision.

When you’re done with the mounted .iso, you can just unmount it with the following terminal command:

sudo umount /media/<name>

1	sudo umount /media/<name>

This is all you really need to know to mount an .iso in Lubuntu. Try it for yourself, you can’t really break anything.

Closure:

Well, if you ever need to mount an .iso in Lubuntu, you now know how to do so. As I told you near the start, it’s not that complicated. If you just think it through and follow directions, you’ll be all set. It’s not all that often that you need to mount an .iso, but the situation does happen. This is especially true if you’ve done a backup that was a disk image and you need to recover files from it because you’ve had something break.

A Bit About The Finger Command:

Today’s article is not going to be all that difficult to follow as the subject is just helping us learn a bit about the finger command. This probably isn’t useful for many of my readers, but it may be useful for those running full multi-user systems. So, let’s talk about the finger command.

The finger command is a bit weird. It’s an application you can call from the terminal and a protocol. It’s a tool used to get user information. It was more widely used back when things like a user’s real name and email address weren’t considered private information. In fact, finger has been used to compromise systems in the past.

Now, for the average reader, this isn’t a major concern. The average reader probably doesn’t need to know anything about finger.

See, the finger application gives you information about a user.

That doesn’t seem like much for my average reader but it’s possible to store a lot more information than just a username. On a multi-user system, you can store more than just a username. You can store fields like their email address, their workstation, their office address, their phone number, and many other fields.

As you can guess, that’s now considered sensitive information. A lot has changed since the early 70s, which is when the finger program was written, and then in the mid-70s when name/finger was proposed as a useful way to see if a person is online (logged into the system) and may be available for a meeting.

But, finger is still useful today. You’re not storing all that information anyhow. There are far better tools in an office environment these days.

Install finger:

If you install the finger application, you can check the man page to learn that finger identifies itself as this:

finger — user information lookup program

Which is what you can use it for today, especially for those of you who have more than one user on your system. You’re not storing things like email addresses in any of these fields, not as a regular desktop user. So, you can certainly install this (though there are other ways to see who is logged in or whatnot).

So, if you want to install finger, you’ll need an open terminal. To do that, you can usually just press CTRL + ALT + T. That should do the trick, otherwise, you’ll have to open the terminal manually.

With the terminal open, you’ll find finger is easily installed from your default repositories. Some examples follow:

Debian/Ubuntu/etc:

sudo apt install finger

1	sudo apt install finger

Fedora/derivatives:

sudo dnf install finger

1	sudo dnf install finger

RHEL/CentOS/derivatives:

sudo yum install finger

1	sudo yum install finger

See? It’s nice and easy to install finger. It’s likely in your default repos on other systems, so try that first before hunting it down to compile it on your own.

The Finger Command:

If you followed the above directions, you installed finger with the terminal. That’s good because you need an open terminal for this. So, you should still have an open terminal. If not, you’ll need to open one, of course…

Now, the syntax is simple:

finger <user_name>

1	finger <user_name>

The output from this command would look similar to this:

output from the finger command — See? Some useful information about the user from the finger command.

There are many options, but that’s the most useful and the one with the information you’re likely after. However, you should read the man page for this one. It’s a beauty.

For example, you can tell finger to not show anything by having a ~/.nofinger file in your home directory. You can even include your PGP key by adding a ~/.pgpkey (containing said key) if you want. As you can see, this is very much aimed at a multi-user system.

Probably the most useful of the flags is the -m flag. If used properly, it will avoid finding real names. This is useful when you want to find just the username and not match it with any real names. Usernames are unique, while real names might not be. The syntax would be:

finger -m <user_name>

1	finger -m <user_name>

Other than that, it’s a fun command to play around with. It does output some useful user information, so it’s not useless on your regular desktop system – especially if you have multiple users (and you do, technically).

Closure:

So, there’s another one for the books. Another article is done and published. This time around, we discussed the finger command. I’m not sure how many folks will find it useful, but it’s worth sharing the information. Eventually, someone will find it useful.

Remove Unused Kernels From RHEL

Today’s article is only going to apply to some of you, specifically those who use RHEL and want to remove unused kernels from RHEL. That’s a pretty narrow subset of people, but it’s worth knowing this information if you’re a RHEL user.

Red Hat is one of the oldest Linux distributions out there. Along the way, they’ve turned into an ‘enterprise’ (business class) distro. They’ve made some strange strategic decisions lately, but I’m not going to get into that in this article.

As an enterprise distro, it is not entirely free (as in cost in dollars). They are a distro that has a great deal of support for long periods. They’re meant to be stable and ideal for business use. You’re expected to pay for RHEL – sort of.

RHEL has a free version if you sign up as a developer. You can learn about the RHEL developer program at this link. I thought it was free for a few devices, but it looks like I might be wrong and that it may be more than that. From the linked page:

An entitlement to register 16 physical or virtual nodes running Red Hat Enterprise Linux.

So, that’s more than three – but you’re not going to get support. If you want to go this route, you’re expected to support yourself. Fortunately, RHEL has extensive documentation and your dev subscription will get you access to any of that documentation that’s behind a paywall. Or, at least that’s my experience.

I don’t do enough with RHEL!

Linux Kernels:

I’ve explained what the kernel is before. Linux is just the kernel. We add stuff to the kernel to make an operating system. We then add more stuff to make it a specialized operating system – such as a desktop operating system, like the readers of this site use.

Along the way, as you update and upgrade, you’ll add new kernels. These are not necessarily removed by default. They can take up quite a bit of space and you might be paying for that space (especially if you’re using RHEL as a server somewhere). So, removing the oldest kernels is just good housekeeping.

That’s all we’re doing in this article. I suppose it’d probably also work for CentOS but I don’t pay any attention to that distro these days. It’s not that I’m angry or annoyed with RHEL’s decisions, it’s that I only care for things with long-term support. I’m old and changes scare me!

We’re just going to clean up any old kernels, probably while keeping the 2 most recent kernels, to keep things nice and orderly. This isn’t something you technically have to do. You can keep all the kernels you want. But, if you want to remove unused kernels from RHEL this might be the article for you!

Remove Unused Kernels From RHEL:

Now, if you’re using RHEL as a server then you’re already connected via SSH (probably) and already have a terminal open. If you’re using RHEL as a desktop OS, you will need to open a terminal. You can just press CTRL + ALT + T and your terminal will pop open.

With your terminal open, you first need to install yum-utils. That’s nice and easy, just use this command:

yum install yum-utils

1	yum install yum-utils

(You’ll need elevated permissions unless you’re logged in as root.)

Next, run the following command to see how many kernels you have installed:

rpm -q kernel

1	rpm -q kernel

If you have more than two kernels installed, you can run this command:

package-cleanup --oldkernels --count=2

1	package-cleanup --oldkernels --count=2

You can adjust that command if you’d like. That particular command will keep the kernel you are currently using and the previous kernel. (You can boot to older kernels via GRUB if you want. That article is actually about recovery mode on Ubuntu, but the pictures should clue you in until I write an article just for this purpose.)

If you use a --count= of 1 or 0, it will remove every kernel except the one in use, it will not remove the kernel that’s in use.

That’s all you have to do. There’s nothing more to it. The command will automatically remove older kernels at the level you decided. You can keep the most recent three kernels, four kernels, or however many kernels you want. It’s not terribly complex.

Closure:

I don’t do a whole lot of RHEL articles, but it’s nice to at least write one here and there. If you’ve got extra kernels, you now know how to remove unused kernels from RHEL. It’s a pretty easy task and something even a new user can handle. If you’re a new user, go for it! It won’t break anything – in and of itself. (I’d highly recommend keeping the current kernel and the most recent kernel, just in case.)