Chapter 2
Installing an Ubuntu Server

Ubuntu Server is a popular Linux distribution, and most likely you will install it many times in your Linux career. Gaining experience with this distro's installation process will help you become a Linux expert.

The first few times you install a particular operating system, it feels like a daunting task. And rightly so! Without proper guidance, the process can often result in frustration and lost time. Our goal in this chapter is to assist you through your first installation of the Ubuntu Server distribution. We provide step‐by‐step guidance, help you avoid pitfalls, and ultimately build your sysadmin skillset.

Pre‐Installation Requirements

A graphical user interface (GUI) uses a lot of resources on a computer system, and if the server is not needed for providing a desktop to users, those applications and utilities are typically not installed. This is the case with the Ubuntu Server distribution. If you want a GUI on it, you'll have to add that software to it after the installation.

The Ubuntu Server distribution is designed for a system that not only doesn't need a GUI, but is headless. Though that sounds like something in a horror movie, you often find these types of servers in modern server rooms. A headless system is simply a computer without a directly attached monitor. A sysadmin connects to the computer through the network to reach its text‐based command‐line interface.

Before jumping into a Linux installation, it's wise to review what is needed to make the project successful. We're assuming that you already have your customer's requirements in hand and now need to determine what is required for an Ubuntu installation on a physical or virtualized server.

In the next few sections, we'll look at the hardware requirements needed for installing the Ubuntu server distribution directly on a physical server and for installing it within a virtualized environment.

Hardware Requirements

If you plan on installing the Ubuntu Server 20.04LTS distribution directly on a headless server, your computer must support a 64‐bit processor architecture. Any of the following will work fine:

AMD amd64
ARM arm64
IBM Z s390x
Intel amd64
LinuxONE s390x
POWER8 or 9 ppc64el

Besides having the proper processor on your system, you need to have enough resources available to avoid a sluggish system. Table 2.1 shows the recommended resources to support a well‐running Ubuntu Server distro.

TABLE 2.1: Recommended Server Resources for Ubuntu Server Distribution

RESOURCE	MINIMUM	RECOMMENDED
CPU	1 GHz	1 or more GHz
Memory	1 GB	2 or more GB
Disk space	2.5 GB	10 or more GB

Keep in mind that these recommendations are only for the operating system. Increase these resources to meet the needs of the application(s) you will run on the server.

Not everyone has access to a physical server. But you can set up a virtual environment on a laptop or some old desktop you have stuffed away in your closet. Using a virtualized system on your daily laptop provides a great deal of flexibility. You can learn about Linux while sitting in the park!

Virtual Server Requirements

If you plan on running the Ubuntu Server distribution as a virtual machine, you need to ensure that the host machine's operating system is supported by the hypervisor.

For this book, we're focusing on the Oracle VirtualBox hypervisor software. Here are a few of the operating systems on which it can run:

Windows 8.1
Windows 10
macOS High Sierra
Ubuntu 18.04LTS

This list is always evolving. It's a good idea to visit the Oracle VirtualBox manual website, virtualbox.org/manual, and view the currently supported host operating systems.

Running a virtualized environment will increased the needed resources on your system. You need to make sure that the host machine can handle not only the hypervisor but the Ubuntu Server VM as well. Table 2.2 lists the recommended host machine resources for a virtualized Ubuntu Server system.

TABLE 2.2: Recommended Host Machine Resources for an Ubuntu Server VM

RESOURCE	MINIMUM	RECOMMENDED
CPU	2 GHz dual core	2 GHz dual core
Memory	4 GB	16 or more GB
Free disk space	25 GB	30 or more GB

These recommendations assume you are running only one VM at a time. You need more resources on your system if you plan on running multiple VMs at the same time or run a VM along with several other apps. Keep in mind that these resource recommendations are guidelines. They are not rules, so you may need a little more or a little less.

After you have your host system properly outfitted with resources, it's time to start downloading software. We'll cover those steps in the next section.

Finding the Software

After you determine that you have the appropriate resources but before you start the installation process, you need to have the proper software. You need to make sure that you get the correct version and type. For the larger software files, it's also critical to verify that no corruption has occurred when the software was downloaded. If you have a corrupt software file, you'll end up needlessly wasting your time.

Oracle VirtualBox

We recommend that you use Oracle VirtualBox as the hypervisor on your system. You can download the latest version of this software from virtualbox.org.

It is important that you get the correct platform package of VirtualBox. You'll see a list of potential host systems on the VirtualBox website, such as the following:

Windows
macOS
Linux

Make sure to select the VirtualBox package for the system on which the Ubuntu Server virtual machine will be running. Often people make an incorrect choice, because they confuse the host system with the virtual machine. Here's an example that may help: if you have a laptop running Windows where you plan on installing Ubuntu Server as a VM, then Windows is the host, and you want to download the VirtualBox package for Windows. Our examples in this chapter are based on a Windows 10 host system.

Ubuntu Server

To install Ubuntu Server as a VM, besides the hypervisor software (and the correct amount of resources on the host machine), you need an Ubuntu Server ISO image file. An ISO image file (also called an ISO image) is a specially formatted package file that contains all the files needed to boot a system. The Ubuntu Server ISO image file is used to boot and then install the distribution. In our case, we're installing it as a VM.

To get your hands on the Ubuntu Server ISO image file, go to ubuntu.com/download/server. If you are provided options for the download, choose the manual install option as shown in Figure 2.1.

You can start the process of downloading the ISO image file by clicking the Download button. Depending on the web browser you are using, you may have to deal with some pop‐up windows that want to confirm it is OK to download this file.

Since the ISO file is large, it's important to verify that no corruption has occurred while the software was downloading. If you have a corrupt ISO image file, you'll need to download the file again.

Snapshot of option to choose an Ubuntu Server ISO image file download — FIGURE 2.1 Option to choose an Ubuntu Server ISO image file download

Real World Scenario

CHECKING THE UBUNTU SERVER ISO IMAGE FILE

Once the Ubuntu Server ISO image file is completely downloaded, you need to verify it. To do this, we'll employ hashing. Hashing uses a one‐way mathematical algorithm to create a fixed‐length hash, which is basically a series of letters and numbers. A hash is also called a message digest, a hash value, a fingerprint, a signature, or cipher text. One cool thing about hash values is that hashing produces the same hash value for files that are the same. You can take a file with a picture in it and copy it to another location. If we use hashing to produce a hash value for the original picture file and for the copied picture file and those two hash values match, we know that the picture was not corrupted when it was copied to the new location.

Follow these steps to produce a hash value to check your image file:

On your Windows 10 system, open the Windows 10 PowerShell app by typing Windows PowerShell in the search bar and clicking the resulting Windows PowerShell app icon.
After the Windows PowerShell app window is open and you have a prompt, assuming you downloaded your Ubuntu Server image file to the Downloads folder, type cd Downloads and press Enter. The prompt should now show that you are in the Downloads folder.
Run the PowerShell hashing utility on the Ubuntu Server image file by typing Get‐FileHash ubuntu, and press the Tab key so that PowerShell autocompletes the Ubuntu Server's image filename for you. Go on to the next step before you press Enter.
Complete the rest of the PowerShell command by pressing the spacebar, typing ‐Algorithm SHA256, and pressing Enter. Be patient! It may take a while for the command to output the SHA256 hash value. You should see something similar to the following:

Don't exit the PowerShell window yet. You need to compare your resulting hash value with the current SHA256 hash value on the Ubuntu website.
Open your favorite web browser and go to releases.ubuntu.com/focal/SHA256SUMS. (If this web page has been moved, you may need to search the releases.ubuntu.com site to find the Ubuntu Server ISO image file's SHA256 hash value.)
Compare the hash value on the website with your hash value in PowerShell for the Ubuntu Server ISO image file. If they match, no file corruption occurred when you downloaded the file, and congratulations—you're ready to move forward in the installation process! However, if the hash values don't match, you need to download the file again and repeat this checking process.
Type exit at the PowerShell prompt to leave the app.

Verifying that the Ubuntu Server ISO image file is a good copy will save you time. If you tried to use a corrupt image file in an installation, it may work partway through the process and then quit before completion. That's frustrating. It's always best to check that your file is good before proceeding within an install.

PREPARING FOR A HARDWARE INSTALLATION

If you are planning on installing the Ubuntu Server distribution directly on a computer's hardware, instead of creating a VM, you need to do one additional step after checking the ISO image file: create a bootable media device. While bootable DVDs were popular many years ago, most hardware installations can be handled through a bootable USB drive. The process of creating this bootable USB (or DVD) is called burning an ISO file to a USB drive.

You cannot just copy the file to the USB. Instead, you need a special software app that will burn the ISO properly. To find the right software, open your web browser and go to your favorite search engine. Type burn a bootable USB and press Enter. The resulting list will have several sites with instructions that point to free software. Once you have your Ubuntu Server ISO image file properly burned to a USB (or DVD) drive, you're able to boot your system and perform the installation process similar to what is covered in the next section.

Now that you've verified your copy of the Ubuntu Server ISO image file and downloaded the Oracle VirtualBox hypervisor software, you're ready to start the installation. We'll cover that process next.

Running the Installation

To create an Ubuntu Server VM, you need to first install the hypervisor, Oracle VirtualBox. Once that software is up and running, you can set up and install Ubuntu as a VM using its ISO image file and the hypervisor.

Oracle VirtualBox

The Oracle VirtualBox hypervisor software will allow you to do much more than set up Ubuntu Server as a Linux VM. You can also install another version of Windows within a VM and use it to try out features or configurations you normally wouldn't do on your main system.

Real World Scenario

INSTALLING ORACLE VIRTUALBOX ON WINDOWS 10

If you have ever installed an app on Windows, the process of installing the Oracle VirtualBox hypervisor will feel familiar. It follows the typical Windows installation process.

Assuming you downloaded your VirtualBox software file to the Downloads folder, navigate to that folder and double‐click the software file. The file will have a name similar to the following, but with version numbers instead of # : VirtualBox‐ # . # . # ‐ ###### .exe.
Click the Next button in the VirtualBox Welcome window, which looks similar to the following:
If desired, in the Custom Setup window, make any modification you'd like. If you want to install VirtualBox using the defaults, just click the Next button.
In the second Custom Setup window, remove check marks from the boxes if you want to have fewer methods for accessing VirtualBox or no registered file associations. Click the Next button when you are done. If you want to keep the defaults, just click the Next button.
After reading the Warning window and you are ready to proceed with the installation, click the Next button.
You get one more chance to bail out of this installation. If you want to continue, click the Install button.
If you are not performing this VirtualBox software installation in an account that has administrator privileges, you will receive a pop‐up window asking for the administrator password. Enter the password and click the Yes button.
At this point, you will receive an installation status box that shows the progress of the VirtualBox software install, similar to the following:
After the software installation is completed, you'll receive a window letting you know that it is done. Click the Finish button to open the VirtualBox hypervisor app.
You should see a window showing the Oracle VirtualBox hypervisor interface, called the VirtualBox Manager, which looks similar to this:

Congratulations! You have successfully installed the hypervisor software! You are ready to start the process of creating your Ubuntu Server VM.

If you need to take a break, close out the VirtualBox interface window by clicking the X in the upper‐right corner. However, if you want to plow on ahead, keep it open. We'll launch into installing Ubuntu Server in the next section.

Ubuntu Server

Installing the Ubuntu Server as a VM may feel overwhelming the first time you do it, but as you complete the process a few more times, you'll feel more at ease. We'll help you through this initial instance to build confidence.

Real World Scenario

SETTING UP AN UBUNTU SERVER CONFIGURATION WITHIN ORACLE VirtualBox

Prior to installing Ubuntu Server as a VM within the VirtualBox hypervisors, you need to perform a few basic tasks to create and configure a place for the new VM within the VirtualBox app. After you have completed these tasks, you will have a folder on your host machine for the new VM as well as two files within the folder: one file for the VM configuration information and one file acting as a hard disk for the VM.

Follow these steps to configure the VM. Though only a few steps are needed to complete this part of the installation project, they are important! So don't skim through this exercise.

Open the Oracle VirtualBox app on your host system. How this is accomplished depends on the configuration you chose when installing the VirtualBox software. You may have to find it via the menu search feature on Windows 10, or you can simply click the VirtualBox icon on the desktop or taskbar. Once you have the app open, you should see a window showing the Oracle VirtualBox Manager that looks similar to this:
In the VirtualBox Manager window, using the top menu within the window, select Machine ➢ New. This will start the process of configuring the Ubuntu Server VM and produce the Create Virtual Machine window.
Enter the name Ubuntu Server in the Create Virtual Machine window's Name box.
Click the Next button to reach the Memory Size window, which looks similar to the following:
By either typing in the memory setting box or using the up‐arrow button, change the Ubuntu Server memory to 2048 MB.
Click the Next button in the Memory Size window to reach the Hard Disk window.
Double‐check that the Create A Virtual Hard Disk Now option is selected. (You can tell that a particular option is selected by the circle next to it being filled with a dark color as shown in the previous figure.) If you need to select the Create A Virtual Hard Disk Now option, click the empty circle next to it.
Click the Create button in the Hard Disk window, which will open another configuration window called Hard Disk File Type.
Within the Hard Disk File Type window, ensure that the VirtualBox disk image (VDI) is selected.
Click the Next button, and the Storage On Physical Hard Disk window will appear. This configuration window looks similar to the following:
Double‐check that the Dynamically Allocated setting is selected.
Click the Next button to open the File Location And Size window.
Click the Next button, and the Storage On Physical Hard Disk window will appear. In this window, you will see where the VM's virtual disk file will be created as well as its size. This configuration window looks similar to the following:
Change the file size to 16 GB by typing 16 within the size box.
You are now ready to create the basic configuration and virtual disk file of the VM. Do so by clicking the Create button.
You should now be back at the VirtualBox Manager window with the Ubuntu Server VM in the left pane, as shown here:

We have a few more configuration items to accomplish before the VM is completely configured.
Click the Settings button in the VirtualBox Manager's top‐right pane, which opens the Settings window for the Ubuntu Server VM.
In the Settings window, click Network in the left pane to open the Network settings window for the Ubuntu Server.

The next few steps help you to set up a second network interface card (NIC) on the Ubuntu Server. This allows your VM to act as an independent node on your network.
In the Network settings window's right pane, click the Adapter 2 tab.
In the Adapter 2 tab window, click the empty box next to Enable Network Adapter.
Still in the Network settings’ Adapter 2 tab window, use the arrow to open the drop‐down menu in the Attached To box, and select Bridged Adapter. Except for the Name box, your selections should look similar to the following:
Click the OK button to save the network settings.
You should now be back to the VirtualBox Manager window. Pat yourself on the back! You have successfully configured the Ubuntu Server VM.

All this hard work will soon pay off. You are now ready to install the Ubuntu Server distribution on the virtual machine you just configured within VirtualBox.

Real World Scenario

INSTALLING UBUNTU SERVER AS A VM

After configuring the Ubuntu Server VM within the VirtualBox hypervisor, you can perform the actual installation of the Linux OS. Conducting the installation process on a VM is similar to conducting it on a physical server. Just a few differences exist, such as loading the ISO image file into the virtualized DVD drive.

Follow these steps to install your Ubuntu Server from the ISO image file:

Open the Oracle VirtualBox hypervisor app on your host system if it's not already open.
If you have multiple VMs configured in your hypervisor, click one time on the Ubuntu Server VM to select it.
Click the Settings button in the VirtualBox Manager's top‐right pane, which opens the Settings window for the Ubuntu Server VM.
In the Settings window, click Storage in the left pane to open the Storage settings window for the Ubuntu Server. It will look similar to the following:
In the Storage settings window's middle pane under Controller: IDE, click the word Empty to open the Attributes pane for the IDE optical drive.
In the Storage settings window's Attributes pane, click the DVD image to produce a drop‐down menu, and select Choose/Create A Virtual Optical Disk. An Optical Disk Selector window will appear that looks similar to the following:
In the Optical Disk Selector window, click the Add icon, which will open the Windows Explorer utility, and you will see “Please choose an optical disk file” in the window's title bar.
Navigate to the location of your Ubuntu Server ISO image file, select the file by clicking it, and then click Open. The Optical Disk Selector window now looks similar to the following:
In the Optical Disk Selector window, click Choose, and you are returned to the Storage settings window's Attributes pane with the Ubuntu Server ISO image filename displayed under Controller: IDE.
Click OK to keep the virtually loaded ISO image file and return to the main VirtualBox Manager window.
Boot your Ubuntu Server VM by clicking the Start button in the VirtualBox Manager's top‐right pane.
You may see lots of messages go by on your screen. Let the process continue until you reach this window:
Using your arrow keys, select the language you prefer and press Enter.
In the Keyboard configuration window, select your desired keyboard layout (the defaults are typically OK), and press Enter.
In the Network Connections window, review the displayed information, and press Enter.
In the Configure Proxy window, review the displayed information, and if you need to enter a proxy address, do so. Otherwise, press Enter.
In the Configure Ubuntu Archive Mirror window, press Enter.
If you receive the Install Update Available window, select Update To The New Installer, and press Enter. You have to wait until the installer is updated. This may take a few minutes depending on the speed of your Internet connection. When it is complete, you should see the next installation window, which looks similar to the following:
In the Guided Storage Configuration screen, keep the defaults, tab to Done, and press Enter.
Read through the information provided in the storage configuration window, and press Enter. You'll receive a warning message similar to the following:

Don't let this warning message scare you. Remember that your virtual hard drive for this Ubuntu Server is merely a file on your host machine.
Tab to Continue, and press Enter.
Within the Profile Setup screen, type your first and last names in the Your Name field.
Tab to the Your Server's Name field, and type ubuntu‐server.
Tab to the Pick A Username field, and type sysadmin.
Now tab to the Choose A Password field, and type in a password. Be sure to choose one that you will remember!
Tab to the Confirm Your Password field, and type in the same password as you did in the previous step. Your screen should now look similar to the following:
Once all the fields in the Profile Setup window are filled, tab to Done and press Enter.
In the SSH Setup window, tab to Done and press Enter.
You'll receive a message in the next screen when the initial installation is complete that looks similar to the following:
Press Enter to select Reboot Now.
Because the Ubuntu Server ISO image file has not yet been removed from the virtual DVD drive, you'll most likely get a “Failed” message along with a request to remove the installation medium. Click the X in the VM's upper‐right corner. You'll receive the Close Virtual Machine screen, which looks similar to the following:
Click the circle next to Power Off The Machine.
Click OK to power off the Ubuntu Server virtual machine. At this point, the VirtualBox hypervisor typically automatically removes the ISO image file from the virtual DVD drive for you. But you should check to make sure it is gone.
Click the Settings button in the VirtualBox Manager's top‐right pane, which opens the Settings window for the Ubuntu Server VM.
In the Settings window, click Storage in the left pane to open the Storage settings window for the Ubuntu Server. Here you should see the word Empty in the window's middle pane under the Controller: IDE.
Click OK to return to the VirtualBox Manager window.
Boot up your Ubuntu Server VM by clicking the Start button in the VirtualBox Manager's top‐right pane.
You may see lots of messages go by on your screen. Let the process continue until you reach this window:

Because this first terminal, called tty1, gets messages displayed on it, it's best to jump to a different terminal where you can work in peace.
Press Ctrl+Alt+F2 to reach the tty2 terminal.
In the Username field, type sysadmin and press Enter.
In the Password field, be aware that nothing will show as you type in your password. There are no symbols such as asterisks or dots shown. Type in the password you created for this system earlier, and press Enter.
After you log into the system successfully, you receive a prompt similar to the following:
```
sysadmin@ubuntu-server:~$
```
This prompt is where you enter your commands, and it's called the command‐line interface.

The next several commands assume that your host machine is connected to a network.
As part of the installation process, update the software information by typing sudoapt update, and press Enter. When it asks for a password, type in the same password you used to log into the system.
When you receive a prompt, update the software by typing sudo apt dist‐upgrade, and press Enter. It may ask you for a sudo password, and if it does, type in the same password you used to log into the system.
When the software update process asks “Do you want to continue? [Y/n],” type Y and press Enter.
This software update may take a while, so go get a cup of coffee and check the latest statuses on social media.
When you receive a command‐line prompt, the installation process is complete. Type sudo poweroff at the prompt and press Enter. It may ask you for a sudo password, and if it does, type in the same password you used to log into the system.

Congratulations! You've installed Ubuntu Server as a VM within the VirtualBox hypervisor. Now that the installation process is complete, it's a good idea to check and make sure everything is OK. We'll cover that next.

Checking the Installation

Though the system may appear fine after an initial installation, it's wise to check. It may be tricky to understand everything you are looking at in this section, but reviewing this information will help as we cover these utilities and concepts in detail later in the book. Also, you can return to this section the next time you perform an Ubuntu distribution installation for guidance.

First, boot your Ubuntu Server VM. After the system has booted, log into the tty2 terminal, and do the following:

Check for boot errors. There are three commands that can help you check for boot errors, and none of them requires the sudo command to run. The first is dmesg. This will display the kernel ring buffer, but that data is useful only if you check it soon after the system has booted.
To see boot messages long after a system boot, type less /var/log/bootstrap.log at the prompt and press Enter. You can move forward through this log by pressing the spacebar. When you are done looking at the information, press the Q key to return to the command‐line prompt.

Finally, you can look for boot errors and all kinds of messages via the journalctl command. To peruse this information, you will need to press the spacebar to move forward and then the Q key to quit your viewing.
Determine the default boot level. The default boot level on a Linux system determines what applications are started when the system boots. The command to see this information is systemctl get‐default. It does not require the sudo command to use.
Most likely, you will see graphical.target when you issue this command, meaning that if graphical user interface (GUI) software is available, the GUI will start on bootup. However, on Ubuntu Server, since GUI software is not installed by default, this response from the systemctl get‐default command does not indicate a GUI is provided.
Check version information. Determining the version numbers of the system's main components is helpful when tracking down problems. First, make sure you have the right Ubuntu Server distribution version installed by typing cat /etc/issue at the prompt. The version is in the first few words of the displayed line.
Check the Linux kernel version too. This is important to know because different features (and bugs!) exist in the various kernel versions. To see this information, you need to type uname ‐r at the command‐line prompt. You can also view this information via the cat /proc/version command.

Finally, look at the version of the Bash shell running on the system. This is easy to accomplish with the bash ‐‐version command.

Once you've completed your checks, celebrate! You worked hard to get this Ubuntu Server distribution installed correctly.

The Bottom Line

Review needed Ubuntu server hardware resources. Determining the hardware resources required for an Ubuntu installation on a physical or virtualized server helps to ensure a successful completion of the install. It also avoids wasting time.
- Master It Imagine that you need to install the Ubuntu Server on a physical server that has a dual‐core 1 GHz CPU, a 200 GB hard drive, and 10 GB of RAM. Are the server's resources sufficient? Why or why not?
Determine the requirements for a virtual Ubuntu system. Installing the Ubuntu Server distribution on as a VM on a host system has different requirements than a direct installation on a physical server. It is critical to evaluate the host system so that the installation is successful.
- Master It Your project team is planning on installing two Ubuntu Server VMs on a host system that has a dual‐core 1 GHz CPU, a 200 GB hard drive, and 10 GB of RAM. Are the host system's resources sufficient? Why or why not?
Obtain Ubuntu Server software. To install the Ubuntu Server Linux distribution, you must have the proper ISO image file. This is true whether you are installing it directly on hardware or as a VM. Besides getting the ISO file, you need to ensure that it is not corrupted so that the installation proceeds well.
- Master It You've downloaded the Ubuntu Server ISO image file but are concerned that during the download process, file corruption occurred. What should you do to see whether the ISO image file is corrupt?
Conduct an installation of an Ubuntu Server. There are several steps to successfully install an Ubuntu Server, and it is critical that you complete all of them. Skipping a step can cause problems immediately, and problems later, if you can even get the system to boot.
- Master It Your sysadmin team has correctly installed the Ubuntu Server software from the ISO image file, and the system booted without any problems. What's the next step?
Audit the Ubuntu Server's installation. If you had some problems while booting the system, there are a few commands you can use to look at helpful boot messages. But even a successful installation still requires a few additional checks.
- Master It At your company, you have completed the entire Ubuntu Server installation process on a new system without any problems for the development team. The team wants to know what version of the Linux kernel is used on this new system. How do you get that information?