MQTT on CentOS 10 Stream Installation - Part 01

This instructable will help readers understand the installation, and basic configuration of CentOS Stream 10. It also helps readers with configuring an MQTT broker to capture data from any smart device and analyze it.

The readers can also understand the difference between "Server with GUI" and "Minimal" Installation.

1. A laptop/PC with Microsoft Windows OS
2. VMware Workstation
3. CentOS Stream 10 ISO file downloaded from here. The file size is 6.85 GB. Make sure you have sufficient space on your hard disk.

Note: There must be at least 9 GB of free hard disk space for the "Server with GUI" installation (Screenshot attached). "Minimal Installation" needs 1.4 GB (Screenshot attached).

Following are the steps to complete the initial setup (environment) for installing CentOS Stream 10 Virtual Machine.

1. Open VMware Workstation Application. Note: I have a VM workstation 12 Pro while writing this article. Start creating a new virtual machine by pressing "Ctrl + N"
2. Proceed by selecting "Custom (advanced)"
3. Leave the "Virtual Machine hardware compatibility" to default and continue.
4. Using the "Browse" button select the installer disk (ISO file)
5. Name the virtual machine and set the location of the VM
6. Configure the processor to match your needs. I have selected 2 processors.
7. Configure Memory for the Virtual Machine. I configured it to have 4 B RAM.
8. This VM has to participate in the network, select "Use bridged networking" and proceed.
9. Leave "I/O controller types" to default and continue.
10. Leave the "Virtual disk type" to default and continue.
11. It is now time to configure "Disk". Proceed by selecting "Create a new virtual disk".
12. "Specify Disk Capacity" to your individual needs. I specified the "Maximum disk size" as 18 GB, and selected "Store virtual disk as a single file"
13. Specify the "Disk File". You will have an option to change the name. I left it to default.
14. Please select "Customize Hardware" from the "Ready to Create Virtual Machine" screen and remove what you feel is not necessary for the virtual machine. I removed the "USB Controller, Sound Card, and Printer".
15. Click on "Finis" to complete this step.

VMware "Thin Provisioning" helps you save resource utilization.

This section explains the screens/steps you will come across during the CentOS Stream 10 installation on a VM:

1. On the first screen, you will be prompted with three options:
2. Install CentOS Stream 10 - I selected this option as I used an ISO file and there is nothing to test an ISO file.
3. Test this media and install CentOS Stream 10. This option is necessary when we use physical CD/DVD media.
4. Troubleshooting
5. A welcome screen will appear prompting you to select the installation process language.
6. The "Installation Summary page" is displayed with an exclamation mark on the "Installation Destination". Select it and click on "Done" to proceed further. You can observe the exclamation mark to go. Observe "Software Selection" as "Server with GUI". This installation needs almost 9.0 GB of free space.
7. Select "Root Account" and provide a strong password. It is better to select "Allow root SSH login with password".
8. On completion of the above steps, select "Begin Installation"
9. Approximately 1225 files/packages will be installed.
10. Wait until you are prompted to "REBOOT SYSTEM." Then, click on the button to proceed to the next section.

Explanation of Screenshots will give you all clarity:

1. On successful completion of the OS installation, you will be prompted with a Welcome Screen. I have selected "English - India"
2. In the "Typing" screen I selected "English (India, with rupee)
3. I enabled the "Location Services" in the "Privacy" screen.
4. I entered "Hyderabad" and selected "Hyderabad, Telangana, India" from the list.
5. I entered my "Full Name" in the "About You screen and selected the appropriate user name.
6. I entered a strong password in the "Set a password" screen.
7. I started using CentOS Stream 10.

CentOS Stream 10 Minimal Installation is sufficient for us all to configure it as an MQTT Server. It is simple, less time-consuming, and occupies one-fourth of the hard disk space. This section helps you understand the changes to complete the CentOS Stream 10 Minimal Installation.

The process explained in "Step 1: Virtual Machine Hardware Configuration" remains the same. We need to make only one change during the installation process to complete the "CentOS Stream 10 Minimal Installation".

In the "Installation Summary" screen, you need to select "Minimal Install" in the "Software Selection" section. Please take help from the screenshots for successful installation. The rest procedure (As explained in Step 2: CentOS Stream 10 Installation) remain the same.

The number of packages that get installed is approximately 365 (one-fourth when compared to the "Server with GUI option")

Reboot the machine when prompted.

As shown in the screenshots, on machine reboot, there is a continuous display of a message: "IPV6: MLD clamping QRV from 1 to 2!".

1. Ignoring the message appearance, login to the machine by entering "root" user credentials.
2. Execute: "sysctl net.ipv6.mld_qrv=1"

This will stop the message from reappearing, and help us work with the machine.

The message will reappear every time the OS boots. A screenshot with boot options is provided in this article.

To permanently suppress it, edit the file "/etc/sysctl.d/98-mld_grv.conf" and enter "net.ipv6.mld_qrv=1" in the file. Save and exit. Reboot the machine by executing "init 6" and check.

1. Command to find the IP address.
2. Configuration file to modify parameters to configure Static IP Address.
3. Prerequisites for MQTT Installation
4. MQTT Installation
5. Configuring MQTT to receive data from Smart Devices (User creation)