Virtualization with KVM

• 1: How to Install KVM on AlmaLinux
• 2: How to Create KVM Virtual Machines on AlmaLinux
• 3: How to Create KVM Virtual Machines Using GUI on AlmaLinux
• 4: Basic KVM Virtual Machine Operations on AlmaLinux
• 5: How to Install KVM VM Management Tools on AlmaLinux
• 6: How to Set Up a VNC Connection for KVM on AlmaLinux
• 7: How to Set Up a VNC Client for KVM on AlmaLinux
• 8: How to Enable Nested KVM Settings on AlmaLinux
• 9: How to Make KVM Live Migration on AlmaLinux
• 10: How to Perform KVM Storage Migration on AlmaLinux
• 11: How to Set Up UEFI Boot for KVM Virtual Machines on AlmaLinux
• 12: How to Enable TPM 2.0 on KVM on AlmaLinux
• 13: How to Enable GPU Passthrough on KVM with AlmaLinux
• 14: How to Use VirtualBMC on KVM with AlmaLinux

1 - How to Install KVM on AlmaLinux

How to Install KVM on AlmaLinux: A Step-by-Step Guide

Kernel-based Virtual Machine (KVM) is a robust virtualization technology built into the Linux kernel. With KVM, you can transform your AlmaLinux system into a powerful hypervisor capable of running multiple virtual machines (VMs). Whether you’re setting up a lab, a production environment, or a test bed, KVM is an excellent choice for virtualization.

In this guide, we’ll walk you through the steps to install KVM on AlmaLinux, including configuration, testing, and troubleshooting tips.

What is KVM?

KVM (Kernel-based Virtual Machine) is an open-source hypervisor that allows Linux systems to run VMs. It integrates seamlessly with the Linux kernel, leveraging modern CPU hardware extensions such as Intel VT-x and AMD-V to deliver efficient virtualization.

Key Features of KVM:

• Full virtualization for Linux and Windows guests.
• Scalability and performance for enterprise workloads.
• Integration with tools like Virt-Manager for GUI-based management.

Step 1: Prerequisites

Before installing KVM on AlmaLinux, ensure the following prerequisites are met:

1. Hardware Requirements:

   • A 64-bit CPU with virtualization extensions (Intel VT-x or AMD-V).
   • At least 4 GB of RAM and adequate disk space.

2. Verify Virtualization Support: Use the lscpu command to check if your CPU supports virtualization:

   lscpu | grep Virtualization
   

   Output should indicate VT-x (Intel) or AMD-V (AMD).

   If not, enable virtualization in the BIOS/UEFI settings.

3. Administrative Access:

   • Root or sudo privileges are required.

Step 2: Install KVM and Related Packages

KVM installation involves setting up several components, including the hypervisor itself, libvirt for VM management, and additional tools for usability.

1. Update the System: Begin by updating the system:

   sudo dnf update -y
   

2. Install KVM and Dependencies: Run the following command to install KVM, libvirt, and Virt-Manager:

   sudo dnf install -y qemu-kvm libvirt libvirt-devel virt-install virt-manager
   

3. Enable and Start Libvirt Service: Enable the libvirtd service to start on boot:

   sudo systemctl enable libvirtd
   sudo systemctl start libvirtd
   

4. Verify Installation: Check if KVM modules are loaded:

   lsmod | grep kvm
   

   Output should display kvm_intel (Intel) or kvm_amd (AMD).

Step 3: Configure Network Bridge (Optional)

To allow VMs to connect to external networks, configure a network bridge:

1. Install Bridge Utils:

   sudo dnf install bridge-utils -y
   

2. Create a Bridge Configuration: Edit the network configuration file (replace eth0 with your network interface):

   sudo nano /etc/sysconfig/network-scripts/ifcfg-br0
   

   Add the following content:

   DEVICE=br0
   TYPE=Bridge
   BOOTPROTO=dhcp
   ONBOOT=yes
   

3. Edit the Physical Interface: Update the interface configuration (e.g., /etc/sysconfig/network-scripts/ifcfg-eth0) to link it to the bridge:

   DEVICE=eth0
   TYPE=Ethernet
   BRIDGE=br0
   BOOTPROTO=dhcp
   ONBOOT=yes
   

4. Restart Networking:

   sudo systemctl restart network
   

Step 4: Create Your First Virtual Machine

With KVM installed, you can now create VMs using the virt-install command or Virt-Manager (GUI).

1. Using Virt-Manager (GUI):

   • Launch Virt-Manager:

     virt-manager
     

   • Connect to the local hypervisor and follow the wizard to create a new VM.

2. Using virt-install (Command Line): Create a VM with the following command:

   sudo virt-install \
     --name testvm \
     --ram 2048 \
     --disk path=/var/lib/libvirt/images/testvm.qcow2,size=10 \
     --vcpus 2 \
     --os-type linux \
     --os-variant almalinux8 \
     --network bridge=br0 \
     --graphics none \
     --cdrom /path/to/installer.iso
   

Step 5: Managing Virtual Machines

1. Listing VMs: To see a list of running VMs:

   sudo virsh list
   

2. Starting and Stopping VMs: Start a VM:

   sudo virsh start testvm
   

   Stop a VM:

   sudo virsh shutdown testvm
   

3. Editing VM Configuration: Modify a VM’s settings:

   sudo virsh edit testvm
   

4. Deleting a VM:

   sudo virsh undefine testvm
   sudo rm -f /var/lib/libvirt/images/testvm.qcow2
   

Step 6: Performance Tuning (Optional)

1. Enable Nested Virtualization: Check if nested virtualization is enabled:

   cat /sys/module/kvm_intel/parameters/nested
   

   If disabled, enable it by editing /etc/modprobe.d/kvm.conf:

   options kvm_intel nested=1
   

2. Optimize Disk I/O: Use VirtIO drivers for improved performance when creating VMs:

   --disk path=/var/lib/libvirt/images/testvm.qcow2,bus=virtio
   

3. Allocate Sufficient Resources: Ensure adequate CPU and memory resources for each VM to prevent host overload.

Troubleshooting Common Issues

1. Issue: “KVM Not Supported”

   • Verify virtualization support in the CPU.
   • Enable virtualization in the BIOS/UEFI settings.

2. Issue: “Permission Denied” When Managing VMs

   • Ensure your user is part of the libvirt group:

     sudo usermod -aG libvirt $(whoami)
     

3. Issue: Networking Problems

   • Check firewall settings to ensure proper traffic flow:

     sudo firewall-cmd --add-service=libvirt --permanent
     sudo firewall-cmd --reload
     

Conclusion

Installing KVM on AlmaLinux is a straightforward process that unlocks powerful virtualization capabilities for your system. With its seamless integration into the Linux kernel, KVM provides a reliable and efficient platform for running multiple virtual machines. By following this guide, you can set up KVM, configure networking, and create your first VM in no time.

Whether you’re deploying VMs for development, testing, or production, KVM on AlmaLinux is a robust solution that scales with your needs.

2 - How to Create KVM Virtual Machines on AlmaLinux

How to Create KVM Virtual Machines on AlmaLinux: A Step-by-Step Guide

Kernel-based Virtual Machine (KVM) is one of the most reliable and powerful virtualization solutions available for Linux systems. By using KVM on AlmaLinux, administrators can create and manage virtual machines (VMs) with ease, enabling them to run multiple operating systems simultaneously on a single physical machine.

In this guide, we’ll walk you through the entire process of creating a KVM virtual machine on AlmaLinux. From installation to configuration, we’ll cover everything you need to know to get started with virtualization.

What is KVM?

KVM (Kernel-based Virtual Machine) is a full virtualization solution that transforms a Linux system into a hypervisor. Leveraging the hardware virtualization features of modern CPUs (Intel VT-x or AMD-V), KVM allows users to run isolated VMs with their own operating systems and applications.

Key Features of KVM:

• Efficient Performance: Native virtualization using hardware extensions.
• Flexibility: Supports various guest OSes, including Linux, Windows, and BSD.
• Scalability: Manage multiple VMs on a single host.
• Integration: Seamless management using tools like virsh and virt-manager.

Step 1: Prerequisites

Before creating a virtual machine, ensure your system meets these requirements:

1. System Requirements:

   • A 64-bit processor with virtualization extensions (Intel VT-x or AMD-V).
   • At least 4 GB of RAM (8 GB or more recommended for multiple VMs).
   • Sufficient disk space for hosting VM storage.

2. Verify Virtualization Support: Check if the CPU supports virtualization:

   lscpu | grep Virtualization
   

   If VT-x (Intel) or AMD-V (AMD) appears in the output, your CPU supports virtualization. If not, enable it in the BIOS/UEFI.

3. Installed KVM and Required Tools: KVM and its management tools must already be installed. If not, follow our guide on How to Install KVM on AlmaLinux.

Step 2: Preparing the Environment

Before creating a virtual machine, ensure your KVM environment is ready:

1. Start and Enable Libvirt:

   sudo systemctl enable libvirtd
   sudo systemctl start libvirtd
   

2. Check Virtualization Modules: Ensure KVM modules are loaded:

   lsmod | grep kvm
   

   Look for kvm_intel or kvm_amd.

3. Download the Installation Media: Download the ISO file of the operating system you want to install. For example:

   • AlmaLinux: Download ISO

Step 3: Creating a KVM Virtual Machine Using Virt-Manager (GUI)

Virt-Manager is a graphical tool that simplifies VM creation and management.

1. Launch Virt-Manager: Install and start Virt-Manager:

   sudo dnf install virt-manager -y
   virt-manager
   

2. Connect to the Hypervisor: In the Virt-Manager interface, connect to the local hypervisor (usually listed as QEMU/KVM).

3. Start the New VM Wizard:

   • Click Create a New Virtual Machine.
   • Select Local install media (ISO image or CDROM) and click Forward.

4. Choose Installation Media:

   • Browse and select the ISO file of your desired operating system.
   • Choose the OS variant (e.g., AlmaLinux or CentOS).

5. Allocate Resources:

   • Assign memory (RAM) and CPU cores to the VM.
   • For example, allocate 2 GB RAM and 2 CPU cores for a lightweight VM.

6. Create a Virtual Disk:

   • Specify the storage size for the VM (e.g., 20 GB).
   • Choose the storage format (e.g., qcow2 for efficient storage).

7. Network Configuration:

   • Use the default network bridge (NAT) for internet access.
   • For advanced setups, configure a custom bridge.

8. Finalize and Start Installation:

   • Review the VM settings.
   • Click Finish to start the VM and launch the OS installer.

Step 4: Creating a KVM Virtual Machine Using Virt-Install (CLI)

For users who prefer the command line, the virt-install utility is an excellent choice.

1. Create a Virtual Disk:

   sudo qemu-img create -f qcow2 /var/lib/libvirt/images/testvm.qcow2 20G
   

2. Run Virt-Install: Execute the following command to create and start the VM:

   sudo virt-install \
     --name testvm \
     --ram 2048 \
     --vcpus 2 \
     --disk path=/var/lib/libvirt/images/testvm.qcow2,size=20 \
     --os-type linux \
     --os-variant almalinux8 \
     --network bridge=virbr0 \
     --graphics vnc \
     --cdrom /path/to/almalinux.iso
   

   Replace /path/to/almalinux.iso with the path to your ISO file.

3. Access the VM Console: Use virsh or a VNC viewer to access the VM:

   sudo virsh list
   sudo virsh console testvm
   

Step 5: Managing Virtual Machines

After creating a VM, use these commands to manage it:

1. List Running VMs:

   sudo virsh list
   

2. Start or Stop a VM:

   • Start:

     sudo virsh start testvm
     

   • Stop:

     sudo virsh shutdown testvm
     

3. Edit VM Configuration: Modify settings such as CPU or memory allocation:

   sudo virsh edit testvm
   

4. Delete a VM: Undefine and remove the VM:

   sudo virsh undefine testvm
   sudo rm -f /var/lib/libvirt/images/testvm.qcow2
   

Step 6: Troubleshooting Common Issues

1. Issue: “KVM Not Found”:

   • Ensure the KVM modules are loaded:

     sudo modprobe kvm
     

2. Issue: Virtual Machine Won’t Start:

   • Check system logs for errors:

     sudo journalctl -xe
     

3. Issue: No Internet Access for the VM:

   • Ensure the virbr0 network is active:

     sudo virsh net-list
     

4. Issue: Poor VM Performance:

   • Enable nested virtualization:

     echo "options kvm_intel nested=1" | sudo tee /etc/modprobe.d/kvm.conf
     sudo modprobe -r kvm_intel
     sudo modprobe kvm_intel
     

Conclusion

Creating a KVM virtual machine on AlmaLinux is a straightforward process that can be accomplished using either a graphical interface or command-line tools. With KVM, you can efficiently manage resources, deploy test environments, or build a virtualization-based infrastructure for your applications.

By following this guide, you now have the knowledge to create and manage VMs using Virt-Manager or virt-install, troubleshoot common issues, and optimize performance for your virtualization needs.

Start building your virtualized environment with KVM today and unlock the potential of AlmaLinux for scalable and reliable virtualization.

3 - How to Create KVM Virtual Machines Using GUI on AlmaLinux

How to Create KVM Virtual Machines Using GUI on AlmaLinux

Kernel-based Virtual Machine (KVM) is a powerful and efficient virtualization technology available on Linux. While KVM provides robust command-line tools for managing virtual machines (VMs), not everyone is comfortable working exclusively with a terminal. Fortunately, tools like Virt-Manager offer a user-friendly graphical user interface (GUI) to create and manage VMs on AlmaLinux.

In this guide, we’ll walk you through the step-by-step process of creating KVM virtual machines on AlmaLinux using a GUI, from installing the necessary tools to configuring and launching your first VM.

Why Use Virt-Manager for KVM?

Virt-Manager (Virtual Machine Manager) simplifies the process of managing KVM virtual machines. It provides a clean interface for tasks like:

• Creating Virtual Machines: A step-by-step wizard for creating VMs.
• Managing Resources: Allocate CPU, memory, and storage for your VMs.
• Monitoring Performance: View real-time CPU, memory, and network statistics.
• Network Configuration: Easily manage NAT, bridged, or isolated networking.

Step 1: Prerequisites

Before you start, ensure the following requirements are met:

1. System Requirements:

   • AlmaLinux 8 or later.
   • A 64-bit processor with virtualization support (Intel VT-x or AMD-V).
   • At least 4 GB of RAM and adequate disk space.

2. Verify Virtualization Support: Check if your CPU supports virtualization:

   lscpu | grep Virtualization
   

   Ensure virtualization is enabled in the BIOS/UEFI settings if the above command does not show VT-x (Intel) or AMD-V (AMD).

3. Administrative Access: Root or sudo access is required to install and configure the necessary packages.

Step 2: Install KVM and Virt-Manager

To create and manage KVM virtual machines using a GUI, you need to install KVM, Virt-Manager, and related packages.

1. Update Your System: Run the following command to ensure your system is up to date:

   sudo dnf update -y
   

2. Install KVM and Virt-Manager: Install the required packages:

   sudo dnf install -y qemu-kvm libvirt libvirt-devel virt-install virt-manager
   

3. Start and Enable Libvirt: Enable the libvirt service to start at boot and launch it immediately:

   sudo systemctl enable libvirtd
   sudo systemctl start libvirtd
   

4. Verify Installation: Check if the KVM modules are loaded:

   lsmod | grep kvm
   

   You should see kvm_intel (for Intel CPUs) or kvm_amd (for AMD CPUs).

Step 3: Launch Virt-Manager

1. Start Virt-Manager: Open Virt-Manager by running the following command:

   virt-manager
   

   Alternatively, search for “Virtual Machine Manager” in your desktop environment’s application menu.

2. Connect to the Hypervisor: When Virt-Manager launches, it automatically connects to the local hypervisor (QEMU/KVM). If it doesn’t, click File > Add Connection, select QEMU/KVM, and click Connect.

Step 4: Create a Virtual Machine Using Virt-Manager

Now that the environment is set up, let’s create a new virtual machine.

1. Start the New Virtual Machine Wizard:

   • In the Virt-Manager interface, click the Create a new virtual machine button.

2. Choose Installation Method:

   • Select Local install media (ISO image or CDROM) and click Forward.

3. Provide Installation Media:

   • Click Browse to locate the ISO file of the operating system you want to install (e.g., AlmaLinux, CentOS, or Ubuntu).
   • Virt-Manager may automatically detect the OS variant based on the ISO. If not, manually select the appropriate OS variant.

4. Allocate Memory and CPUs:

   • Assign resources for the VM. For example:
     • Memory: 2048 MB (2 GB) for lightweight VMs.
     • CPUs: 2 for balanced performance.
   • Adjust these values based on your host system’s available resources.

5. Create a Virtual Disk:

   • Set the size of the virtual disk (e.g., 20 GB).
   • Choose the disk format. qcow2 is recommended for efficient storage.

6. Configure Network:

   • By default, Virt-Manager uses NAT for networking, allowing the VM to access external networks through the host.
   • For more advanced setups, you can use a bridged or isolated network.

7. Finalize the Setup:

   • Review the VM configuration and make any necessary changes.
   • Click Finish to create the VM and launch the installation process.

Step 5: Install the Operating System on the Virtual Machine

1. Follow the OS Installation Wizard:

   • Once the VM is launched, it will boot from the ISO file, starting the operating system installation process.
   • Follow the on-screen instructions to install the OS.

2. Set Up Storage and Network:

   • During the installation, configure storage partitions and network settings as required.

3. Complete the Installation:

   • After the installation finishes, remove the ISO from the VM to prevent it from booting into the installer again.
   • Restart the VM to boot into the newly installed operating system.

Step 6: Managing the Virtual Machine

After creating the virtual machine, you can manage it using Virt-Manager:

1. Starting and Stopping VMs:

   • Start a VM by selecting it in Virt-Manager and clicking Run.
   • Shut down or suspend the VM using the Pause or Shut Down buttons.

2. Editing VM Settings:

   • To modify CPU, memory, or storage settings, right-click the VM in Virt-Manager and select Open or Details.

3. Deleting a VM:

   • To delete a VM, right-click it in Virt-Manager and select Delete. Ensure you also delete associated disk files if no longer needed.

Step 7: Advanced Features

1. Using Snapshots:

   • Snapshots allow you to save the state of a VM and revert to it later. In Virt-Manager, go to the Snapshots tab and click Take Snapshot.

2. Network Customization:

   • For advanced networking, configure bridges or isolated networks using the Edit > Connection Details menu.

3. Performance Optimization:

   • Use VirtIO drivers for improved disk and network performance.

Step 8: Troubleshooting Common Issues

1. Issue: “KVM Not Found”:

   • Ensure the KVM modules are loaded:

     sudo modprobe kvm
     

2. Issue: Virtual Machine Won’t Start:

   • Check for errors in the system log:

     sudo journalctl -xe
     

3. Issue: Network Not Working:

   • Verify that the virbr0 interface is active:

     sudo virsh net-list
     

4. Issue: Poor Performance:

   • Ensure the VM uses VirtIO for disk and network devices for optimal performance.

Conclusion

Creating KVM virtual machines using a GUI on AlmaLinux is an intuitive process with Virt-Manager. This guide has shown you how to install the necessary tools, configure the environment, and create your first VM step-by-step. Whether you’re setting up a development environment or exploring virtualization, Virt-Manager simplifies KVM management and makes it accessible for users of all experience levels.

By following this guide, you can confidently create and manage virtual machines on AlmaLinux using the GUI. Start leveraging KVM’s power and flexibility today!

4 - Basic KVM Virtual Machine Operations on AlmaLinux

How to Perform Basic Operations on KVM Virtual Machines in AlmaLinux

Kernel-based Virtual Machine (KVM) is a powerful open-source virtualization platform that transforms AlmaLinux into a robust hypervisor capable of running multiple virtual machines (VMs). Whether you’re managing a home lab or an enterprise environment, understanding how to perform basic operations on KVM VMs is crucial for smooth system administration.

In this guide, we’ll cover essential operations for KVM virtual machines on AlmaLinux, including starting, stopping, managing storage, networking, snapshots, and troubleshooting common issues.

Why Choose KVM on AlmaLinux?

KVM’s integration into the Linux kernel makes it one of the most efficient and reliable virtualization solutions available. By running KVM on AlmaLinux, users benefit from a stable, enterprise-grade operating system and robust hypervisor capabilities.

Key advantages include:

• Native performance for VMs.
• Comprehensive management tools like virsh (CLI) and Virt-Manager (GUI).
• Scalability and flexibility for diverse workloads.

Prerequisites

Before managing KVM VMs, ensure your environment is set up:

1. KVM Installed:

   • KVM and required tools like libvirt and Virt-Manager should be installed. Refer to our guide on Installing KVM on AlmaLinux.

2. Virtual Machines Created:

   • At least one VM must already exist. If not, refer to our guide on Creating KVM Virtual Machines.

3. Access:

   • Root or sudo privileges on the host system.

Step 1: Start and Stop Virtual Machines

Managing VM power states is one of the fundamental operations.

Using virsh (Command Line Interface)

1. List Available VMs: To see all VMs:

   sudo virsh list --all
   

   Output:

   Id   Name      State
   -------------------------
   -    testvm    shut off
   

2. Start a VM:

   sudo virsh start testvm
   

3. Stop a VM: Gracefully shut down the VM:

   sudo virsh shutdown testvm
   

4. Force Stop a VM: If the VM doesn’t respond to shutdown:

   sudo virsh destroy testvm
   

Using Virt-Manager (GUI)

1. Launch Virt-Manager:

   virt-manager
   

2. Select the VM, then click Start to boot it or Shut Down to power it off.

Step 2: Access the VM Console

Using virsh

To access the VM console via CLI:

sudo virsh console testvm

To exit the console, press Ctrl+].

Using Virt-Manager

In Virt-Manager, right-click the VM and select Open, then interact with the VM via the graphical console.

Step 3: Manage VM Resources

As workloads evolve, you may need to adjust VM resources like CPU, memory, and disk.

Adjust CPU and Memory

Using virsh:

1. Edit the VM configuration:

   sudo virsh edit testvm
   

2. Modify <memory> and <vcpu> values:

   <memory unit='MiB'>2048</memory>
   <vcpu placement='static'>2</vcpu>
   

Using Virt-Manager:

1. Right-click the VM, select Details, and navigate to the Memory or Processors tabs.
2. Adjust the values and save changes.

Expand Virtual Disk

Using qemu-img:

1. Resize the disk:

   sudo qemu-img resize /var/lib/libvirt/images/testvm.qcow2 +10G
   

2. Resize the partition inside the VM using a partition manager.

Step 4: Manage VM Networking

List Available Networks

sudo virsh net-list --all

Attach a Network to a VM

1. Edit the VM:

   sudo virsh edit testvm
   

2. Add a <interface> section:

   <interface type='network'>
     <source network='default'/>
   </interface>
   

Using Virt-Manager

1. Open the VM’s details, then navigate to the NIC section.
2. Choose a network (e.g., NAT, Bridged) and save changes.

Step 5: Snapshots

Snapshots capture the state of a VM at a particular moment, allowing you to revert changes if needed.

Create a Snapshot

Using virsh:

sudo virsh snapshot-create-as testvm snapshot1 "Initial snapshot"

Using Virt-Manager:

1. Open the VM, go to the Snapshots tab.
2. Click Take Snapshot, provide a name, and save.

List Snapshots

sudo virsh snapshot-list testvm

Revert to a Snapshot

sudo virsh snapshot-revert testvm snapshot1

Step 6: Backup and Restore VMs

Backup a VM

Export the VM to an XML file:

sudo virsh dumpxml testvm > testvm.xml

Backup the disk image:

sudo cp /var/lib/libvirt/images/testvm.qcow2 /backup/testvm.qcow2

Restore a VM

1. Recreate the VM from the XML file:

   sudo virsh define testvm.xml
   

2. Restore the disk image to its original location.

Step 7: Troubleshooting Common Issues

1. Issue: VM Won’t Start

   • Check logs for errors:

     sudo journalctl -xe
     

   • Verify resources (CPU, memory, disk).

2. Issue: Network Connectivity Issues

   • Ensure the network is active:

     sudo virsh net-list
     

   • Restart the network:

     sudo virsh net-start default
     

3. Issue: Disk Space Exhaustion

   • Check disk usage:

     df -h
     

   • Expand storage or move disk images to a larger volume.

Step 8: Monitoring Virtual Machines

Use virt-top to monitor resource usage:

sudo virt-top

In Virt-Manager, select a VM and view real-time statistics for CPU, memory, and disk.

Conclusion

Managing KVM virtual machines on AlmaLinux is straightforward once you master basic operations like starting, stopping, resizing, networking, and snapshots. Tools like virsh and Virt-Manager provide both flexibility and convenience, making KVM an ideal choice for virtualization.

With this guide, you can confidently handle routine tasks and ensure your virtualized environment operates smoothly. Whether you’re hosting development environments, testing applications, or running production workloads, KVM on AlmaLinux is a powerful solution.

5 - How to Install KVM VM Management Tools on AlmaLinux

How to Install KVM VM Management Tools on AlmaLinux: A Complete Guide

Kernel-based Virtual Machine (KVM) is a robust virtualization platform available in Linux. While KVM is powerful, managing virtual machines (VMs) efficiently requires specialized tools. AlmaLinux, being an enterprise-grade Linux distribution, provides several tools to simplify the process of creating, managing, and monitoring KVM virtual machines.

In this guide, we’ll explore the installation and setup of KVM VM management tools on AlmaLinux. Whether you prefer a graphical user interface (GUI) or command-line interface (CLI), this post will help you get started.

Why Use KVM Management Tools?

KVM management tools offer a user-friendly way to handle complex virtualization tasks, making them accessible to both seasoned administrators and newcomers. Here’s what they bring to the table:

• Simplified VM Creation: Step-by-step wizards for creating VMs.
• Resource Management: Tools to allocate and monitor CPU, memory, and disk usage.
• Snapshots and Backups: Easy ways to create and revert snapshots.
• Remote Management: Manage VMs from a central system.

Step 1: Prerequisites

Before installing KVM management tools, ensure the following prerequisites are met:

1. System Requirements:

   • AlmaLinux 8 or later.
   • A 64-bit processor with virtualization support (Intel VT-x or AMD-V).
   • Sufficient RAM (4 GB or more recommended) and disk space.

2. KVM Installed:

   • KVM, libvirt, and QEMU must be installed and running. Follow our guide on Installing KVM on AlmaLinux.

3. Administrative Access:

   • Root or sudo privileges are required.

4. Network Connectivity:

   • Ensure the system has a stable internet connection to download packages.

Step 2: Install Core KVM Management Tools

1. Install Libvirt

Libvirt is a key component for managing KVM virtual machines. It provides a unified interface for interacting with the virtualization layer.

Install Libvirt using the following command:

sudo dnf install -y libvirt libvirt-devel

Start and enable the libvirt service:

sudo systemctl enable libvirtd
sudo systemctl start libvirtd

Verify that libvirt is running:

sudo systemctl status libvirtd

2. Install Virt-Manager (GUI Tool)

Virt-Manager (Virtual Machine Manager) is a GUI application for managing KVM virtual machines. It simplifies the process of creating and managing VMs.

Install Virt-Manager:

sudo dnf install -y virt-manager

Launch Virt-Manager from the terminal:

virt-manager

Alternatively, search for “Virtual Machine Manager” in your desktop environment’s application menu.

3. Install Virt-Install (CLI Tool)

Virt-Install is a command-line utility for creating VMs. It is especially useful for automation and script-based management.

Install Virt-Install:

sudo dnf install -y virt-install

Step 3: Optional Management Tools

1. Cockpit (Web Interface)

Cockpit provides a modern web interface for managing Linux systems, including KVM virtual machines.

Install Cockpit:

sudo dnf install -y cockpit cockpit-machines

Start and enable the Cockpit service:

sudo systemctl enable --now cockpit.socket

Access Cockpit in your browser by navigating to:

https://<server-ip>:9090

Log in with your system credentials and navigate to the Virtual Machines tab.

2. Virt-Top (Resource Monitoring)

Virt-Top is a CLI-based tool for monitoring the performance of VMs, similar to top.

Install Virt-Top:

sudo dnf install -y virt-top

Run Virt-Top:

sudo virt-top

3. Kimchi (Web-Based Management)

Kimchi is an open-source, HTML5-based management tool for KVM. It provides an easy-to-use web interface for managing VMs.

Install Kimchi and dependencies:

sudo dnf install -y kimchi

Start the Kimchi service:

sudo systemctl enable --now kimchid

Access Kimchi at:

https://<server-ip>:8001

Step 4: Configure User Access

By default, only the root user can manage VMs. To allow non-root users access, add them to the libvirt group:

sudo usermod -aG libvirt $(whoami)

Log out and back in for the changes to take effect.

Step 5: Create a Test Virtual Machine

After installing the tools, create a test VM to verify the setup.

Using Virt-Manager (GUI)

1. Launch Virt-Manager:

   virt-manager
   

2. Click Create a New Virtual Machine.

3. Select the Local install media (ISO image) option.

4. Choose the ISO file of your preferred OS.

5. Allocate resources (CPU, memory, disk).

6. Configure networking.

7. Complete the setup and start the VM.

Using Virt-Install (CLI)

Run the following command to create a VM:

sudo virt-install \
  --name testvm \
  --ram 2048 \
  --vcpus 2 \
  --disk path=/var/lib/libvirt/images/testvm.qcow2,size=20 \
  --os-variant almalinux8 \
  --cdrom /path/to/almalinux.iso

Replace /path/to/almalinux.iso with the path to your OS ISO.

Step 6: Manage and Monitor Virtual Machines

Start, Stop, and Restart VMs

Using virsh (CLI):

sudo virsh list --all       # List all VMs
sudo virsh start testvm     # Start a VM
sudo virsh shutdown testvm  # Stop a VM
sudo virsh reboot testvm    # Restart a VM

Using Virt-Manager (GUI):

• Select a VM and click Run, Shut Down, or Reboot.

Monitor Resource Usage

Using Virt-Top:

sudo virt-top

Using Cockpit:

• Navigate to the Virtual Machines tab to monitor performance metrics.

Troubleshooting Common Issues

1. Issue: “KVM Not Found”

   • Ensure the KVM modules are loaded:

     sudo modprobe kvm
     

2. Issue: Libvirt Service Fails to Start

   • Check logs for errors:

     sudo journalctl -xe
     

3. Issue: VM Creation Fails

   • Verify that your system has enough resources (CPU, RAM, and disk space).
   • Check the permissions of your ISO file or disk image.

Conclusion

Installing KVM VM management tools on AlmaLinux is a straightforward process that greatly enhances your ability to manage virtual environments. Whether you prefer graphical interfaces like Virt-Manager and Cockpit or command-line utilities like virsh and Virt-Install, AlmaLinux provides the flexibility to meet your needs.

By following this guide, you’ve set up essential tools to create, manage, and monitor KVM virtual machines effectively. These tools empower you to leverage the full potential of virtualization on AlmaLinux, whether for development, testing, or production workloads.

6 - How to Set Up a VNC Connection for KVM on AlmaLinux

How to Set Up a VNC Connection for KVM on AlmaLinux: A Step-by-Step Guide

Virtual Network Computing (VNC) is a popular protocol that allows you to remotely access and control virtual machines (VMs) hosted on a Kernel-based Virtual Machine (KVM) hypervisor. By setting up a VNC connection on AlmaLinux, you can manage your VMs from anywhere with a graphical interface, making it easier to configure, monitor, and control virtualized environments.

In this guide, we’ll walk you through the process of configuring a VNC connection for KVM on AlmaLinux, ensuring you have seamless remote access to your virtual machines.

Why Use VNC for KVM?

VNC provides a straightforward way to interact with virtual machines hosted on KVM. Unlike SSH, which is command-line-based, VNC offers a graphical user interface (GUI) that mimics physical access to a machine.

Benefits of VNC with KVM:

1. Access VMs with a graphical desktop environment.
2. Perform tasks such as OS installation, configuration, and application testing.
3. Manage VMs remotely from any device with a VNC client.

Step 1: Prerequisites

Before starting, ensure the following prerequisites are met:

1. KVM Installed:

   • KVM, QEMU, and libvirt must be installed and running on AlmaLinux. Follow our guide on How to Install KVM on AlmaLinux if needed.

2. VNC Viewer Installed:

   • Install a VNC viewer on your client machine (e.g., TigerVNC, RealVNC, or TightVNC).

3. Administrative Access:

   • Root or sudo privileges on the host machine.

4. Network Setup:

   • Ensure the host and client machines are connected to the same network or the host is accessible via its public IP.

Step 2: Configure KVM for VNC Access

By default, KVM provides VNC access to its virtual machines. This requires enabling and configuring VNC in the VM settings.

1. Verify VNC Dependencies

Ensure qemu-kvm and libvirt are installed:

sudo dnf install -y qemu-kvm libvirt libvirt-devel

Start and enable the libvirt service:

sudo systemctl enable libvirtd
sudo systemctl start libvirtd

Step 3: Enable VNC for a Virtual Machine

You can configure VNC access for a VM using either Virt-Manager (GUI) or virsh (CLI).

Using Virt-Manager (GUI)

1. Launch Virt-Manager:

   virt-manager
   

2. Open the VM’s settings:

   • Right-click the VM and select Open.
   • Go to the Display section.

3. Ensure the VNC protocol is selected under the Graphics tab.

4. Configure the port:

   • Leave the port set to Auto (recommended) or specify a fixed port for easier connection.

5. Save the settings and restart the VM.

Using virsh (CLI)

1. Edit the VM configuration:

   sudo virsh edit <vm-name>
   

2. Locate the <graphics> section and ensure it is configured for VNC:

   <graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0'>
     <listen type='address' address='0.0.0.0'/>
   </graphics>
   

   • port='-1': Automatically assigns an available VNC port.
   • listen='0.0.0.0': Allows connections from any network interface.

3. Save the changes and restart the VM:

   sudo virsh destroy <vm-name>
   sudo virsh start <vm-name>
   

Step 4: Configure the Firewall

Ensure your firewall allows incoming VNC connections (default port range: 5900-5999).

1. Add the firewall rule:

   sudo firewall-cmd --add-service=vnc-server --permanent
   sudo firewall-cmd --reload
   

2. Verify the firewall rules:

   sudo firewall-cmd --list-all
   

Step 5: Connect to the VM Using a VNC Viewer

Once the VM is configured for VNC, you can connect to it using a VNC viewer.

Identify the VNC Port

1. Use virsh to check the VNC display port:

   sudo virsh vncdisplay <vm-name>
   

   Example output:

   :1
   

   The display :1 corresponds to VNC port 5901.

Use a VNC Viewer

1. Open your VNC viewer application on the client machine.
2. Enter the connection details:
   • Host: IP address of the KVM host (e.g., 192.168.1.100).
   • Port: VNC port (5901 for :1).
   • Full connection string example: 192.168.1.100:5901.
3. Authenticate if required and connect to the VM.

Step 6: Secure the VNC Connection

For secure environments, you can tunnel VNC traffic over SSH to prevent unauthorized access.

1. Create an SSH Tunnel

On the client machine, set up an SSH tunnel to the host:

ssh -L 5901:localhost:5901 user@<host-ip>

2. Connect via VNC

Point your VNC viewer to localhost:5901 instead of the host IP.

Step 7: Troubleshooting Common Issues

1. Issue: “Unable to Connect to VNC Server”

   • Ensure the VM is running:

     sudo virsh list --all
     

   • Verify the firewall rules are correct:

     sudo firewall-cmd --list-all
     

2. Issue: “Connection Refused”

   • Check if the VNC port is open:

     sudo netstat -tuln | grep 59
     

   • Verify the listen setting in the <graphics> section of the VM configuration.

3. Issue: Slow Performance

   • Ensure the network connection between the host and client is stable.
   • Use a lighter desktop environment on the VM for better responsiveness.

4. Issue: “Black Screen” on VNC Viewer

   • Ensure the VM has a running graphical desktop environment (e.g., GNOME, XFCE).
   • Verify the guest drivers are installed.

Step 8: Advanced Configuration

For larger environments, consider using advanced tools:

1. Cockpit with Virtual Machines Plugin:

   • Install Cockpit for web-based VM management:

     sudo dnf install cockpit cockpit-machines
     sudo systemctl enable --now cockpit.socket
     

   • Access Cockpit at https://<host-ip>:9090.

2. Custom VNC Ports:

   • Assign static VNC ports to specific VMs for better organization.

Conclusion

Setting up a VNC connection for KVM virtual machines on AlmaLinux is a practical way to manage virtual environments with a graphical interface. By following the steps outlined in this guide, you can enable VNC access, configure your firewall, and securely connect to your VMs from any location.

Whether you’re a beginner or an experienced sysadmin, this guide equips you with the knowledge to efficiently manage KVM virtual machines on AlmaLinux. Embrace the power of VNC for streamlined virtualization management today.

7 - How to Set Up a VNC Client for KVM on AlmaLinux

How to Set Up a VNC Connection Client for KVM on AlmaLinux: A Comprehensive Guide

Virtual Network Computing (VNC) is a powerful protocol that allows users to remotely access and control virtual machines (VMs) hosted on a Kernel-based Virtual Machine (KVM) hypervisor. By configuring a VNC client on AlmaLinux, you can remotely manage VMs with a graphical interface, making it ideal for both novice and experienced users.

This guide provides a detailed walkthrough on setting up a VNC connection client for KVM on AlmaLinux, from installation to configuration and troubleshooting.

Why Use a VNC Client for KVM?

A VNC client enables you to access and interact with virtual machines as if you were directly connected to them. This is especially useful for tasks like installing operating systems, managing graphical applications, or troubleshooting guest environments.

Benefits of a VNC Client for KVM:

• Access VMs with a full graphical interface.
• Perform administrative tasks remotely.
• Simplify interaction with guest operating systems.
• Manage multiple VMs from a single interface.

Step 1: Prerequisites

Before setting up a VNC client for KVM on AlmaLinux, ensure the following prerequisites are met:

1. Host Setup:

   • A KVM hypervisor is installed and configured on the host system.
   • The virtual machine you want to access is configured to use VNC. (Refer to our guide on Setting Up VNC for KVM on AlmaLinux.)

2. Client System:

   • Access to a system where you’ll install the VNC client.
   • A stable network connection to the KVM host.

3. Network Configuration:

   • The firewall on the KVM host must allow VNC connections (default port range: 5900–5999).

Step 2: Install a VNC Client on AlmaLinux

There are several VNC client applications available. Here, we’ll cover the installation of TigerVNC and Remmina, two popular choices.

Option 1: Install TigerVNC

TigerVNC is a lightweight, easy-to-use VNC client.

1. Install TigerVNC:

   sudo dnf install -y tigervnc
   

2. Verify the installation:

   vncviewer --version
   

Option 2: Install Remmina

Remmina is a versatile remote desktop client that supports multiple protocols, including VNC and RDP.

1. Install Remmina and its plugins:

   sudo dnf install -y remmina remmina-plugins-vnc
   

2. Launch Remmina:

   remmina
   

Step 3: Configure VNC Access to KVM Virtual Machines

1. Identify the VNC Port

To connect to a specific VM, you need to know its VNC display port.

1. Use virsh to find the VNC port:

   sudo virsh vncdisplay <vm-name>
   

   Example output:

   :1
   

2. Calculate the VNC port:

   • Add the display number (:1) to the default VNC base port (5900).
   • Example: 5900 + 1 = 5901.

2. Check the Host’s IP Address

On the KVM host, find the IP address to use for the VNC connection:

ip addr

Example output:

192.168.1.100

Step 4: Connect to the VM Using a VNC Client

Using TigerVNC

1. Launch TigerVNC:

   vncviewer
   

2. Enter the VNC server address:

   • Format: <host-ip>:<port>.
   • Example: 192.168.1.100:5901.

3. Click Connect. If authentication is enabled, provide the required password.

Using Remmina

1. Open Remmina.
2. Create a new connection:
   • Protocol: VNC.
   • Server: <host-ip>:<port>.
   • Example: 192.168.1.100:5901.
3. Save the connection and click Connect.

Step 5: Secure the VNC Connection

By default, VNC connections are not encrypted. To secure your connection, use SSH tunneling.

Set Up SSH Tunneling

1. On the client machine, create an SSH tunnel:

   ssh -L 5901:localhost:5901 user@192.168.1.100
   

   • Replace user with your username on the KVM host.
   • Replace 192.168.1.100 with the KVM host’s IP address.

2. Point the VNC client to localhost:5901 instead of the host IP.

Step 6: Troubleshooting Common Issues

1. Unable to Connect to VNC Server

• Verify the VM is running:

  sudo virsh list --all
  

• Check the firewall rules on the host:

  sudo firewall-cmd --list-all
  

2. Incorrect VNC Port

• Ensure the correct port is being used:

  sudo virsh vncdisplay <vm-name>
  

3. Black Screen

• Ensure the VM is running a graphical desktop environment.

• Verify the VNC server configuration in the VM’s <graphics> section:

  <graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0'>
  

4. Connection Timeout

• Check if the VNC server is listening on the expected port:

  sudo netstat -tuln | grep 59
  

Step 7: Advanced Configuration

Set a Password for VNC Connections

1. Edit the VM configuration:

   sudo virsh edit <vm-name>
   

2. Add a <password> element under the <graphics> section:

   <graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0' passwd='yourpassword'/>
   

Use Cockpit for GUI Management

Cockpit provides a modern web interface for managing VMs with integrated VNC.

1. Install Cockpit:

   sudo dnf install cockpit cockpit-machines -y
   

2. Start Cockpit:

   sudo systemctl enable --now cockpit.socket
   

3. Access Cockpit: Navigate to https://<host-ip>:9090 in a browser, log in, and use the Virtual Machines tab.

Conclusion

Setting up a VNC client for KVM on AlmaLinux is an essential skill for managing virtual machines remotely. Whether you use TigerVNC, Remmina, or a web-based tool like Cockpit, VNC offers a flexible and user-friendly way to interact with your VMs.

This guide has provided a step-by-step approach to installing and configuring a VNC client, connecting to KVM virtual machines, and securing your connections. By mastering these techniques, you can efficiently manage virtual environments from any location.

8 - How to Enable Nested KVM Settings on AlmaLinux

Introduction

As virtualization gains momentum in modern IT environments, Kernel-based Virtual Machine (KVM) is a go-to choice for developers and administrators managing virtualized systems. AlmaLinux, a robust CentOS alternative, provides an ideal environment for setting up and configuring KVM. One powerful feature of KVM is nested virtualization, which allows you to run virtual machines (VMs) inside other VMs—a feature vital for testing, sandboxing, or multi-layered development environments.

In this guide, we will explore how to enable nested KVM settings on AlmaLinux. We’ll cover prerequisites, step-by-step instructions, and troubleshooting tips to ensure a smooth configuration.

What is Nested Virtualization?

Nested virtualization enables a VM to act as a hypervisor, running other VMs within it. This setup is commonly used for:

• Testing hypervisor configurations without needing physical hardware.
• Training and development, where multiple VM environments simulate real-world scenarios.
• Software development and CI/CD pipelines that involve multiple virtual environments.

KVM’s nested feature is hardware-dependent, requiring specific CPU support for virtualization extensions like Intel VT-x or AMD-V.

Prerequisites

Before diving into the configuration, ensure the following requirements are met:

1. Hardware Support:

   • A processor with hardware virtualization extensions (Intel VT-x or AMD-V).
   • Nested virtualization capability enabled in the BIOS/UEFI.

2. Operating System:

   • AlmaLinux 8 or newer.
   • The latest kernel version for better compatibility.

3. Packages:

   • KVM modules installed (kvm and qemu-kvm).
   • Virtualization management tools (virt-manager, libvirt).

4. Permissions:

   • Administrative privileges to edit kernel modules and configurations.

Step-by-Step Guide to Enable Nested KVM on AlmaLinux

Step 1: Verify Virtualization Support

Confirm your processor supports virtualization and nested capabilities:

grep -E "vmx|svm" /proc/cpuinfo

• Output Explanation:
  • vmx: Indicates Intel VT-x support.
  • svm: Indicates AMD-V support.

If neither appears, check your BIOS/UEFI settings to enable hardware virtualization.

Step 2: Install Required Packages

Ensure you have the necessary virtualization tools:

sudo dnf install qemu-kvm libvirt virt-manager -y

• qemu-kvm: Provides the KVM hypervisor.
• libvirt: Manages virtual machines.
• virt-manager: Offers a graphical interface to manage VMs.

Enable and start the libvirtd service:

sudo systemctl enable --now libvirtd

Step 3: Check and Load KVM Modules

Verify that the KVM modules are loaded:

lsmod | grep kvm

• kvm_intel or kvm_amd should be listed, depending on your processor type.

If not, load the appropriate module:

sudo modprobe kvm_intel    # For Intel processors
sudo modprobe kvm_amd      # For AMD processors

Step 4: Enable Nested Virtualization

Edit the KVM module options to enable nested support.

For Intel processors:

sudo echo "options kvm_intel nested=1" > /etc/modprobe.d/kvm_intel.conf

For AMD processors:

sudo echo "options kvm_amd nested=1" > /etc/modprobe.d/kvm_amd.conf

Update the module settings:

sudo modprobe -r kvm_intel
sudo modprobe kvm_intel

(Replace kvm_intel with kvm_amd for AMD CPUs.)

Step 5: Verify Nested Virtualization

Check if nested virtualization is enabled:

cat /sys/module/kvm_intel/parameters/nested    # For Intel
cat /sys/module/kvm_amd/parameters/nested     # For AMD

If the output is Y, nested virtualization is enabled.

Step 6: Configure Guest VMs for Nested Virtualization

To use nested virtualization, create or modify your guest VM configuration. Using virt-manager:

1. Open the VM settings in virt-manager.
2. Navigate to Processor settings.
3. Enable Copy host CPU configuration.
4. Ensure that virtualization extensions are visible to the guest.

Alternatively, update the VM’s XML configuration:

sudo virsh edit <vm-name>

Add the following to the <cpu> section:

<cpu mode='host-passthrough'/>

Restart the VM for the changes to take effect.

Troubleshooting Tips

1. KVM Modules Fail to Load:

   • Ensure that virtualization is enabled in the BIOS/UEFI.
   • Verify hardware compatibility for nested virtualization.

2. Nested Feature Not Enabled:

   • Double-check /etc/modprobe.d/ configuration files for syntax errors.
   • Reload the kernel modules.

3. Performance Issues:

   • Nested virtualization incurs overhead; ensure sufficient CPU and memory resources for the host and guest VMs.

4. libvirt Errors:

   • Restart the libvirtd service:

     sudo systemctl restart libvirtd
     

Conclusion

Setting up nested KVM on AlmaLinux is an invaluable skill for IT professionals, developers, and educators who rely on virtualized environments for testing and development. By following this guide, you’ve configured your system for optimal performance with nested virtualization.

From enabling hardware support to tweaking VM settings, the process ensures a robust and flexible setup tailored to your needs. AlmaLinux’s stability and compatibility with enterprise-grade features like KVM make it an excellent choice for virtualization projects.

Now, you can confidently create multi-layered virtual environments to advance your goals in testing, development, or training.

9 - How to Make KVM Live Migration on AlmaLinux

Introduction

Live migration is a critical feature in virtualized environments, enabling seamless transfer of running virtual machines (VMs) between host servers with minimal downtime. This capability is essential for system maintenance, load balancing, and disaster recovery. AlmaLinux, a robust and community-driven enterprise-grade Linux distribution, offers an ideal platform for implementing KVM live migration.

This guide walks you through the process of configuring and performing KVM live migration on AlmaLinux. From setting up your environment to executing the migration, we’ll cover every step in detail to help you achieve smooth and efficient results.

What is KVM Live Migration?

KVM live migration involves transferring a running VM from one physical host to another without significant disruption to its operation. This feature is commonly used for:

• Hardware Maintenance: Moving VMs away from a host that requires updates or repairs.
• Load Balancing: Redistributing VMs across hosts to optimize resource usage.
• Disaster Recovery: Quickly migrating workloads during emergencies.

Live migration requires the source and destination hosts to share certain configurations, such as storage and networking, and demands proper setup for secure and efficient operation.

Prerequisites

To perform live migration on AlmaLinux, ensure the following prerequisites are met:

1. Hosts Configuration:

   • Two or more physical servers with similar hardware configurations.
   • AlmaLinux installed and configured on all participating hosts.

2. Shared Storage:

   • A shared storage system (e.g., NFS, GlusterFS, or iSCSI) accessible to all hosts.

3. Network:

   • Hosts connected via a high-speed network to minimize latency during migration.

4. Virtualization Tools:

   • KVM, libvirt, and related packages installed on all hosts.

5. Permissions:

   • Administrative privileges on all hosts.

6. Time Synchronization:

   • Synchronize the system clocks using tools like chronyd or ntpd.

Step-by-Step Guide to KVM Live Migration on AlmaLinux

Step 1: Install Required Packages

Ensure all required virtualization tools are installed on both source and destination hosts:

sudo dnf install qemu-kvm libvirt virt-manager -y

Start and enable the libvirt service:

sudo systemctl enable --now libvirtd

Verify that KVM is installed and functional:

virsh version

Step 2: Configure Shared Storage

Shared storage is essential for live migration, as both hosts need access to the same VM disk files.

• Setup NFS (Example):

  1. Install the NFS server on the storage host:

     sudo dnf install nfs-utils -y
     

  2. Configure the /etc/exports file to share the directory:

     /var/lib/libvirt/images *(rw,sync,no_root_squash)
     

  3. Start and enable the NFS service:

     sudo systemctl enable --now nfs-server
     

  4. Mount the shared storage on both source and destination hosts:

     sudo mount <storage-host-ip>:/var/lib/libvirt/images /var/lib/libvirt/images
     

Step 3: Configure Passwordless SSH Access

For secure communication, configure passwordless SSH access between the hosts:

ssh-keygen -t rsa
ssh-copy-id <destination-host-ip>

Test the connection to ensure it works without a password prompt:

ssh <destination-host-ip>

Step 4: Configure Libvirt for Migration

Edit the libvirtd.conf file on both hosts to allow migrations:

sudo nano /etc/libvirt/libvirtd.conf

Uncomment and set the following parameters:

listen_tls = 0
listen_tcp = 1
tcp_port = "16509"
auth_tcp = "none"

Restart the libvirt service:

sudo systemctl restart libvirtd

Step 5: Configure the Firewall

Open the necessary ports for migration on both hosts:

sudo firewall-cmd --add-port=16509/tcp --permanent
sudo firewall-cmd --add-port=49152-49216/tcp --permanent
sudo firewall-cmd --reload

Step 6: Perform Live Migration

Use the virsh command to perform the migration. First, list the running VMs on the source host:

virsh list

Execute the migration command:

virsh migrate --live <vm-name> qemu+tcp://<destination-host-ip>/system

Monitor the migration progress and verify that the VM is running on the destination host:

virsh list

Troubleshooting Tips

1. Migration Fails:

   • Verify network connectivity between the hosts.
   • Ensure both hosts have access to the shared storage.
   • Check for configuration mismatches in libvirtd.conf.

2. Firewall Issues:

   • Ensure the correct ports are open on both hosts using firewall-cmd --list-all.

3. Slow Migration:

   • Use a high-speed network for migration to reduce latency.
   • Optimize the VM’s memory allocation for faster data transfer.

4. Storage Access Errors:

   • Double-check the shared storage configuration and mount points.

Best Practices for KVM Live Migration

• Use Shared Storage: Ensure reliable shared storage for consistent access to VM disk files.
• Secure SSH Communication: Use SSH keys and restrict access to trusted hosts only.
• Monitor Resources: Keep an eye on CPU, memory, and network usage during migration to avoid resource exhaustion.
• Plan Maintenance Windows: Schedule live migrations during low-traffic periods to minimize potential disruption.

Conclusion

KVM live migration on AlmaLinux provides an efficient way to manage virtualized workloads with minimal downtime. Whether for hardware maintenance, load balancing, or disaster recovery, mastering live migration ensures greater flexibility and reliability in managing your IT environment.

By following the steps outlined in this guide, you’ve configured your AlmaLinux hosts to support live migration and performed your first migration successfully. With its enterprise-ready features and strong community support, AlmaLinux is an excellent choice for virtualization projects.

10 - How to Perform KVM Storage Migration on AlmaLinux

Introduction

Managing virtualized environments efficiently often requires moving virtual machine (VM) storage from one location to another. This process, known as storage migration, is invaluable for optimizing storage utilization, performing maintenance, or upgrading storage hardware. On AlmaLinux, an enterprise-grade Linux distribution, KVM (Kernel-based Virtual Machine) offers robust support for storage migration, ensuring minimal disruption to VMs during the process.

This detailed guide walks you through the process of performing KVM storage migration on AlmaLinux. From prerequisites to troubleshooting tips, we’ll cover everything you need to know to successfully migrate VM storage.

What is KVM Storage Migration?

KVM storage migration allows you to move the storage of a running or stopped virtual machine from one disk or storage pool to another. Common scenarios for storage migration include:

• Storage Maintenance: Replacing or upgrading storage systems without VM downtime.
• Load Balancing: Redistributing storage loads across multiple storage devices or pools.
• Disaster Recovery: Moving storage to a safer location or a remote backup.

KVM supports two primary types of storage migration:

1. Cold Migration: Migrating the storage of a stopped VM.
2. Live Storage Migration: Moving the storage of a running VM with minimal downtime.

Prerequisites

Before performing storage migration, ensure the following prerequisites are met:

1. Host System:

   • AlmaLinux 8 or newer installed.
   • KVM, QEMU, and libvirt configured and operational.

2. Storage:

   • Source and destination storage pools configured and accessible.
   • Sufficient disk space on the target storage pool.

3. Network:

   • For remote storage migration, ensure reliable network connectivity.

4. Permissions:

   • Administrative privileges to execute migration commands.

5. VM State:

   • The VM can be running or stopped, depending on the type of migration.

Step-by-Step Guide to KVM Storage Migration on AlmaLinux

Step 1: Verify KVM and Libvirt Setup

Ensure the necessary KVM and libvirt packages are installed:

sudo dnf install qemu-kvm libvirt virt-manager -y

Start and enable the libvirt service:

sudo systemctl enable --now libvirtd

Verify that KVM is functional:

virsh version

Step 2: Check VM and Storage Details

List the running VMs to confirm the target VM’s status:

virsh list --all

Check the VM’s current disk and storage pool details:

virsh domblklist <vm-name>

This command displays the source location of the VM’s storage disk(s).

Step 3: Add or Configure the Target Storage Pool

If the destination storage pool is not yet created, configure it using virsh or virt-manager.

• Creating a Storage Pool:

  1. Define the new storage pool:

     virsh pool-define-as <pool-name> dir --target <path-to-storage>
     

  2. Build and start the pool:

     virsh pool-build <pool-name>
     virsh pool-start <pool-name>
     

  3. Make it persistent:

     virsh pool-autostart <pool-name>
     

• Verify Storage Pools:

  virsh pool-list --all
  

Step 4: Perform Cold Storage Migration

If the VM is stopped, you can perform cold migration using the virsh command:

virsh dumpxml <vm-name> > <vm-name>.xml
virsh shutdown <vm-name>
virsh migrate-storage <vm-name> <destination-pool-name>

Once completed, start the VM to verify its functionality:

virsh start <vm-name>

Step 5: Perform Live Storage Migration

Live migration allows you to move the storage of a running VM with minimal downtime.

1. Command for Live Storage Migration:

   virsh blockcopy <vm-name> <disk-target> --dest <new-path> --format qcow2 --wait --verbose
   

   • <disk-target>: The name of the disk as shown in virsh domblklist.
   • <new-path>: The destination storage path.

2. Monitor Migration Progress:

   virsh blockjob <vm-name> <disk-target> --info
   

3. Commit Changes: After the migration completes, commit the changes:

   virsh blockcommit <vm-name> <disk-target>
   

Step 6: Verify the Migration

After the migration, verify the VM’s storage configuration:

virsh domblklist <vm-name>

Ensure the disk is now located in the destination storage pool.

Troubleshooting Tips

1. Insufficient Space:

   • Verify available disk space on the destination storage pool.
   • Use tools like df -h to check storage usage.

2. Slow Migration:

   • Optimize network bandwidth for remote migrations.
   • Consider compressing disk images to reduce transfer time.

3. Storage Pool Not Accessible:

   • Ensure the storage pool is mounted and started:

     virsh pool-start <pool-name>
     

   • Verify permissions for the storage directory.

4. Migration Fails Midway:

   • Restart the libvirtd service:

     sudo systemctl restart libvirtd
     

5. VM Boot Issues Post-Migration:

   • Verify that the disk path is updated in the VM’s XML configuration:

     virsh edit <vm-name>
     

Best Practices for KVM Storage Migration

• Plan Downtime for Cold Migration: Schedule migrations during off-peak hours to minimize impact.
• Use Fast Storage Systems: High-speed storage (e.g., SSDs) can significantly improve migration performance.
• Test Before Migration: Perform a test migration on a non-critical VM to ensure compatibility.
• Backup Data: Always backup VM storage before migration to prevent data loss.
• Monitor Resource Usage: Keep an eye on CPU, memory, and network usage during migration to prevent bottlenecks.

Conclusion

KVM storage migration on AlmaLinux is an essential skill for system administrators managing virtualized environments. Whether upgrading storage, balancing loads, or ensuring disaster recovery, the ability to migrate VM storage efficiently ensures a robust and adaptable infrastructure.

By following this step-by-step guide, you’ve learned how to perform both cold and live storage migrations using KVM on AlmaLinux. With careful planning, proper configuration, and adherence to best practices, you can seamlessly manage storage resources while minimizing disruptions to running VMs.

11 - How to Set Up UEFI Boot for KVM Virtual Machines on AlmaLinux

Introduction

Modern virtualized environments demand advanced booting features to match the capabilities of physical hardware. Unified Extensible Firmware Interface (UEFI) is the modern replacement for the traditional BIOS, providing faster boot times, better security, and support for large disks and advanced features. When setting up virtual machines (VMs) on AlmaLinux using KVM (Kernel-based Virtual Machine), enabling UEFI boot allows you to harness these benefits in your virtualized infrastructure.

This guide explains the steps to set up UEFI boot for KVM virtual machines on AlmaLinux. We’ll cover the prerequisites, detailed configuration, and troubleshooting tips to ensure a seamless setup.

What is UEFI Boot?

UEFI is a firmware interface that initializes hardware during boot and provides runtime services for operating systems and programs. It is more advanced than the traditional BIOS and supports:

• Faster Boot Times: Due to optimized hardware initialization.
• Secure Boot: Prevents unauthorized code from running during startup.
• Support for GPT: Enables booting from disks larger than 2 TB.
• Compatibility: Works with legacy systems while enabling modern features.

By setting up UEFI boot in KVM, you can create virtual machines with these advanced boot capabilities, making them more efficient and compatible with modern operating systems.

Prerequisites

Before setting up UEFI boot, ensure the following requirements are met:

1. Host System:

   • AlmaLinux 8 or newer installed.
   • KVM, QEMU, and libvirt configured and operational.

2. UEFI Firmware:

   • Install the edk2-ovmf package for UEFI support in KVM.

3. Permissions:

   • Administrative privileges to configure virtualization settings.

4. VM Compatibility:

   • An operating system ISO compatible with UEFI, such as Windows 10 or AlmaLinux.

Step-by-Step Guide to Set Up UEFI Boot for KVM VMs on AlmaLinux

Step 1: Install and Configure Required Packages

Ensure the necessary virtualization tools and UEFI firmware are installed:

sudo dnf install qemu-kvm libvirt virt-manager edk2-ovmf -y

• qemu-kvm: Provides the KVM hypervisor.
• libvirt: Manages virtual machines.
• virt-manager: Offers a GUI for managing VMs.
• edk2-ovmf: Provides UEFI firmware files for KVM.

Verify that KVM is working:

virsh version

Step 2: Create a New Storage Pool for UEFI Firmware (Optional)

The edk2-ovmf package provides UEFI firmware files stored in /usr/share/edk2/. To make them accessible to all VMs, you can create a dedicated storage pool.

1. Define the storage pool:

   virsh pool-define-as uefi-firmware dir --target /usr/share/edk2/
   

2. Build and start the pool:

   virsh pool-build uefi-firmware
   virsh pool-start uefi-firmware
   

3. Autostart the pool:

   virsh pool-autostart uefi-firmware
   

Step 3: Create a New Virtual Machine

Use virt-manager or virt-install to create a new VM.

• Using virt-manager:

  1. Open virt-manager and click Create a new virtual machine.
  2. Select the installation source (ISO file or PXE boot).
  3. Configure memory, CPU, and storage.

• Using virt-install:

  virt-install \
  --name my-uefi-vm \
  --memory 2048 \
  --vcpus 2 \
  --disk size=20 \
  --cdrom /path/to/os.iso \
  --os-variant detect=on
  

Do not finalize the VM configuration yet; proceed to the UEFI-specific settings.

Step 4: Enable UEFI Boot for the VM

1. Access the VM’s XML Configuration:

   virsh edit <vm-name>
   

2. Add UEFI Firmware: Locate the <os> section and add the UEFI loader:

   <os>
       <type arch='x86_64' machine='pc-q35-6.2'>hvm</type>
       <loader readonly='yes' type='pflash'>/usr/share/edk2/ovmf/OVMF_CODE.fd</loader>
       <nvram>/var/lib/libvirt/nvram/<vm-name>.fd</nvram>
   </os>
   

3. Specify the Machine Type: Modify the <type> element to use the q35 machine type, which supports UEFI.

4. Save and Exit: Save the file and close the editor. Restart the VM to apply changes.

Step 5: Install the Operating System

Boot the VM and proceed with the operating system installation:

1. During installation, ensure the disk is partitioned using GPT instead of MBR.
2. If the OS supports Secure Boot, you can enable it during the installation or post-installation configuration.

Step 6: Test UEFI Boot

Once the installation is complete, reboot the VM and verify that it boots using UEFI firmware:

• Access the UEFI shell during boot if needed by pressing ESC or F2.
• Check the boot logs in virt-manager or via virsh to confirm the UEFI loader is initialized.

Troubleshooting Tips

1. VM Fails to Boot:

   • Ensure the <loader> path is correct.
   • Verify that the UEFI firmware package (edk2-ovmf) is installed.

2. No UEFI Option in virt-manager:

   • Check if virt-manager is up-to-date:

     sudo dnf update virt-manager
     

   • Ensure the edk2-ovmf package is installed.

3. Secure Boot Issues:

   • Ensure the OS supports Secure Boot.
   • Disable Secure Boot in the UEFI settings if not needed.

4. Incorrect Disk Partitioning:

   • During OS installation, ensure you select GPT partitioning.

5. Invalid Machine Type:

   • Use the q35 machine type in the VM XML configuration.

Best Practices for UEFI Boot in KVM VMs

• Update Firmware: Regularly update the UEFI firmware files for better compatibility and security.
• Enable Secure Boot Carefully: Secure Boot can enhance security but may require additional configuration for non-standard operating systems.
• Test New Configurations: Test UEFI boot on non-production VMs before applying it to critical workloads.
• Document Configurations: Keep a record of changes made to the VM XML files for troubleshooting and replication.

Conclusion

Enabling UEFI boot for KVM virtual machines on AlmaLinux provides a modern and efficient boot environment that supports advanced features like Secure Boot and GPT partitioning. By following the steps outlined in this guide, you can configure UEFI boot for your VMs, enhancing their performance, compatibility, and security.

Whether you’re deploying new VMs or upgrading existing ones, UEFI is a worthwhile addition to your virtualized infrastructure. AlmaLinux, paired with KVM and libvirt, makes it straightforward to implement and manage UEFI boot in your environment.

12 - How to Enable TPM 2.0 on KVM on AlmaLinux

How to Enable TPM 2.0 on KVM on AlmaLinux

Introduction

Trusted Platform Module (TPM) 2.0 is a hardware-based security feature that enhances the security of systems by providing encryption keys, device authentication, and secure boot. Enabling TPM 2.0 in virtualized environments has become increasingly important for compliance with modern operating systems like Windows 11, which mandates TPM for installation.

In this guide, we will explore how to enable TPM 2.0 for virtual machines (VMs) running on KVM (Kernel-based Virtual Machine) in AlmaLinux. This detailed walkthrough covers the prerequisites, configuration steps, and troubleshooting tips for successfully integrating TPM 2.0 in your virtualized environment.

What is TPM 2.0?

TPM 2.0 is the second-generation Trusted Platform Module, providing enhanced security features compared to its predecessor. It supports:

• Cryptographic Operations: Handles secure key generation and storage.
• Platform Integrity: Ensures the integrity of the system during boot through secure measurements.
• Secure Boot: Protects against unauthorized firmware and operating system changes.
• Compliance: Required for running modern operating systems like Windows 11.

In a KVM environment, TPM can be emulated using the swtpm package, which provides software-based TPM features for virtual machines.

Prerequisites

Before enabling TPM 2.0, ensure the following requirements are met:

1. Host System:

   • AlmaLinux 8 or newer installed.
   • KVM, QEMU, and libvirt configured and operational.

2. TPM Support:

   • Install the swtpm package for software-based TPM emulation.

3. VM Compatibility:

   • A guest operating system that supports TPM 2.0, such as Windows 11 or Linux distributions with TPM support.

4. Permissions:

   • Administrative privileges to configure virtualization settings.

Step-by-Step Guide to Enable TPM 2.0 on KVM on AlmaLinux

Step 1: Install Required Packages

Ensure the necessary virtualization tools and TPM emulator are installed:

sudo dnf install qemu-kvm libvirt virt-manager swtpm -y

• qemu-kvm: Provides the KVM hypervisor.
• libvirt: Manages virtual machines.
• virt-manager: GUI for managing VMs.
• swtpm: Software TPM emulator.

Start and enable the libvirt service:

sudo systemctl enable --now libvirtd

Step 2: Verify TPM Support

Verify that swtpm is installed and working:

swtpm --version

Check for the TPM library files on your system:

ls /usr/share/swtpm

Step 3: Create a New Virtual Machine

Use virt-manager or virt-install to create a new virtual machine. This VM will later be configured to use TPM 2.0.

• Using virt-manager:

  1. Open virt-manager and click Create a new virtual machine.
  2. Select the installation source (ISO file or PXE boot).
  3. Configure memory, CPU, and storage.

• Using virt-install:

  virt-install \
  --name my-tpm-vm \
  --memory 4096 \
  --vcpus 4 \
  --disk size=40 \
  --cdrom /path/to/os.iso \
  --os-variant detect=on
  

Do not finalize the configuration yet; proceed to enable TPM.

Step 4: Enable TPM 2.0 for the VM

1. Edit the VM’s XML Configuration:

   virsh edit <vm-name>
   

2. Add TPM Device Configuration: Locate the <devices> section in the XML file and add the following TPM configuration:

   <tpm model='tpm-tis'>
       <backend type='emulator' version='2.0'>
           <options/>
       </backend>
   </tpm>
   

3. Set Emulator for Software TPM: Ensure that the TPM emulator points to the swtpm backend for proper functionality.

4. Save and Exit: Save the XML file and close the editor.

Step 5: Start the Virtual Machine

Start the VM and verify that TPM 2.0 is active:

virsh start <vm-name>

Inside the VM’s operating system, check for the presence of TPM:

• Windows: Open tpm.msc from the Run dialog to view the TPM status.

• Linux: Use the tpm2-tools package to query TPM functionality:

  sudo tpm2_getcap properties-fixed
  

Step 6: Secure the TPM Emulator

By default, the swtpm emulator does not persist data. To ensure TPM data persists across reboots:

1. Create a directory to store TPM data:

   sudo mkdir -p /var/lib/libvirt/swtpm/<vm-name>
   

2. Modify the XML configuration to use the new path:

   <tpm model='tpm-tis'>
       <backend type='emulator' version='2.0'>
           <path>/var/lib/libvirt/swtpm/<vm-name></path>
       </backend>
   </tpm>
   

Troubleshooting Tips

1. TPM Device Not Detected in VM:

   • Ensure the swtpm package is correctly installed.
   • Double-check the XML configuration for errors.

2. Unsupported TPM Version:

   • Verify that the version='2.0' attribute is correctly specified in the XML file.

3. Secure Boot Issues:

   • Ensure the operating system and VM are configured for UEFI and Secure Boot compatibility.

4. TPM Emulator Fails to Start:

   • Restart the libvirtd service:

     sudo systemctl restart libvirtd
     

   • Check the libvirt logs for error messages:

     sudo journalctl -u libvirtd
     

Best Practices for Using TPM 2.0 on KVM

• Backup TPM Data: Securely back up the TPM emulator directory for disaster recovery.
• Enable Secure Boot: Combine TPM with UEFI Secure Boot for enhanced system integrity.
• Monitor VM Security: Regularly review and update security policies for VMs using TPM.
• Document Configuration Changes: Keep detailed records of XML modifications for future reference.

Conclusion

Enabling TPM 2.0 for KVM virtual machines on AlmaLinux ensures compliance with modern operating system requirements and enhances the security of your virtualized environment. By leveraging the swtpm emulator and configuring libvirt, you can provide robust hardware-based security features for your VMs.

This guide has provided a comprehensive walkthrough to set up and manage TPM 2.0 in KVM. Whether you’re deploying secure applications or meeting compliance requirements, TPM is an essential component of any virtualized infrastructure.

13 - How to Enable GPU Passthrough on KVM with AlmaLinux

Introduction

GPU passthrough allows a physical GPU to be directly assigned to a virtual machine (VM) in a KVM (Kernel-based Virtual Machine) environment. This feature is crucial for high-performance tasks such as gaming, 3D rendering, video editing, and machine learning, as it enables the VM to utilize the full power of the GPU. AlmaLinux, a stable and robust enterprise-grade Linux distribution, provides a reliable platform for setting up GPU passthrough.

In this guide, we will explain how to configure GPU passthrough on KVM with AlmaLinux. By the end of this tutorial, you will have a VM capable of leveraging your GPU’s full potential.

What is GPU Passthrough?

GPU passthrough is a virtualization feature that dedicates a host machine’s physical GPU to a guest VM, enabling near-native performance. It is commonly used in scenarios where high-performance graphics or compute power is required, such as:

• Gaming on VMs: Running modern games in a virtualized environment.
• Machine Learning: Utilizing GPU acceleration for training and inference.
• 3D Rendering: Running graphics-intensive applications within a VM.

GPU passthrough requires hardware virtualization support (Intel VT-d or AMD IOMMU), a compatible GPU, and proper configuration of the host system.

Prerequisites

Before starting, ensure the following requirements are met:

1. Hardware Support:

   • A CPU with hardware virtualization support (Intel VT-x/VT-d or AMD-V/IOMMU).
   • A GPU that supports passthrough (NVIDIA or AMD).

2. Host System:

   • AlmaLinux 8 or newer installed.
   • KVM, QEMU, and libvirt configured and operational.

3. Permissions:

   • Administrative privileges to configure virtualization and hardware.

4. BIOS/UEFI Configuration:

   • Enable virtualization extensions (Intel VT-d or AMD IOMMU) in BIOS/UEFI.

5. Additional Tools:

   • virt-manager for GUI management of VMs.
   • pciutils for identifying hardware devices.

Step-by-Step Guide to Configure GPU Passthrough on KVM with AlmaLinux

Step 1: Enable IOMMU in BIOS/UEFI

1. Restart your system and access the BIOS/UEFI settings.
2. Locate the virtualization options and enable Intel VT-d or AMD IOMMU.
3. Save the changes and reboot into AlmaLinux.

Step 2: Enable IOMMU on AlmaLinux

1. Edit the GRUB configuration file:

   sudo nano /etc/default/grub
   

2. Add the following parameters to the GRUB_CMDLINE_LINUX line:

   • For Intel:

     intel_iommu=on iommu=pt
     

   • For AMD:

     amd_iommu=on iommu=pt
     

3. Update GRUB and reboot:

   sudo grub2-mkconfig -o /boot/grub2/grub.cfg
   sudo reboot
   

Step 3: Verify IOMMU is Enabled

After rebooting, verify that IOMMU is enabled:

dmesg | grep -e DMAR -e IOMMU

You should see lines indicating that IOMMU is enabled.

Step 4: Identify the GPU and Bind it to the VFIO Driver

1. List all PCI devices and identify your GPU:

   lspci -nn
   

   Look for entries related to your GPU (e.g., NVIDIA or AMD).

2. Note the GPU’s PCI ID (e.g., 0000:01:00.0 for the GPU and 0000:01:00.1 for the audio device).

3. Bind the GPU to the VFIO driver:

   • Create a configuration file:

     sudo nano /etc/modprobe.d/vfio.conf
     

   • Add the following line, replacing <PCI-ID> with your GPU’s ID:

     options vfio-pci ids=<GPU-ID>,<Audio-ID>
     

4. Update the initramfs and reboot:

   sudo dracut -f --kver $(uname -r)
   sudo reboot
   

Step 5: Verify GPU Binding

After rebooting, verify that the GPU is bound to the VFIO driver:

lspci -nnk -d <GPU-ID>

The output should show vfio-pci as the driver in use.

Step 6: Create a Virtual Machine with GPU Passthrough

1. Open virt-manager and create a new VM or edit an existing one.

2. Configure the VM settings:

   • CPU: Set the CPU mode to “host-passthrough” for better performance.
   • GPU:
     1. Go to the Add Hardware section.
     2. Select PCI Host Device and add your GPU and its associated audio device.
   • Display: Disable SPICE or VNC and set the display to None.

3. Install the operating system on the VM (e.g., Windows 10 or Linux).

Step 7: Install GPU Drivers in the VM

1. Boot into the guest operating system.
2. Install the appropriate GPU drivers (NVIDIA or AMD).
3. Reboot the VM to apply the changes.

Step 8: Test GPU Passthrough

Run a graphics-intensive application or benchmark tool in the VM to confirm that GPU passthrough is working as expected.

Troubleshooting Tips

1. GPU Not Detected in VM:

   • Verify that the GPU is correctly bound to the VFIO driver.
   • Check the VM’s XML configuration to ensure the GPU is assigned.

2. IOMMU Errors:

   • Ensure that virtualization extensions are enabled in the BIOS/UEFI.
   • Verify that IOMMU is enabled in the GRUB configuration.

3. Host System Crashes or Freezes:

   • Check for hardware compatibility issues.
   • Ensure that the GPU is not being used by the host (e.g., use an integrated GPU for the host).

4. Performance Issues:

   • Use a dedicated GPU for the VM and an integrated GPU for the host.
   • Ensure that the CPU is in “host-passthrough” mode for optimal performance.

Best Practices for GPU Passthrough on KVM

• Use Compatible Hardware: Verify that your GPU supports virtualization and is not restricted by the manufacturer (e.g., some NVIDIA consumer GPUs have limitations for passthrough).
• Backup Configurations: Keep a backup of your VM’s XML configuration and GRUB settings for easy recovery.
• Allocate Sufficient Resources: Ensure the VM has enough CPU cores, memory, and disk space for optimal performance.
• Update Drivers: Regularly update GPU drivers in the guest OS for compatibility and performance improvements.

Conclusion

GPU passthrough on KVM with AlmaLinux unlocks the full potential of your hardware, enabling high-performance applications in a virtualized environment. By following the steps outlined in this guide, you can configure GPU passthrough for your VMs, providing near-native performance for tasks like gaming, rendering, and machine learning.

Whether you’re setting up a powerful gaming VM or a high-performance computing environment, AlmaLinux and KVM offer a reliable platform for GPU passthrough. With proper configuration and hardware, you can achieve excellent results tailored to your needs.

14 - How to Use VirtualBMC on KVM with AlmaLinux

Introduction

As virtualization continues to grow in popularity, tools that enhance the management and functionality of virtualized environments are becoming essential. VirtualBMC (Virtual Baseboard Management Controller) is one such tool. It simulates the functionality of a physical BMC, enabling administrators to manage virtual machines (VMs) as though they were physical servers through protocols like Intelligent Platform Management Interface (IPMI).

In this blog post, we’ll explore how to set up and use VirtualBMC (vBMC) on KVM with AlmaLinux. From installation to configuration and practical use cases, we’ll cover everything you need to know to integrate vBMC into your virtualized infrastructure.

What is VirtualBMC?

VirtualBMC is an OpenStack project that provides a software-based implementation of a Baseboard Management Controller. BMCs are typically used in physical servers for out-of-band management tasks like power cycling, monitoring hardware health, or accessing consoles. With VirtualBMC, similar capabilities can be extended to KVM-based virtual machines, enabling:

• Remote Management: Control and manage VMs remotely using IPMI.
• Integration with Automation Tools: Streamline workflows with tools like Ansible or OpenStack Ironic.
• Enhanced Testing Environments: Simulate physical server environments in a virtualized setup.

Prerequisites

Before diving into the setup process, ensure the following prerequisites are met:

1. Host System:

   • AlmaLinux 8 or newer installed.
   • KVM, QEMU, and libvirt configured and operational.

2. Network:

   • Network configuration that supports communication between the vBMC and the client tools.

3. Virtualization Tools:

   • virt-manager or virsh for managing VMs.
   • VirtualBMC package for implementing BMC functionality.

4. Permissions:

   • Administrative privileges to install packages and configure the environment.

Step-by-Step Guide to Using VirtualBMC on KVM

Step 1: Install VirtualBMC

1. Install VirtualBMC using pip:

   sudo dnf install python3-pip -y
   sudo pip3 install virtualbmc
   

2. Verify the installation:

   vbmc --version
   

Step 2: Configure VirtualBMC

1. Create a Configuration Directory: VirtualBMC stores its configuration files in /etc/virtualbmc or the user’s home directory by default. Ensure the directory exists:

   mkdir -p ~/.vbmc
   

2. Set Up Libvirt: Ensure libvirt is installed and running:

   sudo dnf install libvirt libvirt-python -y
   sudo systemctl enable --now libvirtd
   

3. Check Available VMs: List the VMs on your host to identify the one you want to manage:

   virsh list --all
   

4. Add a VM to VirtualBMC: Use the vbmc command to associate a VM with a virtual BMC:

   vbmc add <vm-name> --port <port-number>
   

   • Replace <vm-name> with the name of the VM (as listed by virsh).
   • Replace <port-number> with an unused port (e.g., 6230).

   Example:

   vbmc add my-vm --port 6230
   

5. Start the VirtualBMC Service: Start the vBMC instance for the configured VM:

   vbmc start <vm-name>
   

6. Verify the vBMC Instance: List all vBMC instances to ensure your configuration is active:

   vbmc list
   

Step 3: Use IPMI to Manage the VM

Once the VirtualBMC instance is running, you can use IPMI tools to manage the VM.

1. Install IPMI Tools:

   sudo dnf install ipmitool -y
   

2. Check Power Status: Use the IPMI command to query the power status of the VM:

   ipmitool -I lanplus -H <host-ip> -p <port-number> -U admin -P password power status
   

3. Power On the VM:

   ipmitool -I lanplus -H <host-ip> -p <port-number> -U admin -P password power on
   

4. Power Off the VM:

   ipmitool -I lanplus -H <host-ip> -p <port-number> -U admin -P password power off
   

5. Reset the VM:

   ipmitool -I lanplus -H <host-ip> -p <port-number> -U admin -P password power reset
   

Step 4: Automate vBMC Management with Systemd

To ensure vBMC starts automatically on boot, you can configure it as a systemd service.

1. Create a Systemd Service File: Create a service file for vBMC:

   sudo nano /etc/systemd/system/vbmc.service
   

2. Add the Following Content:

   [Unit]
   Description=Virtual BMC Service
   After=network.target
   
   [Service]
   Type=simple
   User=root
   ExecStart=/usr/local/bin/vbmcd
   
   [Install]
   WantedBy=multi-user.target
   

3. Enable and Start the Service:

   sudo systemctl enable vbmc.service
   sudo systemctl start vbmc.service
   

Step 5: Monitor and Manage vBMC

VirtualBMC includes several commands for monitoring and managing instances:

• List All vBMC Instances:

  vbmc list
  

• Show Details of a Specific Instance:

  vbmc show <vm-name>
  

• Stop a vBMC Instance:

  vbmc stop <vm-name>
  

• Remove a vBMC Instance:

  vbmc delete <vm-name>
  

Use Cases for VirtualBMC

1. Testing and Development: Simulate physical server environments for testing automation tools like OpenStack Ironic.

2. Remote Management: Control VMs in a way that mimics managing physical servers.

3. Learning and Experimentation: Practice IPMI-based management workflows in a virtualized environment.

4. Integration with Automation Tools: Use tools like Ansible to automate VM management via IPMI commands.

Troubleshooting Tips

1. vBMC Fails to Start:

   • Ensure that the libvirt service is running:

     sudo systemctl restart libvirtd
     

2. IPMI Commands Time Out:

   • Verify that the port specified in vbmc add is not blocked by the firewall:

     sudo firewall-cmd --add-port=<port-number>/tcp --permanent
     sudo firewall-cmd --reload
     

3. VM Not Found by vBMC:

   • Double-check the VM name using virsh list --all.

4. Authentication Issues:

   • Ensure you’re using the correct username and password (admin/password by default).

Best Practices for Using VirtualBMC

• Secure IPMI Access: Restrict access to the vBMC ports using firewalls or network policies.

• Monitor Logs: Check the vBMC logs for troubleshooting:

  journalctl -u vbmc.service
  

• Keep Software Updated: Regularly update VirtualBMC and related tools to ensure compatibility and security.

• Automate Tasks: Leverage automation tools like Ansible to streamline vBMC management.

Conclusion

VirtualBMC on KVM with AlmaLinux provides a powerful way to manage virtual machines as if they were physical servers. Whether you’re testing automation workflows, managing VMs remotely, or simulating a hardware environment, VirtualBMC offers a versatile and easy-to-use solution.

By following this guide, you’ve set up VirtualBMC, associated it with your VMs, and learned how to manage them using IPMI commands. This setup enhances the functionality and flexibility of your virtualized infrastructure, making it suitable for both production and development environments.