Complete Guide to Incus 7.4: How to Utilize the New Features

Incus 7.4 is the latest version of the container and virtual machine manager system, which introduces several advanced features for managing containers and virtual machines. This guide explains how to use the new near-live container migration feature, one of the main novelties of this release.

Near-live container migration is useful for moving containers between systems or nodes of a cluster with minimal downtime. This feature is particularly advantageous for system administrators who require high availability and service continuity.

The guide is aimed at technical users who are familiar with Incus and with containerization and virtualization concepts. A basic knowledge of command-line commands and system administration operations is assumed.

By the end of this guide, you will be able to perform near-live container migrations using Incus 7.4, leveraging the new command options and advanced container management features.

Prerequisites

• Hardware: System compatible with Incus 7.4, with support for ZFS or Btrfs for near-live container migration.
• Software: Incus 7.4 installed on the system.
• Administrative access: Administrator privileges to run Incus commands.
• Network environment: Adequate network configuration for communication between cluster nodes or remote servers.

PROCEDURE: Near-real-time container migration with Incus 7.4

• Make sure you have Incus 7.4 installed on both systems, source and destination.
• Verify that the containers to be migrated are stored on ZFS or Btrfs.

Step 1: Container Preparation

Run the following command to ensure the container is running:

• incus start

Step 2: Performing the Migration

Use the incus move command with the --refresh option to start the near-real-time migration:

• incus move --refresh

Step 3: Verifying the Migration

After the migration, verify that the container is running on the destination system:

• incus list --location

Step 4: Migration during cluster evacuation (optional)

If you are evacuating a cluster, you can use the refresh-migrate option with the cluster.evacuate command:

• cluster.evacuate --refresh-migrate

Verification and Troubleshooting

After configuring and using the new features of Incus 7.4, it is important to verify proper functioning and know how to intervene in case of problems.

Testing near-live container migration

Testing UEFI Secure Boot management

• Step 1: Use the command incus secureboot to manage entries in the Secure Boot databases of virtual machines.
• Step 2: Verify that the changes made are reflected in the Secure Boot databases.

Testing UEFI boot override

• Step 1: Use the command incus start --override-boot to choose a specific UEFI boot entry.
• Step 2: Verify that the virtual machine boots with the selected boot entry.

Testing new networking features

• Step 1: Configure the restricted.networks.access key to allow restricted projects to access selected networks from the default project.
• Step 2: Verify that restricted projects can access the configured networks.

Testing new storage features

• Step 1: Configure the ceph.rbd.backend option to use the Ceph userspace library.
• Step 2: Verify that Incus correctly accesses RBD volumes through the Ceph userspace library.

Troubleshooting

If the near-live container migration fails, make sure that:

• The destination system is reachable and correctly configured.
• There are no network problems between the systems involved.

If UEFI Secure Boot management does not work as expected, verify that:

• The entries in the Secure Boot databases are correctly configured.
• The virtual machine supports UEFI Secure Boot.

For more details and support, consult the release announcement or the complete changelog.

Educational Summary and Practical Invitation

At the end of this guide, you will have a complete overview of the new features introduced in Incus 7.4 and you will know how to leverage its advanced features for managing containers and virtual machines.

• Near-live container migration: You will learn how to use the --refresh option to perform more reliable migrations compared to the traditional CRIU-based method.
• UEFI Secure Boot management: You will discover how to administer Secure Boot databases directly through the new low-level commands.
• Advanced network configurations: You will learn how to configure selected access to networks of the default project and manage DNS NOTIFY messages.
• Traffic and storage control: You will learn how to set burst limits for disks and network interfaces, improving performance flexibility.
• Disaster recovery and security: You will learn about improvements in shared storage recovery and fixes for critical vulnerabilities.

To experience these new features firsthand, visit the Incus online platform and start exploring the potential of version 7.4.