What’s New in Ubuntu 25.04 Plucky Puffin
kernel 6.14, confidential computing, arm64 support
Ubuntu 25.04, codenamed "Plucky Puffin," was released on April 17, 2025. This interim release focuses heavily on infrastructure modernization, enhanced security, and improved developer tooling that makes it particularly relevant for cloud-native environments.
Core Infrastructure Improvements
Linux 6.14 Kernel with Advanced Features Ubuntu Server 25.04 ships with the Linux 6.14 kernel, introducing several server-focused enhancements. The standout feature is the new sched_ext scheduling system, which provides a mechanism to implement scheduling policies as eBPF programs. This enables administrators to defer scheduling decisions to user-space programs and implement fully functional hot-swappable Linux schedulers using any language or tool accessible in user-space.
Enhanced Boot and System Management The release introduces Dracut as an experimental alternative to initramfs-tools, preparing for its full integration in Ubuntu 25.10. This change aims to improve boot performance and provide more reliable system initialization, particularly beneficial for server environments where boot time and reliability are critical.
Networking and Connectivity Enhancements
Advanced Network Management NetworkManager now includes support for wpa-psk-sha256 secured WiFi networks and allows routing-policy configuration on the backend. More importantly for server environments, Ubuntu 25.04 is the first release to use Netplan and systemd-networkd's wait-online feature to check for DNS resolution, providing a more reliable way to wait for a system to be considered online before starting services.
Secure Time Synchronization The availability of NTS-enabled time servers allows Ubuntu 25.04 to use securely provided network time by default, enhancing security and accuracy of time synchronization across server infrastructure.
Identity Management and Security
Enhanced Authentication Services Canonical has significantly improved identity and access management features through enhancements to Authd, Ubuntu's authentication service for cloud identity providers. The service now supports Google IAM in addition to Microsoft Entra ID, making it easier to integrate Ubuntu servers into modern cloud identity infrastructures.
Active Directory Integration ADSys, the Active Directory Group Policy client for Ubuntu, now supports the latest Polkit and includes numerous improvements and bug fixes to certificate enrollment, making enterprise Windows-Linux hybrid environments more manageable.
Confidential Computing Ubuntu Server 25.04 expands confidential computing capabilities with AMD SEV-SNP host support, making it an ideal platform for deploying AI workloads securely at scale in both public clouds and private data centers. This is particularly relevant for organizations dealing with sensitive data or compliance requirements.
Developer Tools and Programming Languages
Modern Development Stack The release includes updated toolchains for multiple programming languages essential for modern development:
Python 3.13 (default version)
Latest versions of Golang, Rust, .NET, LLVM 20, OpenJDK, and GCC
Early access to OpenJDK 24ea, OpenJDK 25ea, and GCC 15
Enhanced .NET plugin support in Snapcraft
DevPacks Introduction A notable innovation is the introduction of "devpacks" - snap bundles that provide the latest versions of development tools like formatters and linters. The first devpack is "devpack-for-spring," bringing the latest Spring Framework and Spring Boot projects to Ubuntu, significantly simplifying Java application development on server infrastructure.
Container and Virtualization Improvements
Enhanced Container Tooling Ubuntu Server 25.04 includes better container tooling via decoupled bpftools and linux-perf, improving the experience for containerized workloads and Kubernetes deployments. The kernel improvements also enhance Wine/Proton gaming support through the new NTSYNC driver, which can provide significant performance improvements for Windows compatibility layers.
ARM64 Server Support The release introduces official ARM64 server support, expanding deployment options for modern ARM-based server hardware and cloud instances. This is particularly relevant as cloud providers increasingly offer ARM-based instances for cost-effective computing.
Installation and Management
Subiquity Installer Improvements Ubuntu Server 25.04 features the next-generation Subiquity server installer, bringing the comfortable live session experience to server deployments. The installer provides a more intuitive interface while maintaining the automation capabilities essential for large-scale deployments.
APT 3.0 Package Management The release includes APT 3.0 with a revamped command-line interface, providing better package management capabilities and improved dependency resolution for server environments.
Performance and Optimization
System-Wide Optimizations Ubuntu Server 25.04 is built with -O3 optimization level for AMD64 systems, providing performance improvements across the board. Combined with kernel optimizations and improved scheduling, servers should see measurable performance gains in CPU-intensive workloads.
Memory and Resource Management The updated systemd 257 brings improved resource management capabilities, better handling of services, and enhanced logging features that are particularly beneficial in server environments.
Enterprise and Cloud Features
Cloud Integration Enhanced cloud authentication support includes integration with Microsoft Entra ID and Google identity services, making it easier to deploy Ubuntu servers in hybrid and multi-cloud environments with centralized identity management.
Automation and Orchestration The release maintains full compatibility with automation tools like Ansible, Terraform, and cloud-init, while improving the underlying systems to make infrastructure-as-code deployments more reliable and predictable.