Introduction

These release notes for Ubuntu 21.04 (Hirsute Hippo) provide an overview of the release and document the known issues with Ubuntu and its flavours.

Dedication

Subscribers to the ubuntu-announce mailing list and long term participants in the Ubuntu community will have come across Adam Conrad’s work. Adam, known in the community as infinity, was a long-term member of the release team and colleague to many of us at Canonical. As a member of the release team, Adam was responsible for devising many of the processes and tools which we use today, and (whether he wanted to or not) teaching his fellow members the ropes. Adam passed away earlier this year after being unwell for some time. The Ubuntu Release Team dedicates 21.04 “Hirsute Hippo” to our colleague and friend infinity. He is missed and will live in our hearts forever.

Support lifespan

Ubuntu 21.04 will be supported for 9 months until January 2022. If you need Long Term Support, it is recommended you use Ubuntu 20.04 LTS instead.

Get Ubuntu 21.04

Download Ubuntu 21.04

Images can be downloaded from a location near you.

You can download ISOs and flashable images from:

• Ubuntu Desktop and Server for 64-bit x86 (AMD64)
• Less Frequently Downloaded Ubuntu Images
• Ubuntu Cloud Images
• Lubuntu
• Kubuntu
• Ubuntu Budgie
• Ubuntu Kylin
• Ubuntu MATE
• Ubuntu Studio
• Xubuntu

New features in 21.04

Updated Packages

Linux kernel 

Ubuntu 21.04 includes the 5.11 Linux kernel. This includes numerous updates and added support since the 5.8 Linux kernel released in Ubuntu 20.10. Some notable examples include:

• Better anonymous memory management to reduce swapping
• New cgroup slab controller which allows sharing of slab memory between cgroups
• Proactive memory compaction to reduce latency for huge-page allocations under fragmented memory conditions
• Support for running BPF programs on socket lookups
• FSGSBASE support to improve context switch performance on x86 processors
• Support for using Intel SGX to create encrypted enclaves
• Support for running SEV-ES guests under KVM to protect guest register state from the hypervisor
• Support for extended attributes in NFS
• fsync() performance improvements for ext4 and btrfs
• Btrfs performance and data recovery improvements
• io_uring restriction support to facilitate secure sharing of rings to less-trusted processes
• virtio-fs DAX support to improve performance and reduce memory consumption
• Intel Rocketlake and DG1 graphics support
• AMD Vangogh, Green Sardine, and Dimgrey Cavefish graphics support

Toolchain Upgrades 

GCC was updated to the 10.3.0 release, binutils to 2.36.1, and glibc to 2.33. Python now ships at version 3.9.4, Perl at version 5.32.1. LLVM now defaults to version 12. golang defaults to version 1.16.x. rustc defaults to version 1.50.

In addition to OpenJDK 11, OpenJDK 16 is now provided (but not used for package builds).

Ruby was updated from v2.7.0 to v2.7.2, and rubygems has been extracted from ruby2.7 source and is provided as a separate package.

Security Improvements 

Secureboot on x86_64 (amd64) and AArch64 (arm64) have been improved to include SBAT capable shim, grub2, fwupd. For more details see this discourse post.

nftables is now the default backend for the firewall.

Ubuntu Desktop

• Added support for smartcard authentication (via pam_sss)
• Wayland is now the default on most configurations, which features better security and performance
• The desktop view now properly handles drag and drop interactions, e.g. dragging from/to the file manager
• The power profile mode can now be changed from the settings (on configuration where there is proper kernel support)
• Pipewire support is now enabled which restore working screen recording and allow better audio handling for sandboxed applications
• The installer includes support for specifying a recovery key, which can be used to decrypt the disk if the password is forgotten
• The Active Directory integration has been improved. User authentication with GPO enabled works out of the box after installation. It also includes a Group Policy client (ADSys) to configure various settings from a central AD controller.

GNOME 

While the new shell version hasn’t been included yet in Ubuntu the applications have been mostly updated to their GNOME 40 versions.

Updated Applications

• Firefox version 87
• LibreOffice version 7.1.2-rc2
• Thunderbird version 78.8.1

Updated Subsystems

• PulseAudio 14
• BlueZ 5.56
• NetworkManager 1.30