By Leann Ogasawara, Director of Kernel Engineering
Ubuntu has long been a popular choice for Linux instances on Azure. Our ongoing partnership with Microsoft has brought forth great results, such as the support of the latest Azure features, Ubuntu underlying SQL Server instances, bash on Windows, Ubuntu containers with Hyper-V Isolation on Windows 10 and Windows Servers, and much more.
Canonical, with the team at Microsoft Azure, are now delighted to announce that as of September 21, 2017, Ubuntu Cloud Images for Ubuntu 16.04 LTS on Azure have been enabled with a new Azure tailored Ubuntu kernel by default. The Azure tailored Ubuntu kernel will receive the same level of support and security maintenance as all supported Ubuntu kernels for the duration of the Ubuntu 16.04 LTS support life.
The kernel itself is provided by the linux-azure kernel package. The most notable highlights for this kernel include:
- Infiniband and RDMAcapability for Azure HPC to deliver optimized performance of compute intensive workloads on Azure A8, A9, H-series, and NC24r.
- Full support for Accelerated Networking in Azure. Direct access to the PCI device provides gains in overall network performance offering the highest throughput and lowest latency for guests in Azure. Transparent SR-IOV eliminates configuration steps for bonding network devices. SR-IOV for Linux in Azure is in preview but will become generally available later this year.
- NAPI and Receive Segment Coalescing for 10% greater throughput on guests not using SR-IOV.
- 18% reduction in kernel size.
- Hyper-V socket capability — a socket-based host/guest communication method that does not require a network.
- The very latest Hyper-V device drivers and feature support available.
The ongoing collaboration between Canonical and Microsoft will also continue to produce upgrades to newer kernel versions providing access to the latest kernel features, bug fixes, and security updates. Any Ubuntu 16.04 LTS image brought up from the Azure portal after September 21st will be running on this Azure tailored Ubuntu kernel.
How to verify which kernel is used:
$ uname -r
Instances using the Azure tailored Ubuntu kernel will, of course, be supportable through Canonical’s Ubuntu Advantage service, available for purchase on our online shop or through firstname.lastname@example.org in three tiers:
- Essential: designed for self-sufficient users, providing access to our self-support portal as well as a variety of Canonical tools and services.
- Standard: adding business-hours web and email support on top of the contents of Essential, as well as a 2-hour to 2-business days response time (severity 1-4).
- Advanced: adding 24×7 web and email support on top of the contents of Essential, as well as a 1-hour to 1-business day response time (severity 1-4).
The Azure tailored Ubuntu kernel will not support the Canonical Livepatch Service at the time of this announcement, but investigation is underway to evaluate delivery of this service in the future.
If, for now, you prefer livepatching at scale over the above performance improvements, it is possible to revert to the standard kernel, using the following commands:
$ sudo apt install linux-virtual linux-cloud-tools-virtual
$ sudo apt purge linux*azure
$ sudo reboot
As we continue to collaborate closely with various Microsoft teams on public cloud, private cloud, containers and services, you can expect further boosts in performance, simplification of operations at scale, and enablement of new innovations and technologies.