Microsoft has announced some changes to the release schedule and servicing model for Windows Server. The new Semi-Annual Channel is a twice-per-year feature update release with an 18 month servicing timeline (meaning that Mainstream support ends 18 months after that Semi-Annual Channel release becomes available).
The current release in this channel is Windows Server, version 1709, which became available on October 17, 2017. This release will fall out of Mainstream support on April 18, 2019, and there is no Extended support period. In this new model, Windows Server releases are identified by the year and month of release: for example, in 2017, a release in the 9th month (September) would be identified as version 1709.
Microsoft describes the Semi-Annual Channel below:
“The Semi-Annual Channel provides opportunity for customers who are innovating quickly to take advantage of new operating system capabilities at a faster pace, both in applications – particularly those built on containers and microservices – and in the software-defined hybrid datacenter.”
You also have the option of staying on the Windows Server 2016 Long-Term Servicing Channel (LTSC) with the traditional five years of Mainstream support, five years of Extended support, and the option to purchase Premium Assurance, for six more years of support. The current release in this channel is Windows Server 2016, version 2016 which became available on October 12, 2016. This release will fall out of Mainstream support on January 11, 2022, and it will fall out of Extended support on January 11, 2027. The LTSC is scheduled to have new releases every two to three years.
The Semi-Annual Channel will be available to volume-licensed customers with Software Assurance, as well as via the Azure Marketplace or other cloud/hosting service providers and loyalty programs such as Visual Studio Subscriptions.
The Semi-Annual Channel can be installed as a Nano Server or Server Core, but is not available as Server with Desktop Experience. The Long-Term Servicing Channel can be installed as a Server with Desktop Experience or Server Core, but is not available as Nano Server.
Implications for SQL Server Usage
If you want to use the Semi-Annual Channel, you will have to be comfortable running SQL Server on Server Core (with no integrated GUI). You can either start using Powershell or you can use tools like Project Honolulu, which is a locally deployed, browser-based, management tool set that enables on-premises administration of Windows Servers with no Azure or cloud dependency.
The two most interesting new features for SQL Server in Windows Server, version 1709 are Storage-Class memory support for Hyper-V VMs and Virtualized Persistent Memory (vPMEM) for Hyper-V VMs.
Storage-class memory support for VMs enables NTFS-formatted direct access volumes to be created on non-volatile DIMMs and exposed to Hyper-V VMs. This enables Hyper-V VMs to leverage the low-latency performance benefits of storage-class memory devices. Virtualized Persistent Memory (vPMEM) is enabled by creating a VHD file (.vhdpmem) on a direct access volume on a host, adding a vPMEM Controller to a VM, and adding the created device (.vhdpmem) to a VM. Using vhdpmem files on direct access volumes on a host to back vPMEM enables allocation flexibility and leverages a familiar management model for adding disks to VMs.+
Virtualized Persistent Memory (vPMEM) is enabled by creating a VHD file (.vhdpmem) on a direct access volume on a host, adding a vPMEM Controller to a VM, and adding the created device (.vhdpmem) to a VM. Using vhdpmem files on direct access volumes on a host to back vPMEM enables allocation flexibility and leverages a familiar management model for adding disks to VMs.
Using Storage-class memory in a VM will let you use the Persisted Log Buffer feature (aka “tail of the log caching”) that was introduced in SQL Server 2016 SP1, as described here.