There are many decisions that need to be made when it comes to managing and maintaining a Windows Server environment. With the newest versions of Windows Server, there are other decisions that need to be made that were not relevant in legacy versions of Windows Server that determine the licensing, support and release cadence that is followed in the environment.
Windows Server SAC and LTSC Differences and Use Cases
Unlike the old days of Windows Server, Microsoft has introduced two ways of running Windows Server that can help support different use cases when it comes to Windows Server as we will see.
The two release cadences with Windows Server now include:
- Semi-Annual Channel (SAC) release
- Long-Term Servicing Channel (LTSC) release
Each of these two releases includes various strengths and use cases that need to be considered before choosing one or the other to run production workloads in your environment.
The release cadence affects the licensing and support and other factors of the Windows Server environment that businesses must take into account when making the decision which release to choose for a certain use case.
Let’s take a look at Windows Server SAC and LTSC Differences and Use Cases to help make the decision between these two different release cycles of Windows Server.
Semi-Annual Channel (SAC) Release
The first release cadence we want to look at is the Semi-Annual Channel (SAC) version. This is the new release cadence that is different from the traditional cadence that most are used to with Windows Server.
With the Semi-Annual Channel (SAC) release, Microsoft produces a new SAC twice a year. The timing of each new SAC is generally in the spring and fall of each year. It is also important to note; the Semi-Annual Channel (SAC) versions of Windows are the Windows Server releases that are followed by a “number” such as Windows Server 1903 (most recently released). Technically, even though we might think of this latest version as a variant of Windows Server 2019, it really isn’t Windows Server 2019, but rather Windows Server 1903 as mentioned.
Support for Semi-Annual Channel (SAC)
Using the Semi-Annual Channel (SAC) versions of Windows Server also means very short support cadences to go along with the release itself. Support for the SAC versions of Windows Server only lasts for 18 months. This is an extremely short interval when compared to the traditional Windows Server support lifecycle that most are accustomed to in the enterprise environment.
For most businesses, provisioning new Windows Servers to replace the end of life SAC versions twice a year or at least within an 18-month period of supportability from Microsoft, is not desirable.
Semi-Annual Channel (SAC) Use Case
What are the Semi-Annual Channel (SAC) versions of Windows best suited for? – Immutable Infrastructure.
With immutable infrastructure, which is a new way of thinking about provisioning infrastructure in this age of DevOps, Windows Servers are never upgraded, but rather are “replaced” if a new feature or software upgrade is needed. Immutable infrastructure is generally associated with technology such as containers. Containers generally have a very short lifespan when compared to VMs, etc. So, organizations that run the Semi-Annual Channel (SAC) releases are not going to run into as many issues replacing a container host with a new SAC release. This type of upgrade cadence is generally not as well-suited for more traditional, monolithic applications found in many SMB environments.
Another important reason that businesses may choose SAC over LTSC releases is new features. The Semi-Annual Channel (SAC) versions of Windows, with their much quicker release cycle, also get new Windows features and enhancements much quicker than the Long-Term Servicing Channel (LTSC) versions. If businesses want to stay on the “bleeding edge” of the latest technology from Microsoft, the Semi-Annual Channel (SAC) versions of Windows are the version that will allow businesses to always keep the latest enhancements in terms of Microsoft operating systems in their environments.
Finally, for testing and labbing the latest and greatest Windows features and enhancements, the SAC versions of Windows are a great way to see these and play around the newest capabilities that will be found in upcoming LTSC releases. Using the Semi-Annual Channel releases in a lab environment to get a feel for the new features and enhancements allows developing applications and other features to make use of upcoming Windows Server releases that may offer tremendous benefits in production.
What about those environments who are running monolithic, more traditional applications who do not need the latest and greatest features?
Long-Term Servicing Channel (LTSC)
The Long-Term Servicing Channel (LTSC) is the more traditional release channel of Microsoft Windows Server that we are traditionally used to seeing. In fact, the “normal” Windows Server releases such as Windows Server 2012 R2, Windows Server 2016, and Windows Server 2019 are part of the Long-Term Servicing Channel (LTSC) releases.
As already discussed, the SAC versions of Windows Server are released roughly every six months. However, the LTSC releases from Microsoft are typically released every 2-3 years, depending on the schedule outlined from Microsoft. You can think of the Long-Term Servicing Channel (LTSC) releases as basically a version of Microsoft Windows Server that “rolls up” all of the new features released in the Semi-Annual Channel releases that have been introduced since the last LTSC release.
Long-Term Servicing Channel (LTSC) Use Case
For environments that want to deploy more traditional Windows Server roles found in typical SMB to large enterprise environments, the LTSC releases are generally what most will want to use.
The LTSC release channel is used by those who want a longer cycle & predictability and is a good fit for a domain controller, file server, or maybe to host a SQL Server.
Support for Long-Term Servicing Channel (LTSC)
Generally speaking, a major reason to use LTSC versions for these more traditional servers found in the enterprise environment is support. With the LTSC releases, Microsoft offers the more traditional support experience that has been known in all the traditional Windows Server versions in the past. This includes five years of mainstream support and then five years of available extended support for the LTSC versions of Windows.
Microsoft is giving customers more options when it comes to being able to choose the type of support and release cadence they would like to run in production environments. The Semi-Annual Channel (SAC) and Long-Term Servicing Channel (LTSC) releases both offer advantages and use cases.
For those businesses utilizing the more cutting-edge technologies such as containers, the SAC versions of Windows will offer the latest enhancements and allow businesses to effective implement the immutable infrastructure that will not be disrupted by the much faster release cadence found in the SAC channel.
However, for more traditional environments and server roles, the LTSC channel provides perhaps the best fit of features and supportability that most are accustomed to. With LTSC, businesses should be comfortable installing the traditionally long-term roles such as domain controllers, certificate servers, and backend servers such as Microsoft SQL Servers.
Either way, each channel offers great features and advantages that help satisfy multiple use cases in the enterprise. Customers win with more options available to them to solve various technology challenges.