This document describes the lifecycle of an operating system (OS) version,starting from its creation through to its end of lifecycle (EOL) stage.

An OS version transitions through two main stages as part of itslifecycle:

1. Mainstream support or general availability (GA)

2. Deprecated or end of support (EOS): which is further divided into thefollowing two sub-stages:

   1. Extended support
   2. End of lifecycle (EOL)

For some OS versions, after they are marked deprecated, they might also have anextended support phase before they reach full EOL.

The following sections outline the lifecycle stages of an OS version onCompute Engine.

Mainstream support or general availability (GA)

In this stage the following processes take place:

1. With the introduction of a new OS version, the OS image provider creates anew OS image and assigns a name by using the naming convention for that OSdistribution. For example,debian-11-bullseye-v20230801.

2. The image provider then creates a new image family. For example,debian-11.

   Image families help you manage OS images in yourproject by grouping related images together, so that you can roll forward androll back between specific OS image versions. For more information, seeImage families best practices.

   All calls to the image family references this recently created OS image.For example, if you specify an image family during VM creation byusing the--image-family flag with the appropriate--image-project, thenthe latest version of the image is used.

3. Occasionally, the image provider applies critical security or bugfixes, that are sent by the OS provider, to the OS image. In these updates,new features might be introduced.When an update is sent, the following takes place:

   • The current OS image is updated and a new name is generated. Forexample, thedebian-11-bullseye-v20230801 with the updates becomesdebian-11-bullseye-v20230901.
   • Thedebian-11 image family now points to the newdebian-11-bullseye-v20230901 OS image.
   • The previous OS image (debian-11-bullseye-v20230801) is markeddeprecated.

Deprecated or End of Support (EOS)

At some point, each OS version reaches the deprecation phase. For OS versiondeprecation dates, seeOperating system details.

Deprecated OS versions can either be in an extended supported or end oflifecycle phase.

In this stage, OS providers stop providing image updates and the OS images aremarked deprecated. You might still be able to use these OS images, but you areresponsible for acquiring updates, which are subject to availability from theOS distribution, vendor, or open source community.

When an OS version reaches EOS, the following takes place:

• The latest image in the image family is either deleted or marked deprecated.

• You can no longer use the image family. However, you can stilluse some or all of the OS images by referencing them directly with theexception of Windows where all OS images are deleted at EOS.

  To create a VM from a deprecated image, you must use thegcloud CLI or REST. When specifying the image,you must use the--image flag because image families don't point todeprecated images. For more information about creating VMs, seeCreate a VM instance from a public image.

• When an OS version reaches or goes past the extended lifecycle stage, Googledoesn't guarantee feature compatibility with new machine families or CPUplatforms, to these deprecated versions.

  All VMs that use OS images that belong to this EOS OS version continue to work on Compute Engine and are still eligible forGoogle Cloud support beyond their EOS date. However, if any issues with the VM is identified to be associated with the deprecated OS version, Google might not be able to resolve the issue as OS provider support is no longer available.

Deprecated OS versions can either be in an extended supported phase or end oflifecycle.

Extended support

For some operating systems, when they reach the deprecation phase,OS distributors provide a maintenance, extended or long-term paid package thatcan be applied to your OS:

• For Red Hat Enterprise Linux (RHEL) OS: Maintenance support, Extended life phase,Extended Lifecycle support ELS (Add-On), or Extended Update Support (EUS)
• For Rocky Linux: Long Term Support can bepurchased from CIQ
• For SUSE Linux Enterprise Server (SLES) OS:Long Term Service Pack Support, Extended Service Pack Overlap Support (ESPOS)
• For Ubuntu Pro OS: Extended Security Maintenance (ESM)
• For Windows OS: Extended Security Updates

For more details on these extended lifecycle packages, see the documentation forthe OS provider.

End of lifecycle (EOL)

For operating systems that have reached the end of the extended support period,or operating systems that don't support an extended support period, thefollowing takes place:

• The latest image in the image family is marked deprecated, or is deletedfrom Google Cloud.

• The guest environment software provided by Google won't beupdated for EOL OS versions, and repositories are no longer updated or maintained.

• For existing VMs that use EOL OS versions, the following takes place:

  • The VM can't download or install software packages or updates from the OSvendor and security updates are no longer available. This occurs becausecontent from the OS vendor might no longer be available from the existingchannels as the configured software repository infrastructure fromthe OS vendor might be turned down or archived.
  • The VM continues to run but continued compatibility is not guaranteed.Active support might not be available from the OS vendor or Google. Googlecan provide options for migration or upgrades to newer OS versions.

OS image naming convention, update schedule, and deprecation policy

The following table outlines the naming convention for OS imagesand image families, the update schedule, and the applicable EOSpolicy.

Definitions

The following notations are used in the table:

• V is the numeric version for the OS. For exampleRHEL-7 where7 is thenumeric version
• R is the release string sometimes referred to as the development codenamefor the OS. For example,debian-12-bookworm-v20240213 wherebookwormis the release string.Release strings only apply to Debian and Ubuntu OS images.
• N is the numeric build number.Build numbers only apply toContainer-Optimized OS and Fedora CoreOS.
• YYYYMMDD is the Year/Month/Day that identifies the date that theOS image was built or published. For some OS, the date is preceded by alowercasev. For example,vYYYYMMDD.

What's next

• Learn more about theoperating systemsthat are available on Compute Engine.