How to update VM OS?

Question

How to update VM OS?

Souheil El-Hage 0

Hi, I have a VM that is running EOL OS. The OS is Linux (centos 8.3.2011) that reached EOL.

How can I perform upgrades to latest OS?

Thanks

Ankit Yadav 14,255 Reputation points Microsoft External Staff Moderator

2026-05-07T04:25:12.4266667+00:00
Hi Souheil,

Since your VM is running CentOS 8 (which has reached end of life), it will no longer receive security updates or patches. To remain supported and secure, you will need to move your workload to a supported operating system.

At a high level, Azure does not provide a native “one‑click” OS upgrade for Linux virtual machines. OS upgrades are handled at the distribution level, and the available options depend on the target distribution you choose.

You can consider the following supported approaches:

Option 1: Migrate to another supported Linux distribution You can transition your workload to a currently supported operating system. Common options include:

Red Hat Enterprise Linux (RHEL)

AlmaLinux or Rocky Linux (community alternatives compatible with CentOS)

Oracle Linux or other supported distributions

Some of these distributions provide their own tools for in‑place conversion. If you choose this approach, the conversion process and tooling are provided and supported by the distribution vendor, not Azure.

Option 2: Redeploy a new VM with a supported image (recommended) Microsoft generally recommends creating a new VM using a supported OS image from the Azure Marketplace and migrating your workload. This approach:

Ensures a clean and fully supported configuration

Avoids potential issues during in‑place conversion

Keeps compatibility with Azure platform features and update services

Typical steps include:

Deploy a new VM with a supported OS image

Attach or copy your data disks

Reinstall/configure your application

Validate functionality and perform cutover

Additional notes

Services like Azure Update Manager are used for applying patches within a supported OS, but they do not upgrade an OS from one distribution or major version to another.

Continuing to run an EOL OS is not recommended, as it no longer receives security or maintenance updates.

References

https://learn.microsoft.com/en-us/azure/virtual-machines/workloads/centos/centos-end-of-life

https://learn.microsoft.com/en-us/azure/update-manager/support-matrix-updates
Ankit Yadav 14,255 Reputation points Microsoft External Staff Moderator

2026-05-11T09:59:07.5533333+00:00

Hi Souheil,

I wanted to check if you’ve had a chance to look over our earlier response.

Please let us know if you have any further questions.

1 answer

Your answer

Ankit Yadav 14,255 Reputation points Microsoft External Staff Moderator

2026-05-11T09:59:07.5533333+00:00

Hi Souheil,

I wanted to check if you’ve had a chance to look over our earlier response.

Please let us know if you have any further questions.

Answer 1

CentOS 8.3.2011 is end-of-life, so there are two main options in Azure:

Stay CentOS-compatible (in-place conversion)
- Pick a CentOS-compatible distribution such as Red Hat Enterprise Linux, AlmaLinux, Oracle Linux, or Rocky Linux.
- Use that distribution’s conversion/migration tooling to convert the existing VM in place. Many of these tools replace CentOS packages and update repositories while keeping data and configuration:
  - Red Hat Enterprise Linux: a conversion tool is available from Red Hat.
  - AlmaLinux: provides a migration guide and conversion tool.
  - Oracle Linux: provides migration tooling and guidance.
  - Rocky Linux: provides a migrate2rocky conversion tool.
- Before conversion:
  - Take a backup of the VM or a snapshot of the OS disk.
  - Ensure the VM was created from an image that does not embed software billing information (for example, a custom image or the OpenLogic CentOS Marketplace image). If the image has a price associated, converting in place may result in double-paying (original image plus new subscription).
- After conversion, use the new distribution’s package manager to keep the OS updated.
Redeploy to a new OS (recommended for Azure integration)
- Create a new Azure VM using a supported, endorsed Linux distribution image (for example, RHEL, AlmaLinux, Rocky Linux, etc.).
- Deploy applications and restore data to the new VM.
- Cut over traffic/workloads to the new VM and decommission the old CentOS VM.
- This approach keeps the Azure control plane aligned with the VM OS so that Azure features such as automatic guest patching, automatic OS image upgrades, hotpatching, and Azure Update Manager remain available.

If an in-place major version upgrade is performed after migration (for example, CentOS 7 → RHEL 7 → RHEL 8) instead of redeploying, Azure control-plane features like automatic guest patching, automatic OS image upgrades, hotpatching, and Azure Update Manager will not be available. In such cases, creating a new VM with the target OS is recommended.

References:

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How to update VM OS?

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