# Check the kernel series before relying on Site Recovery's support target

> What does the thirty-day Linux kernel support target actually cover for Azure-to-Azure disaster recovery?

- Canonical URL: https://update.dsesecurity.com/updates/dse-20260909-432-check-the-kernel-series-before-relying-on-site-recovery-s-support-target/
- Publisher: Detection Systems & Engineering (DSE Security)
- Author: DSE Security Editorial Team
- Published: 2026-09-10T00:24:44+00:00
- Modified: 2026-09-10T02:04:57+00:00
- Last reviewed by DSE: 2026-09-09
- Resource type: Guide
- DSE priority: Information
- Topics: Business Continuity, Networks & Infrastructure
- Reading time: 2 minutes

## What you need to know

What does the thirty-day Linux kernel support target actually cover for Azure-to-Azure disaster recovery?

## Potentially affected

Apply this check before approving a kernel update on an Azure VM protected to another Azure region. Record the distribution release, kernel series, proposed kernel, and Mobility agent version; a familiar distribution name alone should not settle the support decision.

## DSE recommendation

Maintain an explicit compatibility hold point in the patch record.

## Article

## Source facts

For Azure-to-Azure disaster recovery, Microsoft describes Mobility agent hotfixes for newly released Linux kernels on a best-effort basis within thirty days. This is not a service-level agreement, and only the listed scenarios qualify. For Ubuntu, the described case is a new Azure (-Azure) or generic (-generic) kernel within an already supported series and supported Ubuntu version. A newly introduced kernel series or major operating-system version is outside that case. Custom Linux kernels are unsupported. [Microsoft Learn](https://learn.microsoft.com/en-us/azure/site-recovery/azure-to-azure-support-matrix).

## Applicability

Apply this check before approving a kernel update on an Azure VM protected to another Azure region. Record the distribution release, kernel series, proposed kernel, and Mobility agent version; a familiar distribution name alone should not settle the support decision.

## DSE recommendation

Maintain an explicit compatibility hold point in the patch record. Compare the proposed kernel with Microsoft’s current supported-kernel information, not a calendar estimate based on its release date. If the change introduces a new series or distribution version, obtain the applicable support evidence before treating it as routine patch maintenance.

## Verification

Check the exact installed kernel and agent after the approved update and review replication health. Retain the source entry used for the compatibility decision, along with any unresolved exception. Do not translate thirty elapsed days into automatic approval or describe a best-effort target as guaranteed coverage.

## Official references

[Microsoft Learn: Support Matrix for Azure VM Disaster Recovery with Azure Site Recovery](https://learn.microsoft.com/en-us/azure/site-recovery/azure-to-azure-support-matrix).

## Primary reference

- Name: Support Matrix for Azure VM Disaster Recovery with Azure Site Recovery - Azure Site Recovery | Microsoft Learn
- Authority: Microsoft Learn
- URL: https://learn.microsoft.com/en-us/azure/site-recovery/azure-to-azure-support-matrix
- Source publication date: Not stated by the source

## Citation and use

Preferred citation: “Check the kernel series before relying on Site Recovery's support target,” DSE Security, https://update.dsesecurity.com/updates/dse-20260909-432-check-the-kernel-series-before-relying-on-site-recovery-s-support-target/
Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/
Usage and citation policy: https://update.dsesecurity.com/usage/
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