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.
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.
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.
Review the official source
Support Matrix for Azure VM Disaster Recovery with Azure Site Recovery - Azure Site Recovery | Microsoft Learn · Verified September 9, 2026
Need help applying this guidance safely?
DSE can help confirm applicability, protect service continuity, and validate the result across physical security and IT systems.
Talk with DSE