Azure Site Recovery overview

Article
08/12/2024

Azure Site Recovery on Azure Stack Hub helps ensure business continuity by keeping business apps and workloads running during outages. Azure Site Recovery on Azure Stack Hub replicates virtual machine (VM) workloads from a primary site to a secondary location. When an outage occurs at your primary site, you fail over to a secondary location, and access apps from there. After the primary location is running again, you can fail back to it.

To enable replication of VMs across two Azure Stack Hub stamps, configure the following environments:

Source environment is the Azure Stack Hub stamp where tenant VMs are running.
- Azure Stack Hub Operator, download the Azure Site Recovery Appliance VM and the Azure Site Recovery VM extensions in the Marketplace Management.
- Azure Stack Users, in the user subscriptions, configure the connection to the target vault in this source environment.
Target environment is where the Azure Site Recovery Resource Provider runs.
- Azure Stack Hub Operator, download and install the respective resource provider.
- Azure Stack Hub Users, configure the vault and prepare the prerequisites for your replicated VMs.

Azure Site Recovery on Azure Stack Hub is available for both Microsoft Entra ID and Active Directory Federation Services (AD FS) type deployments of Azure Stack Hub, which means it can run in disconnected environments.

What does Site Recovery provide?

Azure Site Recovery provides many features, as described in the following table.

Feature	Details
BCDR solution	Using Site Recovery, you can set up and manage replication, failover, and failback from a single location in the Azure Stack Hub portal.
BCDR integration	Site Recovery integrates with other BCDR technologies. For example, you can use Site Recovery to protect the SQL Server backend of corporate workloads, with native support for SQL Server Always On, to manage the failover of availability groups.
Azure Automation integration	A rich Azure Automation library provides production-ready, application-specific scripts that can be downloaded and integrated with Site Recovery.
RTO and RPO targets	Keep recovery time objectives (RTO) and recovery point objectives (RPO) within organizational limits. Site Recovery provides continuous replication for Azure Stack Hub VMs.
Keep apps consistent over failover	You can replicate using recovery points with application-consistent snapshots. These snapshots capture disk data, all data in memory, and all transactions in process.
Testing without disruption	You can easily run disaster recovery drills, without affecting ongoing replication.
Flexible failovers	You can run planned failovers for expected outages with zero-data loss or unplanned failovers with minimal data loss, depending on replication frequency, for unexpected disasters. You can easily fail back to your primary site when it's available again.
Customized recovery plans	Not currently available in this version. You can still customize and sequence the failover and recovery of multi-tier applications running on multiple VMs by using PowerShell scripts, tagging machines together in groups, and optionally adding scripts and manual actions.

How is Site Recovery billed?

Azure Site Recovery on Azure Stack Hub is intended to protect a specified number of Virtual Machines. To provide this service at a competitive rate, the cost of Azure Site Recovery is determined based on the physical core count of the target environment, regardless of the number of VMs that are protected. For detailed pricing options, see the Azure Stack Hub pricing details.

When you first install Azure Site Recovery on Azure Stack Hub, a 30-day free trial period is provided. This trial period enables testing, automation setup, and VM replication for protection. Following the conclusion of the 30-day trial, charges begin, calculated on the total count of physical cores in the target environment in which your Azure Site Recovery Resource Provider is installed.

Cloud Solution Providers (CSPs) who offer multi-tenant environments should note that Azure Site Recovery usage is reported only on the primary Azure Stack Hub registration subscription. Any usage from failed-over virtual machines or storage associated with protected VMs is accurately allocated to the customer's respective Azure subscription. The Azure Site Recovery solution's cost (on the target side) is reported only in the subscription used for Azure Stack Hub registration. Typically, this subscription is owned by the CSP offering the multitenant environment. Consequently, the CSP is responsible for determining and appropriately billing each of their customers using Azure Site Recovery.

What can I replicate?

Azure Site Recovery on Azure Stack Hub, with a required agent installed on each of the protected VMs, enables the replication of VMs across two instances, or stamps, of Azure Stack Hub. Azure Stack Hub uses a VM extension, available through the Azure Stack Hub Marketplace, to install this agent.

Note

Azure Site Recovery on Azure Stack Hub can only protect VMs that use managed disks. To convert a currently provisioned VM that uses unmanaged disks to managed disks, you can use the process described in Convert to managed disks.

The following VM OSs were tested and validated, and each has respective Azure Stack Hub Marketplace images available for download:

Windows
Linux

Operating system	Details
Windows Server 2022	Supported.
Windows Server 2019	Supported for Server Core, Server with Desktop Experience.
Windows Server 2016	Supported Server Core, Server with Desktop Experience.
Windows Server 2012 R2	Supported.
Windows Server 2012	Supported.
Windows Server 2008 R2 with SP1/SP2	Supported. From version 9.30 of the Mobility service extension for Azure VMs, you need to install a Windows servicing stack update (SSU) and SHA-2 update on machines running Windows Server 2008 R2 SP1/SP2. SHA-1 isn't supported from September 2019, and if SHA-2 code signing isn't enabled the agent extension won't install or upgrade as expected. For more information, see SHA-2 upgrade and requirements.
Windows 10 (x64)	Supported.
Windows 8.1 (x64)	Supported.
Windows 8 (x64)	Supported.
Windows 7 (x64) with SP1 onwards	Supported. From version 9.30 of the mobility service extension for Azure VMs, install a Windows servicing stack update (SSU) and SHA-2 update on machines running Windows 7 with SP1. From September 2019, SHA-1 isn't supported, and if SHA-2 code signing isn't enabled the agent extension won't install or upgrade as expected. For more information, see SHA-2 upgrade and requirements.

Operating system	Details
Red Hat Enterprise Linux	6.7, 6.8, 6.9, 6.10, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4 (4.18.0-305.30.1.el8_4.x86_64 or higher), 8.5 (4.18.0-348.5.1.el8_5.x86_64 or higher), 8.6, and 8.7.
Ubuntu 14.04 LTS Server	Includes support for all 14.04.x versions. Supported kernel versions.
Ubuntu 16.04 LTS Server	Includes support for all 16.04.x versions. Supported kernel version. Ubuntu servers using password-based authentication and sign-in, and the cloud-init package to configure cloud VMs, might have password-based sign-in disabled on failover, depending on the cloud-init configuration. Password-based sign-in, of the failover VM in Azure portal, can be re-enabled on the virtual machine by resetting the password from the Support > Troubleshooting > Settings menu.
Ubuntu 18.04 LTS Server	Includes support for all 18.04.x versions. Supported kernel version. Ubuntu servers using password-based authentication and sign-in, and the cloud-init package to configure cloud VMs, might have password-based sign-in disabled on failover, depending on the cloud-init configuration. Password-based sign-in, of the failover VM in Azure portal, can be re-enabled on the virtual machine by resetting the password from the Support > Troubleshooting > Settings menu.
Ubuntu 20.04 LTS server	Includes support for all 20.04.x versions. Supported kernel version.
Debian 7	Includes support for versions starting with 7.4 and later (7.2 and earlier are not supported due to a limitation in that version).
Debian 8	Includes support for all 8. x versions. Supported kernel versions.
Debian 9	Includes support for 9.1 to 9.13. Debian 9.0 isn't supported. Supported kernel versions.
Debian 10	Supported kernel versions.
Debian 11	Supported kernel versions.
SUSE Linux Enterprise Server 11	SP3. The upgrade of replicating machines from SP3 to SP4 isn't supported. If a replicated machine was upgraded, you must disable replication and re-enable replication after the upgrade.
SUSE Linux Enterprise Server 11	SP4
SUSE Linux Enterprise Server 12	SP1, SP2, SP3, SP4, and SP5. Supported kernel versions.
SUSE Linux Enterprise Server 15	15, SP1, SP2, SP3, and SP4. Supported kernel versions.
Oracle Linux	6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 6.10, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3 (running the Red Hat compatible kernel or Unbreakable Enterprise Kernel Release 3, 4, 5, and 6 (UEK3, UEK4, UEK5, UEK6)), and 8.4, 8.5, 8.6, and 8.7. 8.1 (running on all UEK kernels and RedHat kernel greater than or equal to 3.10.0-10620 are supported in 9.35). Support for rest of the RedHat kernels is available in 9.36.

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Azure Site Recovery on Azure Stack Hub capacity planning

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Azure Site Recovery overview

What does Site Recovery provide?

How is Site Recovery billed?

What can I replicate?

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