Azure Site Recovery: Disaster Recovery as a Service (DRaaS) for Azure, by Azure | Azure Blog

Azure is the first public cloud to offer native disaster recovery solution for applications running on IaaS. We want to start this year with a recap of all the new capabilities that we enabled in the last few months that customers have loved.

This blog was co-authored by Sujay Talasila, Senior Program Manager, Cloud + Enterprise.

Microsoft Azure is the first public cloud to offer native disaster recovery (DR) solution for applications running on IaaS virtual machines (VMs). Six months ago, we announced the general availability of DR for Azure VMs using Azure Site Recovery (ASR). Since then we have been heavily invested on ensuring that the customer experience of using this DR capability is nothing less than the best. Being a service that is used by thousands of customers, there are two key principles based on which we make decisions on what features and updates to invest in.

Continue to stand as a fully integrated offering.

Customers can enable the DR capability and carry out all related operations. These operations include testing the DR drill or performing the actual failover, all from the Azure portal with minimal clicks. This also translates to ensuring that ASR is updated with support for the newest Azure features as they’re released.

Make continued improvements and democratize DR.

We are constantly working to improve the site recovery service, absorbing the complexities of setting up DR into the service so that as a customer, you need to make minimal decisions. This involves continuously listening to feedback and ensuring that we make enhancements to the service to help customers scale effortlessly while supporting different types of workloads. We also adhere to a once a month service update rhythm so that customers can start using the latest features as soon as possible. Any improvements needed in the service are also in this way, made available as soon as we can.

We want to start this year with a recap of all the new capabilities that we enabled in the last few months that customers have loved.

Support for zone pinned Azure VMs: For IaaS applications running on Azure VMs, you can build high availability into your business continuity strategy by deploying multiple VMs across multiple zones within a region. As announced in December 2018, customers can replicate and failover zone pinned virtual machines to other regions within a geographic cluster using ASR. This new capability is generally available in all regions supporting Availability Zones. Along with Availability Sets and Availability Zones, ASR completes the resiliency continuum for applications running on Azure VMs.
DR of Azure Disk Encryption-enabled VMs: We now support DR for Azure Disk Encryption-enabled VMs to safeguard data according to your company’s security and compliance needs. You can replicate VMs, enabled for encryption through the Azure Active Directory app, from one Azure region to another region. For more details, see the Azure Service Update, “Disaster recovery for Azure Disk Encryption–enabled virtual machines.”
Support for fire-wall enabled storage accounts: Support for firewall-enabled storage accounts was recently enabled. You can replicate VMs with unmanaged disks on firewall-enabled storage accounts to another Azure region for disaster recovery scenarios. You can also select firewall-enabled storage accounts in a target region as target storage accounts for unmanaged disks. You can restrict access to the cache storage account by allowing only the source Azure VM's virtual network to write to it. When you're using firewall enabled storage accounts, ensure that you enable the “allow trusted Microsoft services,” exception.
Accelerated networking support: Accelerated networking enables single root I/O virtualization (SR-IOV) to a VM, greatly improving its networking performance. This high-performance path bypasses the host from the data path, reducing latency, jitter, and CPU utilization, for use with the most demanding network workloads on supported VM types. ASR enables you to utilize the benefits of accelerated networking, for Azure VMs that are failed over to a different Azure region. The documentation, “Accelerated Networking with Azure virtual machine disaster recovery,” describes how you can enable accelerated networking for Azure VMs replicated with ASR.
Automatic Site Recovery extension updates: One of the biggest hassles faced by administrators while using services provided by cloud providers is the need to catch up with the latest release and stay up to date. This involves downloading the latest software and performing frequent upgrades. In an enterprise scenario, this means going through a various level of approvals and wait time before you can make any changes. It becomes even more cumbersome if downtime is involved. You no longer need to plan for deploying the new versions with every release, and automatic updates do not require a reboot of your Azure VMs, nor does it affect on-going replication. You can enable ASR automatic updates and ensure your VMs to get the latest updates as soon as they are released.
Support for Standard SSD Disks: The Azure Standard SSD Disks are a cost-effective storage option optimized for workloads that need consistent performance at lower IOPS level. Standard SSD disks deliver better availability and latency compared to HDD Disks. ASR supports replication and failover of Azure VMs using Standard SSD disks to another region. By default, ASR retains the original disk type in the target region. The customer can choose a different disk type while configuring disaster recovery.
Support for Linux OS: ASR supports a wide variety of Linux OS versions. We added support for the below Linux flavors in the last six months.

ASR started supporting RedHat Enterprise Linux (RHEL) and CentOS 7.5, 6.10, and 7.6 from July 2018, August 2018, January 2019, and onward.
Support for SUSE Linux Enterprise Server 12 (up to SP3) was added in July 2018.
ASR started supporting CentOS 6.10 from August 2018 onward.
Latest versions of Oracle Enterprise Linux versions 6.8, 6.9, 7.0, to 7.5, and UEK Release 5 was added for support in November 2018, followed by OEL versions 6.10 and 7.6 in January 2019.
For Ubuntu, SUSE Linux Enterprise Server 12 and Debian OS versions, we release frequent updates to certify and support the latest kernel versions to avoid any breaking changes with ASR mobility service extension. We certify support for latest kernels within 15 to 30 days of their release by Linux distribution vendor.

Protect Azure VMs using Storage Spaces Direct: You can now use ASR to protect IaaS application using storage spaces direct (S2D) for high availability. Storage spaces direct and ASR together provide comprehensive protection of your IaaS workload on Azure. S2D lets you host a guest cluster on Microsoft Azure which is especially useful in scenarios where VM hosting a critical application such as SAP ASCS layer, SQL Server or Scale-out file server.
Pricing calculator for Azure Virtual Machine DR: You can use the sample cost calculator for estimating DR costs for your applications running Azure VMs. To see how the pricing would change for your particular use case, change the appropriate variables to estimate the cost. You can key in the number of VMs for the ASR license cost. You can use the number of managed disks, along with type, and the total data change rate expected across all the VMs to get the estimated storage costs in DR region. Additionally, you can use the total data change rate in a month after applying the compression factor of 0.4 to get the bandwidth costs incurred for transferring data between regions. For more details, refer to the related blog post, “Know exactly how much it will cost for enabling DR to your Azure VMs.”

While we already have a bunch of new exciting features planned for the next few months, do let us know how we can make your DR experiences even better via User Voice.

Azure natively provides you the high availability and reliability for your mission-critical workloads, and you can choose to level up your protection and meet compliance requirements using the disaster recovery provided by ASR. Getting started with Azure Site Recovery is easy – simply check out the pricing information, and sign up for a free Azure trial. You can also visit the Azure Site Recovery forum on MSDN for additional information and to engage with other customers.

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