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Microsoft Demos Disaster Recovery Feature Slated for Windows Server

In its latest bid to offer better failover and replication in its software and cloud infrastructure, Microsoft demonstrated its new Storage Replica technology at last week's TechEd conference in Barcelona.

Microsoft Principal Program Manager Jeff Woolsey demonstrated Storage Replica during the opening TechEd keynote. Storage Replica, which Microsoft sometimes calls Windows Volume Replication (or WVR) provides block-level, synchronous replication between servers or cluster to provide disaster recovery, according to a Microsoft white paper published last month. The new replication engine is storage-agnostic and Microsoft says it can also stretch a failover cluster for high availability.

Most notable is that Storage Replica provides synchronous replication, which as Microsoft describes it, enables organizations to mirror data within the datacenter with "crash-consistent volumes." The result, says Microsoft, is zero data loss at the file system level. By comparison, asynchronous replication, which Microsoft added to Windows Server 2012 via the Hyper-V Replica and updated in last year's Windows Server 2012 R2 release, allows site extension beyond the limitations of a local metropolitan area. Asynchronous replication, which has a higher possibility for data loss or delay, may not be suited for scenarios where instantaneous real-time availability is a requirement, though for general purposes it's considered adequate.

In the TechEd demo, Woolsey simulated a scenario with four server nodes, two in New York and the other across the river in New Jersey. The goal is to ensure that if users are unable to access data on the two nodes in New York, they automatically and transparently fail over to New Jersey without losing any data, Woolsey explained. It also uses a new feature in the Microsoft Azure service called Cloud Witness.

"To do a stretch cluster you need to have a vote for the cluster quorum," Woolsey explained. "In the past, this meant extra hardware, extra infrastructure, extra cost. Now we're just making this part of Azure as well. So that's an option to take advantage of the Cloud Witness. As you can see, we're baking hybrid capabilities right into Windows Server."

In the demo, Woolsey accessed the file share data to enable replication via the new storage replication wizard. From there he selected the source log disk, then the destination storage volume and log disk. "Literally in just a few clicks, that's it, I've gone ahead and I've set up synchronous replication," he said.

In the recently published white paper, the following features are implemented in the Windows Server Technical Preview:








Yes (server to server only)

Storage hardware agnostic


Replication unit

Volume (Partition)

Windows Server Stretch Cluster creation


Write order consistency across volumes







iWARP, InfiniBand*

Replication network port firewall requirements

Single IANA port (TCP 445 or 5445)


Yes (SMB3)

Kerberos support


Over the wire encryption and signing

Yes (SMB3)

Per-volume failovers allowed


Dedup & BitLocker volume support


Management UI in-box

Windows PowerShell, Failover Cluster Manager

Source: Microsoft

Microsoft also has emphasized that Storage Replica is not intended for backup and recovery scenarios. And because of the general purpose of the product, the company noted it may not be suited to specific applications behaviors. In addition, Microsoft is warning that with Storage Replica, organizations could see feature gaps in applications and hence they could be better served by those app-specific replication technologies.

What's your take on Microsoft's latest efforts to embed disaster recovery into Windows Server and Azure?


Posted by Jeffrey Schwartz on 11/03/2014 at 1:26 PM


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