Category Archives: Microsoft Azure

Windows Server 2016: What's New in Failover Clustering

Very frequently in order to ensure the high availability and business continuity for critical applications and services you need to implement a Failover Cluster running Microsoft. In this article we'll delve into the main innovations introduced with Windows Server 2016 in the failover clustering and analyse the advantages in adopting the latest technology.

Cluster Operating System Rolling Upgrade

In Windows Server 2016 introduces an important feature that allows you to upgrade the nodes of a Hyper-V cluster or Scale-Out File Server from Windows Server 2012 R2 to Windows Server 2016 without any disruption and avoiding to stop it hosted workloads.

The upgrade process involves these steps:

Put the node that you want to update paused and move all the virtual machine or the other workloads on the other nodes in the cluster
Remove the node from the cluster and perform a clean installation of Windows Server 2016
Add the node Windows Server 2016 the existing cluster. By this time the Mixed mode cluster with both Windows Server nodes 2012 R2 and nodes Windows Server 2016. In this connection it is well to specify that the cluster will continue to provide the services in Windows Server 2012 R2 and will not be yet available features introduced in Windows Server 2016. At this stage you can add and remove nodes is Windows Server 2012 R2 and nodes Windows Server 2016
Upgrading of all the cluster nodes in the same way as previously described
Only when all cluster nodes have been upgraded to Windows Server 2016 You can change the functional level to Windows Server cluster 2016. This operation is not reversible and to complete it you must use the PowerShell Update-ClusterFunctionalLevel. After you run this command you can reap all the benefits introduced in Windows Server 2016 stated below

Cloud Witness

Windows Server 2016 introduces the ability to configure the cluster witness directly in Microsoft Azure cloud. Cloud Witness, just like the tall types of witness, will provide a vote by participating in the calculation of quorum arbitrary.

Figure 1 – Cloud Witness in Failover Cluster Manager

Configuring the Cloud Witness involves two simple steps:

Creating a subscription to an Azure Storage Account that you will use Azure Cloud Witness
Configuring the Cloud Witness in one of the following ways

PowerShell

Failover Cluster Manager

Figure 2 – Cloud Witness Configuration Step 1

Figure 3 – Cloud Witness Configuration Step 2

Figure 4 – Cloud Witness Configuration Step 3

The use of Cloud Witness gets the following benefits:

Leverages Microsoft Azure eliminating the need for an additional separate data center for certain cluster configurations
Working directly with a Microsoft Azure Blob Storage canceling this way the administrative effort required to keep a virtual machine in a public cloud
The same Microsoft Azure Storage Account can be used for multiple clusters
View the mole little data that is written to the Storage Account service charge is ridiculous

Site-Aware Failover Clusters

Windows Server 2016 introduces the concept of clustered failover site-aware and is able to gather groups of nodes in a cluster based on the geographical location configuration stretched (site). During the lifetime of a cluster site-aware placement policies, the heartbeat between nodes and failover operations and calculation of the quorum are designed and improved for this particular cluster environment configuration. For more details about I invite you to consult the article Site-aware Failover Clusters in Windows Server 2016.

Multi-domain and workgroup Cluster

In Windows Server 2012 R2 and in previous versions of Windows, all nodes in a cluster must necessarily belong to the same Active Directory domain. With Windows Server 2016 removes these barriers and provides the ability to create a Failover Cluster without Active Directory dependencies.

In Windows Server 2016 supports the following configurations:

Single-domain Cluster: clusters where all nodes are in the same domain
Multi-domain Cluster: cluster composed of nodes joined to different Active Directory domains
Workgroup Cluster: cluster with nodes in WFWG (not joined to a domain)

In this regard it is good to specify what are the supported workloads and its limitations to Multi-domain and Workgroup cluster:

Cluster Workload	Support	DettagliMotivazione
SQL Server	Supported	Recommended SQL Server authentication.
File Server	Supported, but not recommended	Kerberos authentication (not available in these environments) is the recommended authentication protocol Server Message Block traffic (SMB).
Hyper-V	Supported, but not recommended	Does not support Live Migration, but only the Quick Migration.
Message Queuing (MSMQ)	Not supported	Message Queuing save property in AD DS.

Diagnostic in Failover Clustering

In Windows Server 2016 the following innovations have been introduced to facilitate troubleshooting if problems arise cluster environment:

Several improvements have been made to the cluster log (as the information about the Time Zone and the channel DiagnosticVerbose) making it more easily accessible and more information. For more details about I invite you to consult the article Windows Server 2016 Failover Cluster Troubleshooting Enhancements – Cluster Log
A new dump file of type Active memory dump, useful Hyper-V clusters, can filter out many pages of memory allocated by virtual machines. This mechanism then generates a file memory.dmp of considerably smaller. More details can be found in Windows Server 2016 Failover Cluster Troubleshooting Enhancements – Active Dump

SMB Multichannel and Multi-NIC Cluster Network

In Windows Server 2016 There are several new features in the network regarding the clustered environment that help ease configuration and get better performance.

The main benefits introduced in Windows Server 2016 can be summarised in the following points:

SMB Multichannel is enabled by default
Failover cluster can recognize automatically the NIC attested on the same subnet as the same switch
A single resource IP Address is configured for each Access Point Cluster (Zip code) Network Name (NN)
The network with Link-Local IPv6 addresses only (FE80) are recognized as private networks (cluster only)
The cluster validation does not report more warning messages in case there are more NIC attested on the same subnet

For more information I refer you to the Microsoft documentation: Simplified SMB Multichannel and Multi-NIC Cluster Networks.

Conclusions

Windows Server 2016 introduces major changes in the Failover Clustering making the solution more flexible and opening up new configuration scenarios. Furthermore the upgrade process allows us to easily update existing clusters to take advantage of all the benefits introduced by Windows Server 2016 for different workloads.

OMS Azure Site Recovery: solution overview

To have an adequate business continuity and disaster recovery strategy that helps keep running applications and restore normal working conditions when it is necessary to perform maintenance activities planned or unplanned stoppages is crucial.

Azure Site Recovery promotes l ’ implementation of these strategies by orchestrating the replicas of virtual machines and physical servers present in your data center. You have the option of replicating servers and virtual machines that reside on a local primary data center to the cloud (Microsoft Azure) or to a secondary data center.

If you experience interruptions in the primary data center you can initiate a failover process to keep workloads accessible and available. When will it be possible to use the resources in the primary data center will handle the failback process.

Replication scenarios

The following scenarios are covered in Azure replication Site Recovery:

Hyper-V virtual machine replication

In this scenario if Hyper-V virtual machines are managed by System Center Virtual Machine Manager (VMM) You can expect the replica to a secondary data center and Microsoft Azure. If the virtual machines are managed through VMM, the replica will be possible only to Microsoft Azure.

Replication of VMware virtual machines

The virtual machines on VMware can be replicated to a secondary data center using a data channel of InMage Scout to Microsoft Azure.

Replication of physical servers Windows and Linux

The physical servers can be replicated to a secondary data center (using InMage Scout data channel) that to Microsoft Azure.

Figure 1 – Replication scenarios of ASR

Azure configuration Site Recovery

The following table lists the documents with the specifications that you must follow to configure Azure Site Recovery in different scenarios:

Typology of the systems to be replicated	Replication target
VMware virtual machines	Microsoft Azure Secondary data center
Managed Hyper-V virtual machines in VMM clouds	Microsoft Azure Secondary data center
Managed Hyper-V virtual machines in VMM clouds, with storage on SAN	Secondary data center
Hyper-V virtual machines without VMM	Microsoft Azure
Local Windows/Linux physical servers	Microsoft Azure Secondary data center

The main advantages in adopting Azure Site Recovery

After reviewing what can I do with Azure Site Recovery and what steps to follow to implement recovery plans are those that are some of the major benefits that you may have with the adoption of this solution:

Using the tools of Azure Site Recovery it simplifies the process of creating business continuity and disaster recovery plans. Recovery plans and runbooks can include scripts present in Azure Automation so you can shape and customize your application with DR procedures for complex architectures.
You can have a high degree of flexibility thanks to the potential of the solution that enables you to orchestrate replicas of physical servers and virtual machines running on Hyper-V and VMware.
With the ability to replicate the work loads directly on Azure in some cases you may want to completely delete a secondary data center made just for business continuity and disaster recovery.
You have the option to periodically perform failover test to validate the effectiveness of the recovery plans implemented, without giving any impact to production application environment.
It is possible to integrate with other technologies existing company ASR BCDR (for example Sql Server AlwaysOn or SAN replication).

Types of Failover on Azure Site Recovery

After creating a plan of recovery you can perform different types of failover. The following table lists the various types of failover and for each is specified its purpose and what action causes the execution process.

Conclusions

Azure Site Recovery is a powerful and flexible solution for creating business continuity and disaster recovery strategies for your data center, able to orchestrate and manage complex and heterogeneous infrastructures. All this makes ASR an appropriate tool for most environments. For those wishing to explore the field of Azure Site Recovery features can activate a trial of environment Operations Management Suite or of Microsoft Azure.

Microsoft Azure Site Recovery: Hyper-V virtual machine replication in Microsoft Azure

Microsoft Azure Site Recovery provides the ability to replicate virtual machines on Hyper-V towards a specific cloud service for disaster recovery.

By accessing the following link you can see all the details about prerequisites and about supported scenarios for using Azure Site Recovery: http://msdn.microsoft.com/it-it/library/azure/dn469078.aspx Continue reading →