What is Failover clustering? A failover cluster is a resilient feature of Microsoft that can be highly beneficial to businesses. Most of the business functions would like to have their business critical servers powered up all time to steer their productivity. In some cases, an unprecedented disaster can hit their business productivity badly. So here comes Failover cluster.
In Failover cluster, when a business critical server (or) VM (or) application server goes down, the other node in the cluster can take over its workload with minimal downtime. Cluster communication between multiple nodes makes it highly available and reliable. Microsoft Failover Clustering is a concerted system component where the hosts share one or more common networks and when it comes for storage at least one shared storage location, shared disks are accessible for all the nodes in the failover cluster, makes it simple.
So Before you begin to create a failover cluster, you must connect the hardware (servers, networks, and storage) and perform the validation tests. If you have your Hyper-V servers (nodes) grouped together in a failover cluster, virtual machines in the server are considered as roles. Roles not only mean to be virtual machines, also can be configured as a generic script or generic service or application etc.,
For the reason Failover cluster is highly scalable, later if you need another Hyper-V server to be added to the cluster setup, it can be done quite easily without any reconfiguration of the setup using the failover cluster manager wizard.
The event of failover can be a planned one or unplanned, you can switch over to manual failover process (planned) for the server maintenance window timings. The roles will be migrated from one host to another without any downtime. It eventually performs the failover cluster service (unplanned) automatically in a disaster or server crash scenarios.
Cluster Shared Volume
Cluster Shared Volume is one of the reasons that makes the virtual machines or roles in a cluster environment highly available. In this feature, the shared volume gives simultaneous access to all the nodes in the cluster environment and makes the cluster service uninterrupted. It allows multiple nodes to read and write from a single shared storage (or) same LUN.
Cluster Shared Volume (CSV) feature is applicable only for Hyper-V and other technologies that are specified by Microsoft, CSV requires NTFS.
Working with Failover Cluster Manager
Failover cluster manager is a user-friendly administering interface to create – coordinate – monitor the failover clusters from time to time. Using failover cluster manager modifications can be done to the deployed nodes and roles in the failover cluster.
- The Configuration of roles and adding a new server(node) to the cluster can be done in few clicks. Migration of roles can be performed from one node to another possible node in the cluster using the migration options available: Live Migration, Quick Migration
- Right click on the role, select “move” and then select the migration option of your choice
- You can also set/restrict the maximum number of failover in a specific time period for a particular role
- By clicking the properties pane, You can assign the preferred owner node for the cluster roles
- Using the options, the failback event can be prevented or can be assigned to perform automatically to its preferred owner immediately or between a specific time period
What is Cluster operating system rolling upgrade with no downtime? What is Virtual machine load balancing? To get to know, Keep an eye out for our next post on Failover Clustering with the new upgrades in Windows Server 2016 – Virtual machine load balancing, Storage Replica, Cluster Operating System Rolling upgrade, Workgroup and Multi-domain clusters, Virtual Machine resiliency etc.
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