I can't afford to build a failover cluster. Are there any other options for providing fault tolerance?
Historically, the only way to make Microsoft Hyper-V virtual machines fault tolerant was to build a host server cluster. The problem with using failover clustering was that it required the use of a Cluster Shared Volume (CSV), which is expensive, to say the least. This requirement put Hyper-V clustering beyond the financial reach of many small and medium-sized businesses.
Windows Server 2012 offers some lower cost alternatives to traditional Hyper-V clustering. One of the biggest changes that Microsoft has made in the new version is to remove the requirement for clusters to depend on a CSV. It is now possible to build a failover Hyper-V cluster without using shared storage. All you need is enough local storage in each cluster node to accommodate the VMs.
Another option is something called Microsoft Hyper-V Replica. Replication is similar to clustering, but it isn't a true clustering solution. When Hyper-V Replica is enabled, VMs (or rather the virtual hard drives that make up the VMs) are replicated from one Hyper-V host to another. The replica doesn't provide the same level of failover protection that a true cluster does, but you can manually perform both planned and unplanned failovers.
Another nice thing about the Hyper-V Replica feature is that you can create replicas using a minimum of two servers (a source server and a target server). Failover clusters require a minimum of three servers (either three cluster nodes or two cluster nodes and a file share witness). Being able to create a replica based on only two servers helps to reduce costs compared to failover clustering.
New VM replication tool for IT shops
Disaster recovery options for SMBs
Hyper-V Replica takes center stage at WPC 2011
Dig deeper on Disaster recovery, failover and high availability for virtual servers
Related Q&A from Brien Posey
Brien Posey explains the benefits of the Resilient File System and examines the reasons why it has remained relatively unused.continue reading
Boot to VHD may be seen as a novelty feature, but it also has practical uses in the workplace. Brien Posey explains in this expert answer.continue reading
Expert Brien Posey explains the importance of application-aware checkpoints and how they differ from hypervisor snapshots.continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.