vSphere5 HA feature

The most widely used feature for availability in a virtualized environment is vSphere HA. vSphere HA provides the foundation for a highly available environment by monitoring the virtual machines and the hosts upon which they run.

In vSphere 5.0, the vSphere HA feature has been completely rewritten by VMware from the ground up. This was done to increase the scalability, reliability, and usability of vSphere HA. Each of these factors, and the enhancements incorporated to support them, are described below.

Scalability

With the increased usage of VMware products in today’s modern datacenter comes a need to provide a scalable solution for high availability. The redesign of vSphere HA provides this foundation.

One of the biggest changes with vSphere HA is that the concept of primary and secondary nodes has been completely removed. The new model incorporates a master-slave relationship between the nodes in a cluster, where one node is elected to be a master and the rest are slaves. The master node coordinates all availability actions with the other nodes and is responsible for communicating that state to the VMware vCenter Server. This model eliminates a significant amount of planning in the architecture design of a highly available environment. No longer must administrators worry about what hosts are their primary nodes and where they are located. This is especially significant when implementing vSphere HA on blade chassis and in stretched cluster environments.

The support for IPv6 networking in vSphere HA enables IT departments in need of a larger addresses space to fully leverage their network infrastructure.

vSphere HA now also includes an enhanced deployment mechanism. This enhancement allows administrators to complete tasks in a fraction of the time required previously, such as with deployment of the vSphere HA agent, vSphere HA configure, unconfigure, reconfigure, and so on.

Usability

Although most of the enhancements made to vSphere HA are not visible to the end user, there was a focus on improving the usability.

The user interface has been enhanced to allow for users to quickly identify the role a node in the cluster plays, as well as its state. Messages reporting error conditions have also been made easier to understand and act upon. When problems do occur, there is just one log file that must be reviewed, greatly decreasing the time to resolution.