In this growing world of virtualization, there are many options to consider when it comes to disaster recovery and high availability. With a high percentage of most datacenters now consisting of virtual machines it is relatively easy to keep workloads running, or at least restore them operation very quickly, when a single piece of hardware fails. Provided the virtual machine images are on shared storage or have been replicated to another storage device, affected VM images can be restarted or even maintained on another hypervisor when their primary hypervisor host fails. This same concept can even apply to an entire datacenter worth of VM images in the event of a complete site failure.
To me, however, the “HA” this concept provides stands for Hardware Availability. If a hypervisor host, cluster, or site goes dark, new hardware is quickly provisioned and the images are restarted. But what if the issue resides within the VM image itself? All too often a problem with the application or with the operating system affects service availability, and moving the VM image to different hardware is only going to move the problem along with it. In these instances, the two choices you’re faced with are to troubleshoot the issue in place (affecting total recovery time) or to roll back an earlier version of the VM image (greatly diminishing the recovery point.) To provide complete High Availability for an application you need a way to maintain business services regardless of the failure mode.
Neverfail‘s Continuous Availability products work alongside existing hypervisor solutions to provide a complete high availability solution that meets the most stringent RTO and RPO requirements. For the tier-1 applications in your datacenter, those that directly affect your company’s ability to conduct business, you need a solution that can eliminate downtime no matter where the failure may occur. Don’t get caught trying to resolve application issues while business is standing still. Continuous Availability means keeping applications up and running. Period.
