Virtualization Technology News and Information
Don't lose your integrity! Preserving data in virtualized infrastructures during power outages

A Contributed Article by: Hervé Tardy, Vice President and General Manager, Distributed Power Quality - Americas, Eaton Corporation

Keeping critical workloads operational is a data center's top priority during a power outage. However, it's the inconvenient truth that servers must sometimes be shut down in order to prevent data corruption. Traditional data centers have long relied on a combination of UPSs and power protection software to shut down servers during utility outages, but server virtualization adds a degree of complication to defending data during power failures. Live migration capabilities can move VMs dynamically from one host server to another under a variety of conditions, but few such products offer built-in functionality for migrating virtual workloads automatically during outages, when the function is most often needed.

The good news is, technology continues to evolve to solve such issues, and newly developed power management solutions have the ability to significantly reduce the risk of data loss. By automatically "showing up" to shut down servers in an orderly fashion when disaster strikes, the latest solutions are essentially a knight in shining armor protecting a virtualization environment's data.

First, let's take a closer look at the challenge... when a virtualized data center loses power, technicians must shut down not only their physical servers but also the virtual machines running on those servers. They must also execute the many steps of that process in a specific sequence, often in the face of stress and pressure. Virtual machines must be shut down before physical ones, and core devices (such as domain controllers and shared storage arrays), after the servers that depend on them.

There are three innovative ways to overcome these challenges:

1. Download open source management code

Websites such as Network UPS Tools ( have developed pre-written, open source operating system codes that can shut down servers gracefully and in the correct sequence during power failures. By downloading, installing and customizing such code, data center managers can shut down servers in the proper order when utility/server power becomes unavailable. This solution offers an easy yet extremely powerful and highly configurable power management option to organizations that use and customize Linux or other open source solutions, a category that includes most operators of cloud computing data centers.

2. Deploy advanced power protection and management software

While power protection applications enable organizations to shut down servers in an orderly manner during utility failures, most systems only support physical devices. The latest and most sophisticated power protection solutions, however, support virtual machines in addition to hosts such as VMware ESX, Microsoft Hyper-V, Citrix XenServer and Red Hat KVM. This technology, when added to a virtualization management system, can shut down both physical and virtual servers in pre-defined sequences to minimize vulnerability to data loss.

Eaton's software automatically moves virtual machines from host servers impacted by an electrical outage to unaffected servers elsewhere within the server cluster to preserve data integrity. Furthermore, when integrated with VMware's Site Recovery Manager, Intelligent Power Manager software will initiate planned migration moving server workloads from the protected site to a recovery site hosted in a cloud environment.

When a virtualized data center loses power, and there is no recovery site to move the workloads to, Eaton's Intelligent Power Manager software will provide a graceful shutdown of any or all servers and virtual machines running on them to minimize exposure to data loss. Intelligent Power Manager's tight integration with Citrix and VMware allows for graceful server shutdown, remotely, without the need for any shutdown agent to be installed on either a host server or virtual machine. 

3. Add automated scripts to advanced power protection software

Many advanced power protection solutions enable users to create scripts that automatically respond to specific alarms in a predefined manner. Companies can use such scripts to augment their power protection system's built-in functionality. For example, technicians could extend UPS battery runtime by creating a script that automatically shuts down virtual machines running non-critical workloads early in a power outage and then consolidates the remaining virtual machines onto a smaller number of host servers.

The rate of innovation is amazing. Within the span of a few years, server virtualization has progressed from a promising new technology to data center mainstay. Although there have been challenges along the way, virtualization-supporting software developments have armed IT and facilities managers with potent new tools to maintain uptime and preserve critical data. By harnessing the power of the latest power management solutions, users can now take full advantage of server virtualization's rewards while mitigating its risks, preserving the integrity of two very important things; their business and their data.

For more information about Eaton's solutions for virtualized environments, visit To learn more about Eaton's power quality products, visit


About the Author

Hervé Tardy joined Eaton in November 2007 as Vice President and General Manager of their Distributed Power Solutions business unit, with responsibility over single-phase UPSs, software and connectivity products. His responsibility has recently been expanded to include the management of marketing and sales initiatives through the fast growing IT channel in the Americas. Tardy is based in Raleigh, North Carolina.

Published Thursday, July 05, 2012 7:00 AM by David Marshall
Don’t lose your integrity! Preserving data in virtualized infrastructures during power outages « VT News - (Author's Link) - July 5, 2012 7:29 AM
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