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Chapter 10: Disaster Recovery > Introduction - Pg. 256

256 Chapter10·DisasterRecovery Introduction I was once in a class talking to a guy who was using a virtualization tool to run Windows inside of Windows. The idea of doing this intrigued me. I asked him about it and he explained that he did it for a couple reasons. The first was that he could back all of his important data up by dragging a handful of files to a removable drive. The second was that whenever he got a new computer, migrating to the new computer was as simple as installing his virtualization tool, and copying his virtual machine onto the new computer. He didn't have to reinstall anything. He didn't have to go through every directory looking for things that he might want. He didn't have to set up directories marked _OLD just in case he forgot something. Disaster recovery poses very similar issues to the ones he solved on a minor scale. It can be prohibitively expensive to maintain hardware of the proper configuration for each critical server in a data center. Just trying to keep backups current without having to shutdown services for the copy can be cumbersome. Happily by having machines virtualized, a number of benefits can be realized. This chapter will illustrate some of those benefits. Hopefully the reader will see the flexibility which comes from having servers that can be moved from hardware platform to hardware platform with minimal reconfiguration. Disaster Recovery in a Virtual Environment The nuances of disaster recovery can mean many things to many people. Fundamentally however, disaster recovery implies the ability to recover and restore an organization's IT infrastructure, reducing (or eliminating) the amount of time the organization experi- ences a business outage. Disaster recovery includes not only recovering from things like natural disasters that impact the entire datacenter, but also recovering from incidents that may impact a single system such as hardware failure, a security compromise, etc. In a virtual environment, the definition of disaster recovery is no different than in a traditional/physical environment.You still need to determine: What is the maximum downtime that can be tolerated? What is the maximum amount of data loss that can be tolerated? What is the classification of resources (critical, urgent, normal, nonessential, etc.) for restoration? What kind of recovery plan is required for various types of disasters?