Virtualization is quickly being adopted in many different industries. As virtual machines move from testing and development roles into production, security becomes ever more important. Virtual servers are no less secure than regular servers, and may provide additional security by compartmentalizing applications.
However, when companies deploy virtual servers in production, they change their operational practices to take advantage of the flexibility of virtualization. Servers are pooled together, provisioned and deployed automatically from a handful of standardized operating system images and moved around dynamically in response to changes in demand or maintenance needs. These operational practices require a new approach to security.
In a research benchmark conducted in the first quarter of 2007, I asked IT executives how they treat virtual servers from a security perspective. Although the majority of participants are not yet running production systems on virtual servers, many say they plan to do so. When asked how they secure their virtual servers, participants say they treat them like physical servers with respect to security, having the same kinds of agents running on the virtual hosts as on the physical ones, and using virtual LANs (VLAN) to segment virtual servers within the data centre. To exploit virtualization to its fullest and become vastly more agile in response to changing business requirements and opportunities, IT will need to do considerably more than treat virtual servers like really thin, densely stackable physical servers.
Corporate security teams will have to embrace security tools that can fully cope with servers that move from place to place within a data centre or among data centres, that can change media access control and IP addresses along the way, and that may exist for only a few minutes at a time if they are being created in response to changing workloads. And while VLANs are a good short-gap measure, from a management perspective they can quickly turn into VLAN-spaghetti in a dynamic environment.
Virtual servers can be treated just like thin, densely stacked servers. But that misses the point. Virtualization frees the server from its physical “body” and gives it flexibility and portability. To take advantage of these traits, we have to adopt security measures that also are dynamic and flexible. Otherwise, we are hobbling our virtualization strategy because of inadequate security.