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In my last blog post I talked about what I see as the next "waves of virtualization" taking the industry, I talked about "IO Virtualization" as a key (maybe THE key) cornerstone, so I thought it might make sense to describe just what it is and why it's important. Like all forms of virtualization, the physical world is masked and abstracted into a virtual representation, allowing for higher utilization or increased agility, etc. For IO, the physical world is typically defined by dedicated connections to Input/Output (IO) devices such as disks, networks, cdroms, consoles, etc. In the enterprise, these devices can themselves be already virtualized (think Storage Area Networks) but their connectivity is typically very static – e.g. a fiber channel adapter connected to a specific port on a SAN switch. IO Virtualization abstracts the connectivity so the server itself is no longer statically configured to specific IO wiring. This adds tremendous value to the enterprise. The most obvious benefit is that change management becomes easy. No longer do techs have to fish wire and re-wire data centers because server-to-IO affinity has changed. With virtualization, the wiring stays static but the actual mapping between the server and the IO devices can be dynamic. And this is just the beginning. IO Virtualization also allows for easy server re-purposing, as a server can be “re-wired” to attached to different volumes on a SAN device or different networks, thus changing its personality or its life cycle (e.g. moving from test networks to production networks). IO Virtualization also enhances Server Virtualization, as it makes it easier for hypervisors to support migration – no need for clunky clustered file systems or open zoned SANs, which can expose serious security issues. Taken even further, IO Virtualization can help with Disaster Recovery. When the server is abstracted away from its IO connectivity, it becomes very simple to move a set of servers (and their applications) to a remote site and quickly re-create the IO environment. Something that can take weeks in the physical world can literally take minutes now. So, hopefully you can see why IO Virtualization is such a key cornerstone technology in the continued virtualization evolution. Be aware, though, that not all IO Virtualization is created equal. IO Virtualization is not done by adding new layers of unmanaged hardware into the mix (think NPIV) and IO Virtualization is not simply re-programming network and SAN switches as some would have you believe. It’s really about creating an agile abstraction layer that truly disassociates servers with their IO devices, allowing for total flexibility in the data center.