VMware

July 21, 2008

VMware's "Proprietary" Clustered File System

There has been some discussion lately from some of our competitors on their storage architectures or lack there of. Their boast is that VMware has a “proprietary clustered file system” that forces you to change your storage management practices while they preserve your physical storage management. They’re right, they do completely preserve the complexity of physical storage management. What they fail to mention is that this is a problem, not a solution. Physical SAN management is overly complex and a headache for most customers. And in the virtual world, the status quo is compounded! Instead of managing dedicated LUNs for every physical server, if you buy their argument you’ll be managing separate dedicated LUNs for every virtual machine! 

VMware doesn’t have a vested interested in preserving physical complexity. That’s why VMware invented VMFS and our hypervisor-based storage stack. Virtualization is all about abstracting the physical world to ease management burdens and reduce complexity. VMFS is very special purpose clustered file system that is largely transparent to our customers. It is used by VMware’s ESX Hypervisor to abstract and share LUNs used to store Virtual Machines and their Virtual Disks. 

The result? Great customer benefits, such as:

  1. VMware’s instant one click provisioning, including storage. Quick, easy provisioning of a new VM, OS and application that does not require physical storage LUN provisioning.
  2. Mobility/Portability. i.e Vmotion and storage Vmotion. In a virtual world, workloads should be abstracted from, not beholden to, physical storage. Just like they should be abstracted from physical servers.
  3. Encapsulation and HW Independence. VMs should be entirely encapsulated from the physical world. This simple, but critically important facet of virtualization unleashes the power of virtual infrastructure. For an example, look at VMware’s new Site Recovery Manager that enables DR solutions that no longer require identical hardware (and software) configurations at each site.
  4. Reduced complexity. SAN management is hard, complicated work. Why shouldn’t it be simplified?

Now is VMFS good for absolutely every use case? No, sometimes it’s important to preserve a physical LUN format for a given workload. That’s why VMware supports RDMs (Raw Disk Maps) which allows a customer to directly map an entire LUN into the guest OS while still maintaining virtual infrastructure benefits. The trade off with RDMs is more LUNs to provision and manage, but direct access from the VM to a native physical LUN.

What our competitors fail to mention is that not only does VMware support all the use cases they claim to provide, but we also bring all the benefits of virtualization to the entire data center, storage included. And that’s something worth touting!

Welcome

Welcome to the VMware Storage Blog, a blog dedicated to all aspects of storage in the virtual environment.
We get a lot of questions about Storage Architecture in VMware Virtual Infrastructure. It is a complex topic with many options and design trade-offs to consider. In this blog we will attempt to demystify the topic. Please let us know how we are doing! Thanks.