Hypervisor Storage Integration - Is Citrix leading the Game?

Had posted in my previous post on the feature comparison between XenServer and ESX.

Apart from those, storage integration has been one area where Citrix has been leading the game. XenServer 5.0 has built in integration with NetApp and EqualLogic storage arrays. This enables XenServer to leverage the storage features like Snapshotting, Fast clone and thin provisioning.

Though this might not have a serious performance implications for normal workloads, this integration makes XenServer more suitable for disk intensive workloads and for apps like VDI and LabManager. Both VDI and Labmanager rely extensively on the fast clone and snapshot features. Offloading these functions to the storage should give users noticeable I/O performance enhancements and also free up CPU cycles on the Server. I am not aware of XenApp using the fast clone technology like VMWare View Manager does, but Citrix Labmanager (OEMd from VMLogix) extensively uses this feature and should be interesting to note the performance differences between VMLogix Labmanager on ESX and on XenServer with NetApp storage.

Citrix has gone another step further by introducing the new product - Virtual Storage Manager (VSM) for both XenServer and Hyper-V. This product integrates with the leading storage vendors and provides the capabilities to carve out LUNs on the arrays on demand and present them to the hypervisors. This should fill the gap with the non-availability of Cluster file system in Hyper-V. Being a 1.0 product, it seems to lack functionalities in terms of the no. of storage vendors it supports and also support for Zoning of the FC switches. But this definitely is an interesting product to watch out for.

In my view VSM should boost the virtualization of I/O intensive production apps. By mapping storage LUNs straight to the VMs, you can provide the same performance and reliability to the VMs as that of physical machines. By automating and integrating storage provisioning with the hypervisor tools, Citrix has given the flexibility to quickly provision the VMs On Demand.

VMWare is definitely not lagging far behind. VMWare has announced the vStorage framework for integrating drivers and features specific to storage vendors into ESX 4.0. Should be interesting to watch if VMWare can come out with a broader vendor support and more features compared to Citrix in vStorage.

Let's wait and watch.