Let me apologize upfront for starting the blog with a trick question. What does OpenStack have to do with the choice of storage? Yet I get this question all the time, hence the title. OpenStack is a cloud operating system, which means it provisions, configures, and orchestrates the infrastructure for efficient execution of the application workload. On top of that you get the elegance of OpenStack’s modular and open design, which provides tremendous flexibility to choose the infrastructure you want. However, OpenStack doesn’t answer the question of what storage to choose. The decision to choose an appropriate storage is tied to the Service Levels required by the application workload you are running, regardless of the cloud operating system in use.
The above picture explains how we map the two from an EMC-centric world. The matrix tracks the characteristics of an application workload to the characteristics of storage infrastructure. For example, if you are running an ERP workload you will likely choose VMAX for its high availability and low latency features, whereas if you are running App development lab or Exchange you will likely use VNX for its $/IOPS and $/GB features. You get the point. EMC has a very comprehensive ‘Product Positioning Guide’ that characterizes many common application workloads and recommends storage that would be a good fit. Check it out at the following site if interested http://www.emc.com/ppg/index.htm.
Now let us get back to OpenStack. If your storage is determined by the application workload, all you need is a good plugin for the storage to hook up to the OpenStack framework. EMC currently provides plugins for block, VNX and VMAX, so that the transition to OpenStack is easy and without additional investment. The picture below shows Fibre Channel and iSCSI for VNX and VMAX using SMI-S provider. For VNX we also have an iSCSI plugin that interfaces directly using CLI commands. ViPR has one universal plugin for EMC storage, which will extend to non EMC storage as well in the future.. You will be able to use plugins for all EMC products like Isilon, Scale IO, Extreme IO, etc. very soon. We have some interesting offering on Object, which I will cover in the next blog.
Hopefully this bit of advice helps you avoid the potential pitfall of choosing wrong storage, just because of the flexibility OpenStack offers. I have seen many customers do that; the consequences of that were expensive and time consuming. Choosing commodity storage, with a small 5% rate of failure, can throw your Service Levels and TCO off the roof. Don’t get me wrong – there is a place for all kinds of storage, including commodity. I am suggesting you to map the application workload to storage correctly, and then look for plugins to integrate to OpenStack. It will make your journey with OpenStack a lot smoother.