I’ve been tasked recently on a project to increase availability of applications through the use of multiple/disparate storage systems. This environment has heavily invested in EMC Clariion and Celerra storage systems over the past few years and needed a non-EMC platform from which to build the second half of a redundant storage environment. For various reasons I won’t go into here, we chose IBM nSeries as that second platform. (Since the IBM system is rebranded NetApp FAS, I will refer to this as a NetApp filer.) I’ve been working on implementing the new equipment as well as integrating it into the Business Continuity strategy.
The overall strategy is to continue to use the EMC Clariion/Celerra systems for production and disaster recovery replication and split applications between and across the two storage platforms for local redundancy. The NetApp will also perform disaster recovery replication for some of the applications. Here’s a really simple diagram that might help if the description is confusing:
Now this may sound easy, but it is, in fact, NOT straightforward. This strategy requires close coordination with application owners and careful planning. As we move forward on this project, I’ll talk about various idiosyncrasies, caveats, and problems we’ve faced, how we got around them, and I’ll also talk a lot about the differences between the Clariion/Celerra and NetApp platforms’ features and functionality, application support, and manageability. These comparisons will include using both systems with FiberChannel connections as well as CIFS/NFS NAS, all in conjunction with DR replication and failover.
To start off, I figure we should compare some of the terminology between EMC and NetApp systems. Some terms don’t directly translate, but I matched them up as close as I could and noted where there is no equivalent. Below are two tables: one for Block Storage, and the other for NAS Storage. Click on them to see full size versions.
In the next update, I’ll start talking about the deployment itself. The point of these articles is to discuss the differences, advantages, and disadvantages of each platform so that you can understand how each one might work in your environment. I do not intend to disparage either platform or vendor. I will try to be vendor agnostic as much as possible, and I do feel like I have a somewhat unique position of comparing new and recent hardware and firmware from both vendors, in the same production capacities, simultaneously, in the same environment. I am NOT comparing old ONTap code to new FLARE/DART code or vise-versa, nor am I comparing old Clariion CX hardware to new NetApp/IBM hardware, etc.