There had been numbers of review and discussion regarding the choices of storage for us to run on Virtual Environment today. I believed that the hot discussion is always moving talk about the right storage with right design and implementation to the VM farm always. The most hottest topic are still regarding the NFS, ISCSI and FC implementation which provide better features, performance and reliability.

Personally, I had 3 of it running in my environment now and of course, I had spent a huge number of times to really test out all the solution and compare apple to apple to further study of my requirement. Here are some reading I get from my test for 3 solution above.

For I/O performance, I am using the IO meter as to generate the max output to the storage. I manage to get 190MB/s for my FC storage on 100 % read, and I only managed to get the output of 170MB/s on ISCSI, but on NFS, I only managed to get at 125MB/s. If we look at the number here, and compare to my high load R900 ESX host, actually it is more than enough to handle the number of VM I have in the ESX host. There are a lot of article introduce NFS, and the features of Netapps, but remember, ESX itself had improved from time to time. Thin Provisioning is no longer new thing, as you may get it with many vendor today by free as well as volume snap. But Dedupe will still be an interesting technology in netapps. If we look at FC, you will mostly lose all this technology, but it provide a stable performance as you need to virtualize some heavy environment moving forward. I am currently still test out the storage solution before I decide to go with a final choice. I will suggest to keep an eye on the technology trend as we may also remember that the VMware ESX 4 is on the way, which may change the game of storage strategy significantly.

Storage is always the important piece to be run in Data center as well as any solutions we put into the production environment. It will also impact the capacity planning, performance as well as the sustainable period of the specify solution.

Here I would like to specify talk about ESX storage planning. As many of the cases I read and experience before, more and more users are really heading to the stage of choosing specify storage for specify solutions. Example you may think off for using Netapps on NFS for ESX, which claim better performance, dedupe and protocol different. Somehow, the users had forgotten that they had not run any of netapps storage in their existing environment. When we look at the management perspective, the operation management for IT support is not SIMPLIFY. Everyone know how important to standardize our environment as well as simplify out IT environment. The more complex you have, the more pain you will feel.

ESX had been design to run on multiple different range, different brand, as well as different type of protocol of storage in the market today. The reason of this is able to provide users a number of choices to be choose for deployment which may really fit the existing environment. Most users are now been looking at the storage specifically for Virtualization, that was really due to the marketing strategy or brochure been always claim the specify products will gain better performance. If you are the storage guys in your IT department, maybe you should consider what will be the best fit for your environment VS what is the coolest technology in the world for VMware.

Let talk about 1 scenario here, a user who had existing running with cx3-80 EMC SAN storage with all fiber switches ready. The storage is only 50% populated. The storage guys had raised the request to bring in the latest ISCSI technology from netapps and Equal logic. When it does the price comparison, the TCO and implementation cost of ISCSI become too huge different VS extending the enclosure on cx3-80. Back to real world, I am really curious that if SAN Fiber storage will be poor perform and inconsistent compare to ISCSI if you have everything setup and configure correctly in your fiber SAN. Most of the case is NO. As in my POC test, I can see that the performances on the Fiber are still better and stable.

ISCSI is really simple and easier manage, but somehow, there are many technical details that require redeploying the entire environment to gain the peak performance you expected. That is definitely an advice at the end you will get from the vendor. Therefore, a best fit storage for your own environment is more important always. You should look at CAPEX vs OPEX when you plan the storage for virtualization.