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.

Economy Crisis this year has encouraged users to consider the ISCSI SAN Vs FC SAN today. Data Storage growth will never stop unless the business is stop. In order to keep the environment growth, the IT architect will have to provide a cost effective solution in the finance critical timing like now.

Performance wise, we may know that the Equallogic ISCSI might not beat the huge SAN box which easily cost you double as your TCO on ISCSI. I would like to share my finding relevant on the features it bundle with Dell Equallogic. In FC SAN, we are able to achieve performance and functionality, which require always additional license cost and expensive infrastructure to support it. Today, ISCSI provide more flexibility in term of FC due to the common understanding we all have on the IP technology which we deal with it everyday.

In Equallogic ISCSI, you will entitle every features which bundle together with the storages you purchase.

• Snapshot Volume Manager
• Thin Provisioning
• Raid 5, Raid 50, Raid 10
• Auto Load Balancing
• Web Base Console
• DR Replication
• Storage Replication
• Volume Clone

The details of the available features is more than what I am stated here of course. Imagine if you own a FC SAN today, you may end up paying additional charges for every piece of licenses you require of the functionality. Beside this, virtualization and VMware is become a main player for every Data Center today. Same with Equallogic, it had also become a powerful competitor to compete with the major vendor like NetApps, EMC, HP, HDS, IBM and etc.

Whithout comparing the cost and performance, I am really impress with the simplify management provided by Equallogic. You will not require to be long waiting of the web console, and it is user friendly and easy to be managed. Compare to FC SAN, you will require certain level of skillsets and patient for administration which you may suffer from the slow loading from the console always. Additional to that, FC SAN will become slower when the number of spindle and workload is increase, but Equallogic has it advantage with every array will increase the processing power and throughput. Personal experience, I am only require less than 10 minutes to setup and configure my Equallogic Storage array, and able to start provisioning right after the configuration done. Is Really Fast!!

I run the performance test on my ESX 3.5 server to compare the I/O performance Vs FC SAN, I realize that the performance is acceptable with the amount of money we pay for it. Simply because you may not virtualize the servers which require the real I/O intensive performance. I am able to achieve approximately 140MB/s with FC SAN for read/write, with Equallogic, I manage to achieve 115MB/s as maximum throughput in my VM. Again, this may be impacted due to the software ISCSI initiator. ISCSI HBA will able to improve the performance with minimize the overhead on ESX host. For my test, I only manage to run with single array. If we have more array in the future, it will able to increase the disk performance and storage throughput. 10Gb Ethernet are also on the way to the market next year. Equallogic are also design for SRM solution which provide by VMware to simplify the DR solution. With this storage solution, we will no longer require a big network pipe for SAN storage replication as we did for the FC SAN previously.

Latest array PS 5500E are providing 48TB in RAW with SATA, which will be a good option for DR solution to provide cheaper hardware cost & better functionality. If I has been asked to reduce my CAPEX for SAN purchase, the only option I can think now is ISCSI as my option. Cisco 3750 is the recommended switches for DELL Equallogic, it is much more cheaper if we compare to the brocade FC SAN swithces.

Never the less, FC SAN are still the best option in term of reliable and performance, but as it is a tough time now for budget spending, I believe Equallogic has provide us an additional option with limited budget.