Buying Storage? Some Research Quick Tips for a SAN Purchase

There was an article on the VMTN forums the other day. Someone was sitting in the same position I was almost a year ago. They were confronted with a task of being the sole person responsible for buying the shared storage for their vSphere implementation. Having a team tackle this is the best approach so everyone can be happy with the decision, but when you're on your own, it's a very daunting task. Your strapped spending 5 or more hours a day just reading websites, watching WebEx's, or on the phone listening to a vendor. Here's a few tips from what I learned in my experience to those out there that need a little help in making their decision.

1. How much storage do you need? It's a good baseline for talking to any storage vendor. 3TB vs 3PB makes a difference. Especially when some storage companies have different products geared towards your level of business.
2. How much storage will you need in the future? You might not think about it now, but you have to anticipate storage growth. Just how fast are you going to grow? Some vendors have 1 model of their product and they can add on to it. Some vendors will hit a TB or drive capacity on their models. Some might just try to sell you the next model up.
3. What kind of storage do you need? SSD, SAS, FC, SATA. Different types of drives for different types of performance. Better performance = more expensive. SSD is still new and hasn't found it's way into a lot of production arrays yet because of the cost. Most virtual infrastructures run on either Fiber Channel or SAS drives that run at 15K RPMs because of performance vs cost metric. SATA is your cheap storage. I won't deploy a production virtual infrastructure that demands responsiveness on SATA drives. Last thing I want are people telling me that performance has killed their adoption of virtualization. Not to mention you probably just wasted a good chunk of change on that array and I'm not sure if storage vendors have return policies like Wal-Mart.
4. Test for some baseline IOPS. Every vendor will ask what kind of IOPS you have, or better yet, "want us to come in and do some IOPS testing for you?". Use tools such as perfmon over a period of two weeks or so, look at the max levels of your physical boxes, and calculate the IOPS. Therefor, not worrying about having that awkward conversation of "thanks for doing those IOPS tests, but we're headed a different direction".
5. What level of availability do you want? I usually always insist on having dual controllers for high availability. Granted, these things hardly ever have problems, but if they do, I don't want to be down an entire business day because we didn't spend the $10k or $50k on a redundant controller.
6. Take a look at your current infrastructure. Do you have fiber channel (FC) already in place? You do? Sweet, maybe you should look into an FC array. No FC? It's cool, iSCSI and NFS are changing the game with IP based storage and tests have shown that performance is almost on par with FC. Oh yea, don't forget the newbie to the line-up, FCoE.
7. Options! Look at your options. Do you know how many different storage companies are out there? There's literally hundreds. What does that mean for you? They are all fighting for your business, you are the one who wins in this situation.
8. With so many options, how do I know where to look? The vSphere HCL dummy! But Kenny, Storage Vendor ABC isn't on the list and they were telling me it's vSphere ready? That's awful nice of them to tell you that, but until they are on the HCL, if you have any problems with vSphere when it comes to storage, tough luck. It costs storage vendors money to be put on the HCL, but it also proves that their array will work with vSphere and you won't hit any bumps along the way. I would only buy an array that is listed on the HCL for that reason alone. Also, don't forget to look at the protocol. Some arrays may only be HCL certified for FC while others for iSCSI, NFS, or FCoE
9. Networking. Do you have the ability to go 10Gb ethernet in the near future? might be something to note if the array you're thinking about purchasing is easily upgradable to 10GbE or is shipped with it.
10. Every vendor is going to have a little feature that makes them stand out from their competitor. Create some sort of matrix and weigh out the pros and cons. Don't let a storage vendor try to sell you on Thin Provisioning. Every array basically ships with that feature now and it can be done within vSphere, so don't let that be a decision factor. Every vendor has their own take on what is called "storage virtualization", just look past that and look at the type of technology being shown.
11. Can I get a demo? Always view the product before getting a quote. If you have a lot of money to spend, some vendors will put in a SAN at your datacenter to let you test. You can also take the other route by having someone give you a WebEx demo of the product. Don't forget to look at the interface for the array because that's going to be your gateway for administering that beast for the next few years.
12. Use twitter. Got a question about which way to go on a vendor? or perhaps you want to ask a vendor a question? Alot of companies have representatives use twitter as a means to talk to potential customers and interact with existing customers. You would be surprised to see how fast you can get a problem solved over twitter versus calling tech support. Ask questions to the community, people will listen. Granted, some answers will be biased, but you atleast get an answer.
13. Listen to product announcements and read some news articles. Did company ABC just land a huge client? Cool, well you know they will be around to support you for the next few years. Also, when a company launches a new product into their line-up, it may make the price drop on the arrays you were already looking at.
14. DON'T LISTEN TO FUD! Storage companies have gotten better about not calling out their competitors, but you still see it. Vendor A will say Brand X can't do this or a feature their competitor owns doesn't work the way you think. Hear what they say, but don't let it be an altering decision. It's called marketing. By making their product sound superior than their competitors it gives them an angle. In the end, you're going to have a product that sits in your datacenter and fills up with company data, all you have to do is choose how to get to that point.