The endless variety of enterprise storage solutions means that you can find pretty much exactly what you need -- if you have your requirements straight. The trick to avoiding overspending or under-specification is knowing what questions to ask when you're deciding which option is right for you. Here are three questions I seldom see asked or answered with enough care or thought:
1. What is the expected lifetime of the solution I am designing?
If you want to prevent your budget from being shattered by unexpected expenses a few years down the road, give very serious thought to how long you want your storage solution to last. Sudden cost increases in the out years usually stem from unplanned capacity growth and unexpected late-year support costs. Define the period of time that your solution is likely to be used, and you reduce the risk of either eventuality.
In the data explosion, it's always tricky to assess your future storage without low-balling it or simply coming up with a fantastically large number. Giving yourself an accurate estimate will require lots of information about your storage needs over the past year or two, both the rate of capacity- and performance-load increases. Keeping future storage-intensive initiatives in mind, such as that pie-in-the-sky paperless office everybody keeps talking about, is important too. Either way, you can't make useful forward-looking estimates without knowing the period of time that you're planning for.