C
ChUIMonster
Guest
From a db performance point of view putting flash in a shared storage device is putting it in the least useful place that it can go. That's a great way to drain you wallet and get poor performance while financing a new yacht for the Netapp sales team. Just say no. If you want your IO subsystem to be fast: 1) Do not put it at the other end of a cable. 2) Do not share it with other applications. Instead spend a small fraction of the same money on internal SSD and get great performance. If your storage & admin team complains that their life is somehow made more difficult take a portion of your savings and hire some new storage & admin people. You will still come out ahead. Database IO is random IO. Somewhat perversely, the better tuned your database is, the more random your IO becomes. The latency of each and every IO operation is your enemy. In a SAN (or NAS) the main contributor to latency is the cable along with the various adapter cards along the way. Not the device holding the data way out at the wrong end of that cable. "Oh but it's a zigabit per second cable!" shows that whoever says such a thing has totally missed the point. Zigabits per second is a useful metric for sequentially streaming data -- it says *nothing* about the latency of random access. From a database centric performance perspective internal SSD is: 1) Faster. *Much* faster. Literally 100x faster. 2) Cheaper. *Much* cheaper. You can buy enough SSD for most databases for the price of a good steak dinner. It really isn't even close. But people will still insist on poking themselves in the eye with sharp sticks rather than doing the sensible thing. Because, after all, if it is the right solution for file sharing then it must be even better for a database application.
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