Plug And Play? No Way
Integrated database systems typically require many hours of configuration. "Our target is three days to get up and running," says EMC's Lonergan. IBM's target for its Netezza appliance is 48 hours. Oracle offers similar estimates--one day to set up the Exadata hardware and another day or two to get its software running. However, we've talked with customers that took weeks to tune and tweak the database for peak performance.
Even three days may seem like an eternity to IT teams accustomed to the instant gratification of other classes of appliance, but it's a vast improvement compared with the process of building out conventional database deployments from scratch, a process that can easily take weeks or months.
Physically, database appliances also aren't the simple devices that the name implies. Most VPN or WAN optimization appliances are self-contained boxes that occupy at most a few rack units and perhaps give IT the option of upgrading a switch port or hard drive. In contrast, data warehouse "appliances" may comprise 100 or more separate boxes occupying 10 racks and strung together using high-speed Ethernet or InfiniBand. Most start at a minimum size of one-quarter rack, generally including servers configured either for computing or as storage nodes (at least one of each) and a switch to link them. For example, the Oracle Exadata X2-2 quarter-rack system uses four storage servers and two compute servers to create a system with 96 TB of raw disk capacity and 48 CPU cores.
This is a far cry from one main benefit of pervasive virtualization--namely, consolidating servers and using less physical space in the data center.
The great compensating benefit of this design, however, is scalability: IT can start with a quarter-rack system and plug in new storage or server nodes--or entire racks--as necessary. Again, being able to add on in such a piecemeal fashion is a deviation from what we usually think of as an appliance, but the intention is that each upgrade will be at least as easy as the initial installation. Because of that, some integrated system vendors argue about whether their products should even be called appliances. Phil Francisco, VP of product management at IBM Netezza, says the term is apt. Oracle's Shetler says the company doesn't call Exadata an appliance "because that suggests something that's relatively small or that requires minimal administrative support."