For blade environments, there may soon be a middle ground between blade servers with disk drives on them and network...
storage: functionally and physically integrated storage blades.
Case in point, blade server vendor Verari Systems, formerly known as RackSaver, last month announced that it would resell SAN storage from Engenio, formerly LSI Logic. Today, the extent of the integration between Engenio arrays and Verari's Blade Rack is connectivity: Blade Rack can be outfitted with a Fibre Channel switch, the blades themselves with HBAs or you can buy a "NAS head" blade. But there's more in store: "We're stepping to the OEM level, and working on tight coupling of the bladed product with their storage," says Verari CEO Dave Driggers. Eventually, that may lead to storage blades that fit directly in the chassis, for "a floor-tile ready integration."
Storage blades make sense for certain applications, says Taneja Group president Arun Taneja, namely, I/O intensive applications that aren't too capacity hungry. Storage blades could also encourage diskless booting. "First-generation server blades all had a couple of drives on them to boot from," he says, but "there's no question in my mind that drives are going to be isolated and completely independent of the blades."
Today, about 90% of Verari blades ship with an onboard disk drive, but "as storage becomes tighter coupled with the blade, we expect more customers to boot directly from that storage."
Hewlett-Packard, another big blade server vendor, isn't ready to announce any specifics, but a spokesperson did say that "HP is currently working on many fronts to leverage our ProLiant blade and StorageWorks SAN market leadership, by pursuing extensive integration at all levels to help customers realize the greater value, simplicity and agility blades and network storage can deliver."
A storage blade can only go so far, though, says Rob Peglar, CTO at SAN vendor Xiotech: "At the low end of the scale, storage modules would work, but if you're trying to collapse hundreds of servers, the network storage approach is better."