EMC talked as much, if not more, about what its Storage Router won't be as what it will be, at its analyst day in New York recently.
Defining the product by what it's not, analysts say, is a tactic the company is using to try to spoil IBM's lead with SAN Volume Controller, its virtualization appliance that began shipping in May. And second, they say EMC is still deciding on exactly what it wants the Storage Router to be.
"Given that it probably won't ship for another year, EMC is giving itself plenty of room to adjust and modify its position," said John Webster, founder of research firm Data Mobility Group. EMC said the product will enter beta testing in the third quarter of this year and will ship in the first half of 2005.
Consequently, getting the company to be clear about what storage applications the router will perform versus what will remain part of the array wasn't easy. It's a 'here AND there' proposition, not a 'here OR there' proposition," said a company spokesman.
Here and where?
For example, the spokeperson said the highest levels of replication for disaster recovery, business continuity and data preservation, will always be array-based. "There's simply no network- or host-based replacement for that level of performance and availability."
However, he added that network-based replication technology provided by products like Storage Router will be used to more cost-effectively extend replication across more of the storage infrastructure. An example of this might be replicating non-critical data to lower service-level storage tiers for backup staging or application testing.
"And again, certain volume management tasks will be handled at the host level and others in the network for non-disruptive movement of data," the spokesman said.
Arun Taneja, Founder of the Taneja Group pointed out that virtualization is supposed to make a storage administrators life more simple. "One thing you don't want to do with virtualiztion is make it more complex," he said.
Mark Lewis, executive vice president and co-lead of the newly formed Software Business Group at EMC, said there will be three components to the Storage Router: an intelligent switch, an appliance that runs the software and the software.
EMC is working with Brocade Communications Systems Inc., Cisco Systems Inc. and McData Corp. for the switch. And each of these companies is expected to ship its product before EMC's router hits the shelves. "Our delivery of a solution will take it to a different level," Lewis noted.
More specifically, he said the Storage Router won't be an in-band appliance like the IBM offering. "These devices are limited function RAID controllers trying to be a virtualization appliance. They will cause significant performance problems down the line," he said.
Lewis is refering to the old argument that an in-band appliance which sits in the data path processing the I/Os, will eventually cause a bottleneck on the network. However, with out-of-band appliances, like EMC's slideware Storage Router commands go directly from server to storage and back, in theory making throughput faster because the network is not burdened with any decision making. The control information about the data – when it was created, what it's for, and so on – resides on the appliance and can be updated when necessary. Unlike in-band systems, this control data does not have to travel with the actual data across the network each time it is accessed.
Switch maker, MaXXan Systems Inc., says the in-band versus out-of-band argument is a moot point these days -- its switch is architected to do both. "There are applications and environments where one is more suitable than the other. There is no reason for vendors to claim that one is consistently superior to the other," a MaXXan spokesman said.
Webster added that EMC appears to be putting the cart before the horse where its marketing is concerned. "They first of all have to prove their technology before they talk about performance … Out-of-band virtualization is complex, and people have been trying to make this technology work for years," he said.
He noted that IBM isn't idly sitting around waiting for EMC to come out with a better performing product either. IBM might have gone quiet on Storage Tank, the company's code name for its out-of-band virtualization offering, but that doesn't mean they've given up on it, Webster said.
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