EMC Says Virtualization Is No Threat to Hardware Sales
By Tim Stammers
August 7, 2001
EMC Corp says its decision to develop virtualization software is not, as described by one analyst, a "big risk, but a way for it to consolidate its software leadership. The company's CTO Jim Rothnie yesterday laid out EMCs plans to ComputerWire, and said it has opted for an out-of-band architecture for its virtualization technology, in order to avoid the risk of a data bottleneck.
The software will be part of an initiative that EMC has dubbed Automatic Information Storage that will also deliver dynamic load balancing or redistribution of data across networks. According to EMC, what it plans to deliver is not virtualization, but "data abstraction" and automation. That
stance may just be associated with a widespread industry view that virtualization, which is set to be a mainstream technology within the next couple of years, will commoditize storage hardware. As a result, it threatens
to erode EMC's enormous market share at the top end of the market.
But according to Rothnie, there is no danger for EMC. "The reasons for buying [high-end EMC] Symmetrix storage are as true for a virtualized system as for a non-virtualized system. Customers are buying it for its performance, its
reliability, and its ability to move data rapidly. None of these things are changed," he said.
Steve Duplessie, an analyst at Milford, Massachusetts-based researcher the Storage Enterprise Group Inc does not agree. When 80% of their revenues come from boxes, it's a big risk. The goal for them is to have their cake and eat it - to be an open systems supplier and still sell huge amounts of hardware, he said.
But if anyone can have their cake and eat it, EMC can according to Duplessie. "You can question EMC's products, or even their strategy. But you can't question their ability to execute when they decide to do something," he said. EMC was founded on the belief that the route to success is "to execute even mediocre plans violently," he said.
The AutoIS plan has three technology legs, which will be delivered over the next 12 months. The first is "data mobility", or the automatic redistribution of data across networks from array to array. This will be completed with an update to EMC's current SRDF remote mirroring software. This will extend the ability of EMC's Symmetrix Optimizer software, which currently attempts to maximize performance by automatically shifting data from disk to disk within an
array, but not from box to box. "Data mobility will obviously be useful for performance tuning, but it will also be very valuable for automatic configuration changes, or capacity expansion. All you'll need to do is plug a
box into the network and wait for the system to integrate it," Rothnie said.
The second leg involves I/O redirection, or the repointing of application servers to new locations for data after it has been moved. EMC will achieve this by modifying its PowerPath load balancing system, which manages I/O
channel redirection. Tying in with an overall message that EMC is not following the market into virtualization but is instead building on its strong software position, Rothnie described the the three-year old PowerPath system as
ubiquitous, and said it has sold 25,000 copies.
The final leg will be the heart of the system - a traffic monitor that will decide when data needs to be moved and where to, in order to optimize performance or resilience. This software will be based on EMC's ControlCenter system, and will run on a general purpose server, or appliance. This device will be out-of-band - storage traffic will not flow through it. This separates EMC from virtualization suppliers such as StorageApps Inc, whose acquisition by
Hewlett-Packard Co was announced last week. StorageApps system involves appliances through which storage traffic passes - an in-band system.
"You may have 100Mbps of throughput, and you just don't want that passing through a single machine, like in the StorageApps system. It's clear right on the surface-that's risking a bottleneck," Rothnie said. If multiple in-band appliances are used, the bottleneck may be averted, but the logical pool is split into several parts, compromising the virtualization, Rothnie added. Unlike other distributed intelligence virtualization systems, EMC's software will not require agents running on SAN HBAs, or on switches, he said.
Duplessie commended EMC's distributed approach as "ballsy" and said it is the ideal solution which has only been attempted by one of the current virtualization start-ups, StorAge. But the bottleneck threatened by in-band
solutions is only theoretical. "We don't have enough empirical data from customers to know yet. In theory, there could be a bottleneck - but we just don't know at the moment," he said. "In the perfect world there would be an
out-of-band solution that also has an element of control on the switch. I think ultimately that's where we'll go," he said.
Rothnie claimed that the only reason bottlenecks haven't yet been seen in StorageApps inmplementations is because that company's system has yet to be deployed in large installations. A StorageApps spokesperson however said the
company's largest installation manages over 1000 storage devices. StorageApps uses multiple applicances to run its SanLink software in large installations, and the spokesperson said that presents no problems splitting virtualized pools into sub-pools. Data can be moved from the control of one appliance to the next, he said.
tim.stammers@computerwire.com |
