-by Michael J. Callahan

Since this is my first posting here, I thought I should introduce myself. I am the Chief Technologist for the HP StorageWorks Scalable NAS Division. HP is very serious about broadening its offerings in file-based storage, and the creation of this division was a reflection of that. A significant part of the division--though by no means all of it--came to HP through the acquisition about a year ago of PolyServe, a shared data clustering software company where I was CTO and cofounder. HP had long partnered with PolyServe to deliver NAS solutions using HP servers and storage and PolyServe software, so it was natural for us to find a home here.

It's been a tremendously exciting first year: being part of HP has allowed us to deepen our investment in PolyServe's clustering technology dramatically and also to leverage HP's great strengths in servers, blades, storage hardware, and storage and management software. Last week we announced some of the first fruits of the work we've been doing--the HP StorageWorks 9100 Extreme Data System--and so for my first post I'd like to discuss why I'm so excited about this product.

The ExDS solution builds on PolyServe's experience working with customers who are building new business models based on having vast amounts of data, from hundreds of terabytes to multiple petabytes, available on-line at low cost; for example, web digital media and social networking services, and some kinds of scientific and technical applications.

It's worth acknowledging up front that this isn't everyone. We have customers using our software in a wide variety of ways, from financial institutions running mission-critical applications handling millions of transactions a day, through enterprises building scalable, easily-managed NAS services out of industry-standard servers and consolidating their Microsoft SQL Server databases into highly-available, efficient clusters. For these customers, integration with traditional data center storage infrastructure, like our MSA, EVA and XP storage arrays, is key. We've covered those needs for the past few years with several offerings: the HP StorageWorks Enterprise File Services Clustered Gateway, which includes everything you need to build scalable, highly-available file services on top of traditional enterprise storage; the HP StorageWorks EVA-FS, which adds EVA storage to the EFS-CG; and finally various software-only options, where you add your own servers and storage. ExDS is not a replacement for these products.

In our experience, however, petabyte-scale deployments have a distinct set of requirements, and that's what ExDS is designed to address. Typically, we've found that customers in this space are very concerned about issues of cost, physical density, power efficiency, and manageability/operational efficiency:

- If you're buying such large amounts of storage, obviously cost per gigabyte becomes a major concern. One way of looking at this is: what solution delivers the thousands of drives you'll need for petabytes of data with as little cost overhead per drive as possible?

- Besides cost efficiency, customers are looking for solutions that are physically dense and power-efficient, to make economical use of data center space, power and cooling. Again, you can view this as asking, per drive, how much physical space and power overhead does the system impose?

- Whereas in enterprise environments, it's typical to have storage administrators' responsibilities measured in tens or hundreds of terabytes, in petabyte-scale deployments this would clearly be uneconomical. It must be possible for an individual administrator to handle petabytes of storage.

The ExDS contains a lot of new engineering to provide a complete solution addressing these concerns, building on our experience working with customers who have constructed petabyte-scale environments using PolyServe software. These customers have typically combined PolyServe software with storage hardware of their own choice, in many cases making a significant investment in custom integration to put the whole solution together.

To achieve excellent cost-, space- and power-efficiency, ExDS is based on HP c-Class BladeSystem blades and new storage hardware, different from anything in the existing StorageWorks product portfolio, which we're calling 'storage blocks'.

- Blades run storage services for the outside world, and an ExDS can be configured with anywhere from 4 to 16 blades, based on the level of application performance required.

- Storage blocks contain disks in a very space- and power-efficient package. Each block consists of 82 drives in 7 rack units of space, for a density of nearly 12 terabytes/U with the 1TB drives we'll have. An ExDS can contain from 3 to 10 storage blocks, for up to a total of 820 drives.

Note that performance and footprint can be scaled independently--it's perfectly legitimate to have an ExDS system with 4 blades and 10 storage blocks, or 16 blades and 3 storage blocks. This in itself can be a major source of savings, since you don't have to pay for (and power, and cool) CPUs you don't need.

To address the operational issues entailed by operating at such a large scale, ExDS contains new appliance management software that permits the entire system to be provisioned, configured, monitored and optimized from a single console. Blades and storage blocks can easily be added to an ExDS system using the console, and any failures (drives in particular, in a system of this scale, are bound to fail) are surfaced to the administrator with direct information about what FRU to replace to solve the problem.

Of course, ExDS also includes the PolyServe software, which includes a cluster file system allowing all blades to access all storage in the system simultaneously, provides complete high-availability, and allows standard software--even the customer's own application--to run on the blades within the ExDS system .

I have a lot more to say about all of these elements in future posts, but for now let me just close by saying again how pleased I am to be able to start talking, finally, about some of what we've been working on. From a PolyServe perspective, ExDS does a great job providing a complete, simple, out-of-the-box solution to a big challenge--whereas, in the past, we've seen customers have to invest a significant effort to build similar environments themselves. It also shows why being a part of HP is such an advantage. I mentioned above that the StorageWorks Scalable NAS division, although it includes PolyServe, is far more than just PolyServe. In fact, the ExDS solution has been built principally by a part of our team that was not formerly from PolyServe, and it includes a lot of work, and indeed IP, from other parts of HP. I think it's a great start, and I expect to have a lot more to say about it, and other things we're doing, in future.

I'd love to hear your feedback on ExDS or other aspects of our technology!

Michael J. Callahan

SWD NAS Division CT