If you think the requirements for enterprise storage systems are growing at a dizzying pace, try these numbers on for size: 25 petabytes of storage in more than 36 cabinets with more than 17,000 disks capable of delivering greater than 1 terabyte-per-second of I/O bandwidth performance to more than 25,000 compute nodes.
These are the specifications for the Blue Waters supercomputer and Lustre-based parallel storage systems project at the University of Illinois’ National Center for Supercomputing Applications (NCSA). The massively scalable parallel storage system is designed and being delivered by Cray Inc.
Scalable parallel file systems aren’t easy to build. The leaders at NCSA turned to Cray to build the system and come up with an integrated and modular storage solution to meet the staggering requirements of what is one of the most powerful supercomputers in the world.
The HPC storage solution has been deployed in a rapid time frame and at an unprecedented scale. The Blue Waters system will enable scientists all around the U.S. to conduct research with sustained performance they have never been able to achieve before. The research will potentially lead to breakthroughs in areas such as AIDS research, severe weather prediction and many other areas of science that could improve the quality of life all across the planet.
Beyond that, the work done by Cray and the NCSA team to create a new paradigm in storage will eventually impact commercial companies, the technical enterprise and other HPC and big data storage solutions, creating innovations that will enable faster, more effective, consolidated, more scalable and higher capacity storage systems. These will pave the way for far more powerful and effective HPC computing deployments (on- and off-premise) and data centers capable of delivering unparalleled levels of business and IT agility.
Breakthrough in Sciences
Blue Waters is a $208 million project of the National Science Foundation. The goal of the project has been to deliver a supercomputer capable of delivering sustained performance of 1 petaflop for a range of real-world scientific and engineering applications. The sustained petascale computing enabled by Blue Waters is available on only a very few supercomputers in the world, and Blue Waters is the only system of this scale provided by the National Science Foundation.
“The mission of Blue Waters is to support a very diverse and wide range of science at scales and performance levels that are unprecedented,” says Bill Kramer, deputy project director for the Blue Waters Project at NCSA. “At the simplest level, the sustained performance enabled by Blue Waters means scientists can get to the right results faster than anything that exists. It will lead to breakthroughs in what is really achievable by the science community.”
The power of Blue Waters is made available to science teams all over the country, each of which must go through a rigorous application process to be approved by the NSF. Most of the resources will go towards about 35 very critical science and engineering projects, Kramer says. Using Blue Waters, scientists will be able to make new breakthroughs on tough, highly challenging problems such as predicting the behavior of complex biological systems, understanding how the cosmos evolved after the Big Bang, designing new materials at the atomic level, predicting the behavior of hurricanes and tornadoes and simulating complex engineered systems. The contributions of the science teams using Blue Waters will be to enable significant, possibly unprecedented insights using innovative analysis and simulation methods.
The impact of Blue Waters is already being felt. “We had about a fifth of the machine for a select group of science teams that were part of the early process,” says Greg Bauer, technical program manager for the Science and Engineering Application Support Group. “It gave us a three-month window of science at a substantially larger scale. Projects have involved scientists investigating how a virus, such as HIV or polio, can enter and inject their genetic material through the wall of a cell. Or how new proteins are protected while they are forming from RNA sequences.”
Another important early learning has been the tremendous advances in speed and productivity enabled by Blue Waters. “Some of the science teams have been able to do three years worth of what they had normally been able to do in just three months since they got a lot more work done in a much shorter time, which is the working definition of sustained computing” says Michelle Butler, senior technical program manager and head of storage and networking.
“Blue Waters is enabling better science,” Kramer adds, noting that scientists can improve clarity and accuracy by running many more models and simulations in a much more condensed period of time. “Scientists are getting a better understanding of how clouds form. They are getting 100 times more resolution than they have been able to get before, so when you look at something like severe weather — with a tornado, wind temperature, size of land, amount of rain — they are now doing things you can’t study today on any other system.”
Breakthroughs in Storage
In order to deliver these tremendous breakthroughs in science, the team at NCSA had to find a technology partner that could deliver comparable breakthroughs in the underlying storage infrastructure to support capacity and performance requirements that were also unprecedented in size, scale and scope.
Cray has been able to address all of the challenges and do it within a very tight time frame. Cray received the contract in November 2011. As of September 2012 — just 10 months from the signing of the contract — all of the equipment had been delivered and was functioning at scale. The NCSA team cites several critical factors to Cray’s design, including a systematic approach to the entire solution and Cray’s vast experience as the world’s leading provider of supercomputer systems and large-scale parallel file systems such as Lustre.
“What Cray has done is design and build a system that is huge,” Butler says. “I don’t know of any other system with the requirements for scalability that we are putting together for such huge applications. The performance will be above a terabyte per second, which is a measured number on which Blue Waters users will be able to rely. The machine can fill up this file system in a few hours.”
Butler says the systematic approach taken by Cray has been critical in deploying a solution that is highly flexible for scientific applications. “We could have easily spent our money just to support floating-point peak operations, but we put a lot of our investment in the storage system and the amount of memory as well as the compute capacity,” she says. “One of the aspects of Blue Waters is that it’s a very balanced system. We know that the projects approved will be approved for their system science and societal impacts, so we need a balanced system architecture that can address all problems in a very efficient manner. With this system we can move any which way. For example, data-intensive computing or analytics is a rapidly growing area we can support. We aim to be the best in the world at solving problems that are extremely hard — high performance, data coming from anywhere and everywhere at high volumes, data that is not necessarily coordinated, unprecedented simulations.”
The system in place is already using thousands of NL-SAS disk drives, the largest of which are 2 terabytes each. The system also uses solid-state drives for certain portions of the file system. The key is that every aspect of the solution has been built as a single system: All switches, cables, disks and servers are integrated into a single unit. By taking this systematic approach, Cray has been able to reduce power consumption, increase density and deploy the solution cost effectively.
Another important design feature in the storage solution for Blue Waters is the Lustre distributed file system. Cray’s implementation of Lustre provides high levels of scalability, reliability and stability for continuous operations in an open-source, non-proprietary environment. “I’m not sure we could scale any other file system at this point, and even if it could be done with another approach it is even more unlikely we could have done it for the same cost profile. ” Kramer says. “With the Cray Lustre environment we are making that file system highly reliable, highly performant and very usable — not just to be run in a lab but, for instance, it could be used in high-end financial services to predict markets.”
The Impact on Future Storage Systems
The innovations created by Cray in building the Blue Waters storage solution are already making their way into commercial products and many more of the breakthroughs will eventually move out of the scientific community and into enterprise environments. The concept of building an integrated system for scale, performance and cost efficiencies could lead to new approaches for large-scale environments. And, as Kramer notes, Cray’s Lustre innovations could have a huge impact on systems of all sizes and scale.
Other key lessons and innovations from Cray and Blue Waters are coming in from a variety of areas, ranging from backup and archiving to managing both online and nearline storage in an integrating manner to overall management of storage systems of tremendous size, scope and scalability.
“One of the file systems we have on the floor is two petabytes,” Butler says. “We are planning to back that up — but I’ve never backed up two petabytes. We have to learn how we are going to scale our processes to that size of machine. As other companies go to systems of that size, we’ll have broken ground on how to back up, restore and deliver performance. There will be a lot of proving ground that everyone can take advantage of: How do you do quota management at this size; how do you eliminate I/O wait; how do you get a file out of one machine and onto another cache or nearline machine. A lot of these management functions will be in place in a few years.”
Butler also pointed to archiving as a new challenge at such a large scale. “Our nearline subsystem will be on the order of 380 to 500 petabytes, which is accessible to any science team within moments,” she says. “I know of two other archives in the 50-100 petabytes range, but nowhere near this, so it’s another really large deployment where we have to learn about how to manage it, how to scale it and how to manage and assess risks. Also, writing something into this environment — when you are writing data to a single tape, it takes a really long time.”
For tape archiving, the Blue Waters team developed a new technology called RAIT (redundant array of indexed tapes). Kramer says this approach results in improved protection of data at a more reasonable cost than other solutions. “This can have a big impact on cost of ownership,” he says.
Working with Cray to address storage challenges has been extremely important to the NCSA team. “Storage has become more and more important in scientific computing and it has increasingly become a bottleneck in recent years,” Kramer says. “We’ve found that about 20 to 25 percent of teams have been limited by how they are doing file management and data I/O. In areas such as traditional simulation and data collection, we are seeing that they are now coming together and have to be treated simultaneously. It’s a whole new area for data-driven, data-intensive work. Blue Waters will be able to enable that.”
A Unique Responsibility
For the team at Blue Waters and the team at Cray, building these kinds of innovative advances in computing technology is more than a challenge: It’s a unique responsibility. Some of the most important science projects taking place anywhere in the world are dependent on Blue Waters and its underlying storage system to do work that can have a huge impact for generations to come.
“My reason for doing this work versus other things I could do is that we have a lot of motivation doing things that are good for quality of life, that impact science that may even save lives through more accurate predicting of weather, for example,” Kramer says. “We can have an indirect influence on better aircraft design, or how the AIDS virus effects cells, handling the spread of disease, or perhaps developing a new drug. Something like Blue Waters can have an overall effect of making life better for lots of people.”
For Blue Waters to have that kind of impact, the underlying storage had to be rock solid, enabling levels of performance, capacity, scale and scope that have broken — and continue to break — new ground. By breaking down the challenge and taking an integrated, systematic approach, Cray has been able to achieve the necessary breakthroughs to enable new levels in computer storage.