Micron SSDs can deliver system-level advantages, even when IOs and throughput aren’t critical.
There’s an old saying that “the cobbler's kids always go shoeless.” This concept can be particularly true in our industry as we build new, cutting-edge solid state storage products with our customers’ needs in mind. But at Micron, we want to make sure that our own business can realize the benefits of the technology we create too. We’re working hard to ensure that we try on all the latest “footwear,” right here in our own shop, and take every advantage of our own technology while helping to ensure we’re putting products into the market that are up to our own standards.
An Enterprise Data Center in our own Backyard
Micron is a large enterprise, with a wide variety of computing applications and data storage needs. The urgency of adopting newer, faster data technologies varies across the enterprise. As a semiconductor manufacturer, the amount of data gathered and evaluated for quality control and process improvement is enormous. A world-wide operation like Micron, with factories spread around the globe, demands nimble decision making. There are thousands of employees who are using office productivity and communications applications familiar to all industries.
All this gives Micron’s SSD team ample opportunity to experiment with new applications for SSD products. Our IT managers are often eager to volunteer to see where SSDs can help Micron maintain its competitive edge.
Communicating at the Speed of Flash: Skype™ for Business
Within Micron’s SSD business is a team of dedicated engineers called the Storage Solutions Engineering group, focused on applying our latest technologies to make the enterprise faster, better and more reliable. This team is tasked with finding new ways to apply SSDs to solve common business problems. The team has a lab dedicated to such experiments, but we also use Micron’s IT department as a proving ground.
One of the most widely used applications within Micron is Microsoft Skype™ for Business. Skype provides us with fast and easy worldwide audio and video communications and file sharing, within our company, as well as with our partners and customers.
So, our Skype servers were a natural target to see what sort of improvement we could get by upgrading to from HDD to SSD.
Some Surprising Results
Maybe it’s a little counterintuitive, but there are applications where faster storage isn’t an immediate concern. Skype is one of those. It turns out that the compute activity of the Skype for Business server is extremely memory intensive, so disk IOs are less important than in other applications. For our system which supports hosting at least 10,000 users, we measured write activity at around 60 writes/second, regardless of the storage medium. At this level, the storage is barely breathing hard!
Our Skype servers are running on standard 2U / 2 CPU platforms. As configured, these servers each include eight 146GB 15k rpm SAS HDDs. Two of these are in a RAID-1 system disk, and the other six are configured in RAID-10 for the data disk.
We decided to go “all SSD,” putting two Micron SSDs in RAID-1 for a fault-tolerant system disk. Next, we replaced the six data HDDs with two Micron M510DC enterprise-class 600GB SSDs for data, also in a RAID-1. This gives us an increase in capacity from 438GB to 600GB, while preserving fault tolerance.
The Hidden Advantages of Flash
Even when data storage IOs are not as critical, there are other advantages which flash can bring. In this case, we did see some advantages in power consumption, and a longer-term projected advantage with regard to system reliability.
In our SSD-based systems, there was a noticeable reduction in workload on the system processor. This, along with the lower average power consumption ratings for SSD, and the lower drive count for the SSD configuration, resulted in a significant reduction in power consumption over the 24-hour experimental period. The SSD-based systems averaged around 130 W of power consumed, while the HDD-based systems consumed an average of 175 W. This 25% power savings could be significant, especially in areas where utilities are expensive.
Reliability is a key advantage for SSDs, helped by the lack of moving parts in each drive. The M510DC has a mean time to failure (MTTF) rating of 2.5 million hours, vs. the typical MTTF rating for enterprise-class 15k HDDs of 2 million hours. Over time and over a population of drives, this is a 20% reduction in field failure rate.
In turn, our configuration allows us to take further advantage of SSD reliability. Recall that our HDD configuration system had six data drives, while our SSD configuration only needed two data drives to attain the same performance, also tolerating a single drive failure. It turns out that the reliability of a given system is directly related to the number of components included in the system. So, a 6-drive system will have a higher failure rate of a 2-drive system. In either of our cases, a single drive failure can be tolerated, but presumably, a technician will be called immediately to service the single bad drive, before a second fails and takes down the system. This means that a technician could be spending more time in maintenance and repair of the HDD-based system as he would with the system including the M510DC, even before counting the better MTTF rating for M510DC.
Even when disk IOs and data throughput are not a large concern, SSDs can deliver some key advantages. The ability to deliver equivalent or better performance with fewer, more reliable devices has positive implications for power consumption and for the overall reliability of a computing system. Look for other fascinating results, solutions briefs, and reference architectures at our Micron Accelerated Solutions page.
About Our Blogger
Jon is a Senior Technical Marketing Engineer for Micron's Storage Business Unit, with a focus on client solid state drives.