A growing number of companies are deploying flash technology with SSD systems. Though far from perfect, SSDs provide compelling benefits. Enterprises need to balance high costs vs. dramatic performance improvements as SSD storage encroaches on HDD storage in the data center.
Solid state drives (SSDs) came into high-performance enterprise, military and industrial data centers nearly 25 years ago, for niche applications that needed real-time cache and where the environment was too harsh for standard magnetic hard disk drives (HDDs).
While niche markets continue to be havens for SSD technology, it has moved into the storage mainstream. Dell Inc., EMC Corp., Fusion-io Inc., Hitachi Data Systems, IBM, Intel Corp., NetApp, Oracle Corp., Seagate Technology LLC and XioTech Corp. are some of the vendors aggressively pushing adoption of the technology. Worldwide revenue from enterprise storage SSD products increased 53% from 2011 ($1.07 billion) to 2012 ($1.63 billion), according to analyst firm Gartner Inc. "Movement to server and desktop virtualization are driving interest in SSD technology," said Stanley Zaffos, research vice president at Gartner. In these virtualized environments, more data is generated in smaller form factors.
So, what's behind the big attraction to SSD? Performance. An SSD system provides 20,000 I/O processes compared to 200 for HDD storage, according to IBM tests.
Many enterprises need a storage performance boost. With the growing use of multicore processors and the rise of big data analytics, numerous new applications have performance requirements that outstrip HDD capabilities. Solid-state flash technology has the potential to enable new applications or to dramatically improve the performance of existing systems. Early customers have reported that storage response times plummet from 25% to more than 100%.
While flash has many benefits, it also presents challenges. The main issue is price. Hard disk drives cost around 20 cents to 50 cents per gigabyte, while solid-state drives cost $1 to $4 per gigabyte.
Flash technology also requires a fair amount of tuning. Currently, tuning tools are either nonexistent or in an early stage of development. And applications and operating systems may need to be revamped for companies to fully maximize flash's potential.
Reliability is another issue. Solid-state drives have emerged from the consumer market where the workload and reliability requirements are low compared to those of enterprise systems. These new drives wear out faster than HDDs. Companies need sophisticated management tools that will be proactive and ensure that a drive problem will not knock applications offline. The additional maintenance requirements may increase a firm's manpower requirements and hardware costs.
Flash technology at work
Farm Credit Mid-America, a $19 billion agriculture lending cooperative, operates 114 virtual servers running on about a dozen hosts in a data center in Louisville, Ky. The financial services firm, which relies mainly on the Microsoft Windows operating system, has 85 TB of data in that data center and another 75 TB in a backup site.
In early 2011, Farm Credit Mid-America began experiencing performance problems with its Microsoft SQL server and SharePoint applications. "Our X-IO [XioTech] storage infrastructure has been in place for many years and did not offer the performance and scalability that we needed," explained Fred Gordon, systems engineer. Managing the storage infrastructure was also time-consuming.
The company examined products from multiple vendors, selecting EMC's VNX unified storage because it was part of a bundle that included strong disaster recovery functions. It also offered strong block storage functionality.
Farm Credit deployed a flash-first automated tiering system where the SSD storage is used sparingly, basically front-ending its data. As a result, the term tier 0 describes SSD's place in the company's storage hierarchy.
Such an extensive undertaking of storage tiering elicited a learning curve; Farm Credit didn't know where to place its data. The firm had to tinker with its arrays to take advantage of the potential performance boost: monitoring their information flows, placing the data that is updated most frequently in flash and leaving the rest in hard disks.
Once the system was tuned, Farm Credit realized performance improvements ranging from 35% to 80%. The firm also reduced its disaster recovery time frame from 12 hours to less than one via EMC's RecoverPoint.
Finally, there were IT productivity improvements. By automating management functions, Farm Credit reduced the time spent on storage administration tasks by one full-time employee, allowing management to allocate that resource to important projects rather than routine maintenance.
Because SSDs hold information in memory, they do not perform as many reads and writes as hard disk storage, consuming less power. That feature appealed to RTW Hosting, a cloud computing and Voice-over-IP services supplier. "Our energy costs are significantly lower with SSDs than they were with HDDs," said Mike Wills, CEO and founder of RTW Hosting, which relies on XioTech Hyper ISE and ISE-2 products to manage 120 TB of storage.
Paul Korzeniowski is a freelance writer who specializes in data center issues. He is based in Sudbury, Mass., and can be reached at email@example.com.