The Enterprise's Open Storage Quandary
Nov 12, 2010 7:20 AM PT
Enterprises' need for storage is increasing exponentially as businesses use more and more rich media such as audio and video both within their networks and on customer-facing websites.
That demand is going to continue growing, driven both by customer demand and demand from new hires who grew up with the Internet and want the same ease of use and features they already have at home.
However, storage is expensive, and a decent subsystem runs into the multiple tens of thousands of dollars. This is driven many corporations to consider cloud computing and cloud storage solutions, and the Storage Networking Industry Association (SNIA) earlier this year put out a paper on managing private and hybrid clouds for data storage.
Open storage systems are generally less expensive, but despite this, many enterprises elect to remain with their proprietary storage solutions.
"Customers may be on the bleeding edge when choosing applications, but when it comes to fundamental infrastructure like storage, they're risk averse," Sakthi Chandra, senior director of marketing at Nexenta, told LinuxInsider.
Money Isn't Everything
Why wouldn't enterprises leap onto the open storage bandwagon, especially in these tough times?
The answer is complex. Open storage is useful in certain circumstances, but may not be suitable at other times, and some enterprises are working judiciously with a mix of both.
Even calculating savings due to using open storage isn't a simple matter.
"It isn't simply a matter of cost so much as it is cost for relative performance," Charles King, principal analyst at Pund-IT, told LinuxInsider. "If a company's storage requirements are relatively simple, open source products could be seen as viable alternatives to proprietary solutions."
Some open source solutions are being optimized or integrated for specific solutions, King said. For example, the ZFS file system, developed at Sun Microsystems, is being used in Oracle's Exadata solution. Oracle owns Sun, by the way, so perhaps that factored into the equation.
However, "I'm not certain what the future of ZFS or the other open source projects at Oracle will be," King remarked. "Mike Shapiro, who led the ZFS development team, was one of the three inventors of DTrace diagnostics and was vice president of open storage at Oracle, resigned recently. All three of the DTrace engineers have left Oracle, as have several MySQL engineers."
ZFS is a combined file system and logical volume manager designed by Sun Microsystems that offers support for high storage capacities, integration of the concepts of file system and volume management and offers snapshots and copy-on-write clones. Other features are continuous integrity checking, automatic repair and Raid-Z. It is implemented as open source software.
DTrace is a dynamic tracing framework created by Sun for troubleshooting problems in kernels and applications in production systems in real time. It has been released under the Common Development and Distribution License.
The Old Order Changeth
The drive toward virtualization and its complement, cloud computing, are forcing new approaches to storage, Nexenta's Chandra suggested.
"In the past five years, there's been a shift in how IT approaches infrastructure that has been driven by the reality of virtualization," Chandra explained. "Further, the idea of cloud computing gives you great economics -- if you look at Amazon's S3, the pricing of storage is down to cents per terabyte depending on when you look at its pricing, and IT is questioning why its internal IT structure can't match that cost."
Virtualization and the cloud are forcing IT shops to reevaluate their broad storage strategy, Chandra said.
Take the issue of desktop virtualization, for example. "When you virtualize your desktops and move compute resources back into the data, it impacts the network," Chandra pointed out. "Also, you're taking the data on commodity storage from your laptop and pushing it back into data center storage, which is provided by SAN and NAS vendors. The costs don't add up."
The problem isn't one of adding more storage subsystems but of keeping storage capabilities in lockstep with virtualization, Chandra said. ZFS lets users bring on "thousands of machines in minutes instead of hours" because it allows unlimited snapshotting, he added.
Virtualization issues like this are forcing IT to fundamentally rethink storage and consider how to accommodate virtualization, bringing in the economics of cloud computing, Chandra said.
For example, traditional storage systems offer hardware redundancy in RAID (Redundant Arrays of Inexpensive Disks) configurations, but open source solutions go beyond that problem altogether.
"The fundamental assumption ZFS makes is that your hardware systems are bound to fail," Chandra remarked. "So we take the approach that it's the software's responsibility to provide consistency throughout the lifespan of the data. Using copy on write, every time before we do a write of the data, we copy it and make sure it's available in an open storage disk somewhere else."
Hopping Onto the Open Source Train
However, proprietary storage systems vendors haven't been napping at the wheel.
"One of the way that vendors of proprietary storage systems have maintained or increased the innovation of their products is by incorporating increasingly sophisticated software functionality that's difficult for open source vendors to keep up with," Pund-IT's King pointed out.
Add that to the trust built up over years of business dealings, and proprietary storage product vendors appear to be in a good position.
However, "One of the issues with the big guys is that their architectures are rooted in legacy design and the applications that are becoming more and more popular today are very different from those written 10 to 15 years ago," Jack O'Brien, vice president of marketing at Gluster, told LinuxInsider.
"Everything's more dynamic now, everything's designed to be stored in the virtual server environment," O'Brien explained. "Today the unstructured file base data is exploding, and people are looking to move off the legacy systems because these aren't meeting their requirements."
The Open Window of Opportunity
Storage virtualization technology lags behind server technology, and that provides a window of opportunity for open source storage solution vendors, O'Brien pointed out. "Traditionally, people went with SANs for virtual storage but that meant they had to provision one SAN for every virtual machine. The situation's better now but you still have to provision a lot of storage and manage a lot of LAN connections, and have to deal with input/output (I/O) bottlenecks."
Open source storage solutions are able to run huge files, and expanding them is relatively easy. "We can scale to petabytes, so you can create as many virtual machines as you want and take as many snapshots as you want," O'Brien said. "We put everything under one large single global name space that any number of virtual machines can access at one mount point. If you need more I/O you just scale out your hardware, unlike proprietary systems where you have to go buy a new system or do a forklift upgrade."
Further, open source storage solutions are becoming more sophisticated as third-party add-ons that offer high-end features evolve. For example, OpendedUp, an open source deduplication file system for Linux that's also known as "SDFS," emerged in March. This is designed for enterprises with virtual environments looking for a high-performance, scalable deduplication system that's not too costly.
Other open source add-ins that provide storage management are also emerging, signaling a move among open source storage solutions towards meeting the needs of the enterprise.
"Open source serves the needs of smaller companies with a cost-efficient alternative, and forces innovation and service from proprietary vendors," Jake Sorofman, chief marketing officer at rPath, told LinuxInsider. "Whether or not open source is a true alternative in a given category, it typically creates advantages for end user enterprises and forces commercial providers to deliver more innovation and value."
It's not likely that open source storage solutions will supplant traditional ones. It's more probable that, like other new technologies in computing, they'll alter the face of their industry but then they'll coexist with existing solutions.