Disaster recovery driving WAN for storage

Storage spending patterns show disaster recovery (DR) is fueling the use of wide-area networks (WANs).

The focus on the wide-area network's (WAN) role in storage appears to be shifting from providing wide-area file services (WAFS) for remote offices to enabling disaster recovery.

Storage spending surveys indicate WAN purchases have been dropping in recent years. However, when organizations do invest in storage for the WAN, it usually involves a disaster recovery component as companies increasingly set up secondary sites to recover data in case of failures.

The WAN comes into play with storage mostly when trying to connect remote-office devices to primary central file and backup storage, and storage systems in different sites for DR and archiving.

"More people are leveraging [WAN optimization] for DR, especially smaller to midsized companies," said Bob Laliberte, an analyst at Milford, Mass.-based Enterprise Strategy Group (ESG). "They're creating their own secondary DR sites. Two things helping to drive disaster recovery are VMware and WAN optimization. VMware can reduce the number of physical servers and infrastructure at the second site, and WAN optimization can help reduce network costs."

People started paying a lot of attention to storage on the WAN a few years back when a slew of WAN optimization and WAFS products were launched from established networking vendors as well as startups. The field has been thinned by acquisitions, but Blue Coat Systems, Cisco Systems Inc., Citrix Systems Inc., Expand Networks, F5 Networks, Juniper Networks, Network Executive Software Inc. (NetEx), Riverbed Technology Inc. and Silver Peak Systems still sell these types of products.

Since then, backup applications aimed at remote offices such as Asigra Inc. Televaulting, CommVault Simpana, EMC Corp. Avamar and Symantec Corp. PureDisk, as well as cloud vendors have expanded the way the WAN is used for storage. Microsoft Corp. is also poised to make a run at WAN optimization with features built into Windows 7, which is scheduled to become commercially available this year.

WAN use for disaster recovery on the upswing

In a new Storage magazine/SearchStorage.com purchasing survey of more than 700 organizations, 25% of respondents said they will increase WAN spending this year vs. 36% who said they would increase WAN spending in a spring 2008 survey. Only 11% said they would buy WAFS in 2009, down from more than 20% two years ago.

However, storage administrators expect to spend more money on the WAN for disaster recovery this year. Half of those who say they'll make WAN-related storage buys cited DR as the main reason, up from 44% last year. Using the WAN for connecting data centers (25%), connecting branch offices (21%) and automating backups (20%) were in slightly fewer organizations' plans this year vs. last year.

Market research from TheInfoPro (TIP) shows WAN acceleration is far more prevalent on the network side of Fortune 1000 organizations than the storage end, with Riverbed and Cisco being the most common choices for storage and networking, respectively. Interest in wide-area file services overall is waning, but companies already using WAFS are expanding their use of the technology.

According to TIP's most recent round of research, only 16% of Fortune 1000 companies use WAFS for storage and 63% have no plans for it. However, more than 50% of the firms using WAFS for storage plan to at least double their installations this year. Half of the companies surveyed by TIP who said they're using WAFS run Riverbed Technology, followed by Cisco as the next most deployed.

"With budget constraints, people have been pushing things into long-term plans instead of near-term, and strategic projects such as WAFS have been pushed off," said Rob Stevenson, TIP's managing director of storage research. "But satisfaction among those who have WAFS seems to be positive."

Stevenson said in talking to companies for TIP's next round of research, he detected more interest in organizations using Riverbed's Steelhead and EMC's Avamar data deduplication products for remote-office DR.

Moving to the client

ESG's Laliberte also maintains the technology is now more frequently used for more than connecting data centers to other data centers or to remote offices.

"WAN acceleration is moving to the client," he said. "Vendors are coming out with client software. It's not just remote office to remote office or data center to data center now -- they're also being used for mobile users."

Stephen Foskett, director of data practice at storage consultancy Contoural Inc., agrees that WAN optimization is moving to the client. He said Microsoft has useful tools for remote offices built into Windows 7, including BranchCache and enhancements to the Server Message Block (SMB) service that enables file and print sharing.

BranchCache lets Windows 7 computers on the network cache content and share it with other Windows 7 clients at remote offices.

"You bring up Windows 7, and all Windows 7 machines in the remote office will work together to cache files," Foskett said. "The new version of Microsoft SMB itself has WAN acceleration built in. It cuts down the number of transactions before you get data, combining requests into single transactions instead of sending multiple transactions."

Foskett said cloud services are also used to improve performance over networks. "We're seeing those used in a different [way] for applications that can tolerate the network speed. Instead of trying to overcome the network speed, it's tolerating the network speed for applications where it makes sense."

Of course, speeding files and applications over the network remains a core function of WAN optimization for storage.

Thomas Fenady, senior director of IT at Activision Publishing Inc., told Storage magazine last year that his company went from sending 8 MBps to 34 MBps over an E3 line after installing a Riverbed Steelhead appliance. That substantially reduced the time his developers (spread across 67 international offices) could transfer files to build video games.

Logistics service provider Transplace uses SilverPeak NX appliances to replicate 10 TB of production data and applications from its Dallas data center to a DR site in Lowell, Ark.

"Without SilverPeak, we would not be able to replicate the amount of data we're replicating without increasing bandwidth," said Scott Engle, Transplace's director of IT infrastructure. "We're getting from 3.5 to five times the traffic on that DS3 link as before on average, and I've seen it as high as 28 times."

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