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|An eye on SCSI|
"If you are a filer shop and you start having your filer do SANs, it's not like you can buy your switches and your host bus adapters from Network Appliance," says Preston. "A filer vendor in the SAN space won't have the traction to ensure interoperability."
In fact, Preston urges companies to carefully consider avoiding SAN deployments, if all they want to do is build a highly scalable file-based storage infrastructure. As an example, Preston tells of one large Fortune 500 company that was looking at deploying SAN solutions from EMC and HDS, and at the last minute, decided to bring NetApp into the picture as a third option.
"[NetApp] ended up doing very, very well in comparison to EMC and Hitachi, and their price was much less," says Preston. He adds: "If you are doing file, you should look at all the file options."
That's essentially what Buckeye Color Labs, a North Canton, OH-based photo service bureau, did, but with an interesting twist. It deployed FalconStor Software Inc.'s IPStor after a surge in storage demand strained its DAS. With the number of servers rapidly growing, the company turned to Cleveland-based consulting firm Chi Corporation to help deploy IPStor on a single Intel-based server running Linux.
IPStor's virtualization features allowed the company to reuse its existing disks, running them in a JBOD array from Chaparral Network Storage, Longmont, CO, alongside two new ATA disk arrays from Woodland Hills, CA-based Nexsan Technologies Inc. Most important, the solution allowed the company to access the disks via a direct SCSI attachment, sidestepping the significant costs of a FC array. Jeff Manuszak, senior engineer at Chi Corp., says the infrastructure can scale to 12TB before the number of required SCSI connections forces a switch to FC.
Virtualization can also be a way to get around vendor lock-in. Both DataCore's SANsymphony and IPStor make it possible to unify block and file data access, while drawing disks together into a single, centrally managed pool of storage.
A new take on this approach comes from Maxxan Corp., San Jose, CA, which is just releasing its first-generation MXV320 intelligent switch for general availability as we go to press. Users can deploy blades on the switch (or in a standalone box) that run either FalconStor's IPStor virtualization server or Microsoft Windows Storage Server 2003 to provide file services on back-end SAN storage NAS vendor Z-Force, Santa Clara, CA, offers yet another spin on virtualization, selling file switches that link heterogeneous NAS devices to create a single, logical volume. The ZX-1000 switch sits between the NAS filers and the hosts and clients that access them to scale both performance and capacity. Company officials say that it could be made to work as a gateway, but it hasn't done that yet.
Even as vendors tout the benefits of convergence, some storage consultants question the wisdom of such an approach. The Storage Group's Preston argues that the converged SAN-NAS product segment is more a product of vendor positioning than actual user need.
Says Preston: "I know of no one who said 'Gee, I wish my NetApp could do block.'" But he adds, "I do know NetApp and EMC salespeople who got tired of losing sales because of the other side's capabilities."
Jim Damoulakis, chief technology officer for GlassHouse Technologies Inc., Framingham, MA, says he has found interest in converged SAN-NAS solutions to be slim. "We have not seen a large number of examples of this," he says.
Take BMO Financial Group, which has left its direct-attached file-based storage in place while focusing on extending SAN operations. Brian Black, vice president of application management services at BMO Financial Group, says the bank operates a fast-growing, 50TB FC SAN that is built on HDS and IBM Shark arrays. Black says the bank has no immediate plans to transition its direct-attached file-based storage to the SAN. "The predominant strategy now is on new projects and getting them on to the SAN," Black says.
Northwestern University in Chicago places similar emphasis on its SAN operation. The university maintains a 10TB to 12TB IBM Shark-based SAN, which houses an Oracle database and various administrative applications. Another 5TB of file-based storage is contained on Dell PowerVault NAS boxes, which provide shared file access on the Ethernet network. Dana Nielsen, director of the data center and vice president of information technology at Northwestern University, says there are no plans to unify the NAS and SAN infrastructures.
Arun Taneja, president of consulting firm The Taneja Group, Hopkinton, MA, says the best move for many companies may be simply to wait. "The real convergence is going to be when your tools are consistent. NAS tools are totally different from SAN tools today," Taneja says. "We're still in the infancy stages on the NAS management side, and we're in the first generation of SAN management products."
This was first published in September 2003