Everyone agrees that these are early days for cloud storage. Less clear is what the landscape will look like after these clouds mature. Although
Many IT pros, particularly in enterprise shops, don't accept the concept of internal private clouds as anything more than a new name for an old thing. For these admins, the value of calling a virtualized data center an internal cloud isn't apparent.
As Charles Shepard, director of systems architecture at the MGM Mirage in Las Vegas, puts it: "We've been building clouds for years, but we just didn't call it clouds because we didn't have a marketing guy doing IT for us. A cloud to me is a virtual SAN [storage-area network]."
Cloud storage and data availability: Will my data be there?
Early movers in the external public cloud space have suffered while their providers experienced high-profile outages, particularly Amazon's Simple Storage Service (S3). This has led to a widespread perception that third-party services aren't reliable enough for enterprise data.
Availability is among the concerns for Brandon Jackson, chief information officer for Gaston County, N.C., as he evaluates external cloud storage service providers. "Both at the service provider and at our end, is there data center or storage redundancy for the service provider?" he asks. "On our side, redundancy of connectivity would be [a financial] issue for us."
Some say the risk perception can be solved with market education. "Despite the negative publicity due to these outages, few enterprise IT infrastructures are as good," claims a paper written by a research team from the University of California at Berkeley's Electrical Engineering and Computer Sciences department titled "Above the Clouds: A Berkeley View of Cloud Computing."
Jeff Treuhaft, CEO at enterprise cloud storage service provider Zetta Inc., said the service is architected specifically to address the availability issue for enterprises. Availability of the service at Zetta's first data center, opened this year, has been between two and three "nines," while many high-end enterprise storage systems offer five nines of availability. But Zetta customers are automatically credited up to 10% for three nines and up to 25% for two nines without having to prove to Zetta that there's been a problem, according to Treuhaft, and he expects the opening of new data centers this year to improve availability numbers.
Data security in the storage cloud: Who's controlling the data?
Gaston County's Jackson said the potential cost savings of moving to an external cloud are attractive, but so far his evaluation of service providers hasn't led him close to deployment.
"[Another] of my chief concerns so far is security," he said. "Service providers are offering encryption and private networks, but there's a perception [of risk] when data is offsite and out of your control."
Steps are being taken to improve cloud security. For example, LSI Corp. and Wichita State University (WSU) in Kansas partnered this year to open LSI's first storage-focused research facility on the WSU campus, and among the first priorities for the researchers is building a better cloud storage data security mousetrap. WSU graduate student Amarnath Jasti said he is working on next-generation data security technology.
"The challenge is that in the cloud [storage] world, everything isn't controlled by the same entity, including security," Jasti said. "Security profiles that follow data as it moves, along with authentication, authorization and encryption, all need to be researched. Standardization is also an absolute must on this."
Performance is another concern for Gaston County's Jackson. "Service providers are obviously specializing in their service and providing it to other customers," he said. "To what degree are we competing with other customers for bandwidth?"
MGM Mirage's Shepard said that if external clouds ever take off for users like him, it will be after new networking technology arrives and becomes standardized, such as 10 Gigabit Ethernet (10 GbE) and Fibre Channel over Ethernet (FCoE).
"When FCoE becomes completely adaptable and adopted over the next five years, and when it is completely standardized, that is the pathway to develop a full cloud outside our data center," Shepard said. "If you have a big enough pipe, like 10 Gig or even 100 gig Ethernet, you might be able to take a database and write from it to the cloud."
FCoE, which would run Fibre Channel virtual networks over an Ethernet backbone, could also lend itself to multitenant environments, Shepard said. "It inherently sub-segments networks for internal and external multitenant environments," he pointed out.
This is another area where vendors are looking to innovate. Service providers, including Zetta and Nirvanix Inc., say customers are running dedicated network lines to their data center and are starting to explore attaching 10 Gigabit Ethernet lines.
Wide-area network (WAN) optimization and wide-area file services (WAFS) vendor Riverbed Technologies Inc. is developing tools to cut down the bandwidth of data transfers across the wire between local data centers and cloud service providers, though its cloud appliance won't be available before late 2010.
Data migration and hybrid clouds: Can data move on demand?
Data migration is also a thorn in the side of the hybrid cloud storage federation vision promoted by VMware Inc. At this year's VMworld conference in Orlando, Fla., VMware and Cisco Systems Inc engineers demonstrated distance VMotion, but admitted that they've yet to master migrating data on demand as servers shift among geographically disparate locations.
Today, distance VMotion is supported only over distances up to 200 kilometers, and the network equipment prerequisites are beyond the reach of even most enterprise users. VMware and Cisco will only support users attempting distance VMotion over a minimum network bandwidth of 622 Mbps, or an OC12 connection. Here, vendors like F5 Networks Inc. and Network Executive Software (NetEx) Inc. say they can help, but haven't been officially certified by VMware.