It's that time of year once again, so we spent the last few days chatting with analysts and vendors to see what they think will be the dominant trends in storage for 2008. To sum up, it's all about the green — saving money with virtualization, iSCSI and SATA/SAS, and saving power with green storage.
Virtual Reality
While the server world has rushed headlong into virtualization in recent years, storage virtualization has been lagging far behind. Not for much longer, though.
"Virtualization will become increasingly important both for storage and servers," said Mike Karp, an analyst at Enterprise Management Associates. "The challenge here will be managing across the two virtual interfaces — the abstraction layers that separate the physical devices from the management."
The challenge will occur in situations where the various virtualized "domains" intersect with one another, where, for example, it is necessary to manage storage within the context of its connection with application servers. Increasingly, these servers will turn out to be blades. They have become the core component of a virtual data center infrastructure, since they provide a common platform for virtualization where resources can be easily shared. But with so much now depending on that environment, high availability and recoverability become critical. And that's where storage comes in.
Virtualization, after all, allows multiple virtual machines to run in a single physical server. This means that a hardware failure has the potential to bring down eight to 10 servers at a time, so the scale for potential disaster grows exponentially. As virtualization starts to gain momentum, then, there is going to be an increased need for failover at the host controller level to ensure that there are multiple paths to the drive arrays in the event of a hardware failure.
"With the increase in virtualization, and the fact that more applications are being consolidated on fewer, better utilized servers, the need for high availability increases significantly," said Andy Scholl, manager of virtualization at HP. "As a result, more and more customers are adding virtualization to their disaster recovery solutions. Additionally, a great deal of network storage is being sold into virtualized environments and is on the rise for improved replication."
Virtual storage, therefore, will certainly be in vogue for 2008, offering ways to simplify storage management and reduce data center costs.
"It will be interesting to see whether data center managers will be comfortable storing their data virtually without having exact knowledge of where their data resides," said Gary Gysin, CEO of Asempra Technologies.
Accordingly, Asempra is one of several vendors seeking to virtualize the entire data protection and recovery process. The idea is to make it transparent to the user, the application and IT so recovery can take place as fast as 30 seconds after a storage failure, instead of hours or days with traditional data protection and recovery processes.
I See iSCSI
Another area that comes up repeatedly is the continued march of iSCSI SANs as a low-cost, reasonable-performance alternative to Fibre Channel-based (FC) SANs.
Greg Schulz, an analyst at StorageIO Group, predicts "continued adoption of iSCSI and NAS for IP-based storage."
While the progress of iSCSI-based SANs has been slow but steady, it's reached the point where, because of the near parity of the two technologies, the decision between iSCSI and FC can now be based on non-technical criteria.
"ISCSI performance still lags FC performance, but it's very competitive," said Karp. "Additionally, the old idea of FC for mission-critical applications, while leaving less important applications for iSCSI, is no longer valid."
The fact that iSCSI is a true competitor for data center dollars was demonstrated most recently when Dell announced its intention to acquire iSCSI SAN provider EqualLogic.
Longer-term, iSCSI will likely have to contend with Fibre Channel over Ethernet (FCoE), but that's a story for another year.
Getting SAS-y
In tandem with the rise of iSCSI is the use of SATA and SAS as a means of establishing an inexpensive tiered storage hierarchy.
"We'll see an increased presence of lower-cost SATA disks on the IT room floor," said Karp. "As managers start to realize that the incidence of failure of lower-priced disks is essentially the same as that seen with more expensive disks, I fully expect more of the lower-priced disks to appear as part of top-tier storage arrays, at the expense most frequently of Fibre Channel devices."
In all likelihood, SATA will remain the cost- and performance-optimized interface for the majority of value-end storage appliances that employ a fixed number of drives to serve vertical applications such as video surveillance. SAS, on the other hand, will probably emerge to capture the direct-attached server space, SCSI's former mainstay. And mission-critical applications that require higher levels of availability and native expansion will increasingly rely on SAS.
"We will see the growing market acceptance of SAS as it gradually replaces the SCSI infrastructure and complements the SATA space," said Barbara Murphy, senior vice president and general manager of Applied Micro Circuits Corp. "The coexistence of the two serial interfaces will give integrators unprecedented opportunities to choose the interface technology that best fits their customers' requirements as they build systems for their particular storage environments."
AMCC, for example, has a serial storage product portfolio that includes 2 to 24 ports of SATA connectivity and SAS expandability up to 128 devices per controller. Further, the emergence of lower-cost 10Gb Ethernet switches from companies like Arastra ($400/port 10Gb Ethernet switch — a tenth of the price of the current switch technology) could well ignite the introduction of 10Gb Ethernet in the data center.
"The enhanced feature set of SAS marries well with the other major trend in 2007, server virtualization," said Murphy. "Since SAS allows for large-scale storage expansion, I see the emergence of direct-attached environments with SAN-like capabilities. This will create exciting opportunities for companies like 3ware to satisfy the demand for high-performance, high-capacity RAID controllers."
Green Storage
One final trend bears mention — green storage. There are now plenty of initiatives around that promote environmentally conscious computing. These are now starting to take serious hold in the storage sector.
"2008 will be marked by a greater understanding of the many different faces of green storage and its linkage to power, cooling and floor space," said Schulz (see Storage Power and Cooling Issues Heat Up).
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