Virtual storage schemes are becoming as varied as their physical counterparts, as the industry struggles to bring the benefits of consolidation and increased utilization to the data farm.
The sheer number of storage options centered on the VMware platform alone gives you some idea of the myriad choices IT managers face. This article at Enterprise Storage Forum delves into the multiple approaches taken by LeftHand Networks, EMC, IBM and others looking to leverage the Virtual Tape Library (VTL) and Virtual Consolidated Backup (VCB) tools on the VMware ESX Server.
Other vendors are heading out in new directions. Startup Parascale has developed the Virtual Storage Network (VSN), using Linux servers to form "file grids" in which a single storage node can control multiple nodes to provide petabytes' worth of virtual storage capacity. The company pitches it as a low-cost, more reliable approach than clustered NAS solutions.
If you're looking to build virtual storage from the ground up, you might want to check out the virtual version of Hitachi's Universal Storage Platform. The system can virtualize and thin-provision storage from any vendor, and the Universal Volume Manager can support up to 96 petabytes of virtualized storage.
Meanwhile, DataCore is looking to pull the industry away from fixed, single-purpose hardware toward a more flexible, software-based infrastructure. It's doing that by placing its SANmelody and SANsymphony systems directly onto the virtual machine created under VMware, XenSource, Microsoft and Virtual Iron. The company says this opens up new possibilities for consolidation and collaboration with virtual environments because they're not tied down by the complex mapping systems and other physical limitations of the hardware.
Of course, all virtualization systems have to deal with hardware at one point or another, and that's where the virtual server/storage conundrum comes into play. With processing speed increasing at a much faster rate than storage and I/O capabilities, the server side of the house will always promise greater performance than the rest of the network can cope with. Maybe virtualization will help even the score, but unless there are significant gains in physical storage and I/O devices, there's only so much it can do.