So far the "VM" in VM-aware storage stands more for VMware than for virtual machine. Most vendors in this market develop their systems for VMware vSphere, the dominant hypervisor on the market.
However, that is starting to change. For VM-focused storage vendors to maintain their momentum, support for hypervisors other than vSphere seems to be both inevitable and necessary. The rise of Microsoft Hyper-V is the main reason, although other hypervisors are also in use.
VM-aware storage vendors such as Tintri, and the hyper-converged vendors Nutanix, Scale Computing and SimpliVity, offer storage designed to address the complexity of managing storage in heavily virtualized environments.
Administrators can provision storage on virtual machines (VMs) rather than dealing with the LUNs and volumes of a traditional storage environment.
VM storage products from Tintri and SimpliVity are built to be hypervisor-agnostic, but they only support VMware. Nutanix supports VMware and the open source KVM platform. Jeff Ready, Scale Computing's CEO, said he is careful not to become too reliant on VMware because VMware parent EMC is a rival storage vendor. Scale embeds KVM natively into its arrays, but customers can connect severs running VMware to Scale's storage.
Tintri, Nutanix and SimpliVity plan to roll out new versions of their VM storage systems in the coming months, but none have confirmed a specific point at which additional hypervisors will be supported. However, all three say they have support for additional hypervisors on their roadmaps.
They have little choice. A recent Enterprise Strategy Group survey found that 65% of respondents were using more than one hypervisor.
"Because more companies run multiple hypervisors than not, I think [supporting more than VMware] is going to be critical to advancements," said Terri McClure, an MSG senior analyst.
That means customers of VM-aware and hyper-converged product systems are likely to have more than just VMware.
"People are doing the same thing with Hyper-V [as with vSphere], so it's very important for us to provide support for that, and there is interest there. We'll add support for that later, for sure," said Howard Ting, vice president of marketing at Nutanix.
Use of more hypervisors will likely drive more need for storage created specifically for virtual machines. VM-aware and hyper-converged products are trying to help storage catch up to what virtualization has done for servers.
"Virtualization has been going on for quite some time, for 10 or 12 years, and during that time, VMware has done a really good job of virtualizing the server infrastructure … but we're finding that storage is really lagging far behind," said Ed Lee, lead architect for the Mountain View, Calif.-based startup Tintri.
"Management of storage infrastructure in virtual environments really requires managing [servers and storage] completely separately, and doing a lot of advanced planning to make sure you group them with the right VMs and right LUNs that are properly replicated. That just makes it very labor-intensive, complicated and difficult to maintain."
This complexity also makes fixing bottlenecks a difficult task. "It's not just that the bottlenecks happen," said Jeff Byrne, an analyst at Hopkinton, Mass.-based Taneja Group. "When the administrator actually has to go and figure out what's happening, it's very difficult -- because you're trying to map this virtualization construct on top of a traditional storage construct, and the two just don't blend very well."
That same challenge is pushing the adoption of hyper-converged systems, as well. These systems provide storage, compute and hypervisors in one box, allowing all management to be contained behind one pane of glass.
"There's intercommunication amongst all these building blocks," said Tom Grave, vice president of marketing for Westborough, Mass.-based hyper-converged vendor SimpliVity. "If you want to move a VM you just use [VMware] vMotion like you always do, but then the system is smart enough to drag the storage along with it; I think that's one of the main drivers."
Those systems eventually must be smart enough to drag storage connected to other hypervisors, too.