Virtual storage appliance expands beyond SMB use into enterprise

VSA software has expanded beyond the SMB market to enterprise use with products featuring higher performance and scalability.

Right now, virtual storage appliances (VSAs) that promise higher performance and scalability than prior-generation models are giving small- and medium-sized businesses as well as enterprise users an alternative to traditional disk arrays. In fact, consultancy Taneja Group Inc., based in Hopkinton, Mass., predicts that VSAs will ultimately be a disruptive technology in the storage marketplace.

VSA software runs in a virtual machine and creates a shared-storage environment using the storage of the physical server on which it runs. Current virtual storage appliance offerings include both general-purpose products and software targeted for special functions, such as backup and disaster recovery, noted Jeff Boles, a senior analyst at Taneja Group.

Boles offered up advice on the different types of VSAs, the latest innovations and the expanding use cases in the following podcast interview with senior writer Carol Sliwa. How do you categorize the current crop of virtual storage appliances?

Jeff Boles: Let me start with a little bit on how virtual storage appliances came about, and then I'll categorize what we have out there today. The VSA, or virtual storage appliance, idea came about several years ago in the heyday of the first general virtual appliances. I think the earliest offering was maybe HP's LeftHand VSA, which today has recently been turned into the HP StoreVirtual VSA. The idea struck vendors at the time that most software code they were writing for the x86 processor that resides in most modern storage controllers could easily be turned into a virtualized product.

Understandably, most vendors have been a little hesitant, though, to jump on this bandwagon because it is hard to fully control that virtual environment that they're going into and promise what they can deliver in terms of performance because of that. But, they're also hesitant because it's hard to figure out where VSAs fit in the current physical system product portfolio. Conceivably, you could do both small storage and really big storage when you have good scale-out architectures.

Today, we have a mix of offerings in the marketplace. … First, you have general-purpose storage appliances for what I consider to be two generations. The first-generation products are typified by restricted features and capacity. More recent second-generation offerings that are general-purpose storage appliances are starting to look and perform just like the physical storage system they are virtualizing, meaning they have fewer node limitations and can scale to deliver just as much performance as a physical system. Another just as important type of virtual storage appliance is a special-purpose appliance typically targeted at backup. In what scenarios do virtual storage appliances provide the greatest benefit?

Boles: Offerings in the market today lend themselves to a couple of scenarios. First, those special-purpose appliances can often help tackle a big challenge, like VM backup, with Quantum's vmPro or Acronis' vmPROtect type offerings, or even DR protection with cloud gateways that can help create cloud storage offsite for recovery in case of a disaster. As an example, disaster-proof protection is a particularly noteworthy capability of something like Riverbed's Whitewater backup appliance. That can be deployed as a VSA to serve as both a deduplicating backup target and a cloud gateway that replicates highly deduped and compressed data to the cloud. [It has] practically unlimited storage capacity and easy disaster-proof data recovery to any virtual infrastructure, like an Amazon cloud or a hosted cloud somewhere.

Second, the two generations of general-purpose VSAs I talked about can help customers with a few things. For many SMB customers, many of these products can act as their primary storage system in a small environment, and they can help simplify storage deployment and management.

Alternatively, many of the VSAs can also act as a conduit to store data on a bigger system while allowing the virtual infrastructure administrator to take on some of the storage management without having to touch a storage system that supports the entire business. This model also adds benefit in a cloud or even in branch offices where physical storage isn't easy to deploy and manage and remote data is hard to deal with. A VSA can serve up much of the same functionality for remote locations that is used in a data center and, paired with replication tools, can serve as a conduit between a local and a remote virtual data center, effectively keeping data consolidated.

Just recently, a few vendors have made their offerings much more serious, and they're starting to look like a serious alternative to a physical array altogether. HP recently moved in this direction with [StoreVirtual], and Mellanox just showed off a VSA that utilizes some of Mellanox's protocol and remote direct memory access (RDMA) expertise to deliver serious performance.

Both appliances can scale out across multiple hypervisors. As an example, Mellanox claims to have measured 139,000 IOPS per VSA and 4.5 GB of bandwidth per second using just two virtual machine clients with everything running on a single hypervisor. So, that stuff becomes extremely scalable and extremely high-performance with a good architecture and can serve the primary storage needs of many different types of customers, including large enterprise-type customers. But, is the main target audience for virtual storage appliances still small- to midsize businesses?

Boles: With these latest offerings I just mentioned, VSA is rapidly becoming a technology that could be useful for all sizes of businesses, from the SMB and SME up to the largest enterprise. When you take … data protection under consideration, most infrastructures likely already have some form of a VSA in use. We've long been of the mind here at Taneja Group that VSAs will ultimately be a pretty disruptive technology to the storage marketplace as server power continues to increase and denser, higher-performance technologies like solid-state drives (SSDs) become more affordable. VSAs may rapidly become the go-to storage solution for virtual infrastructures. And, those virtual infrastructures make up a majority of the global data center workloads today. That's why everyone is getting into this game, from NetApp with OnTap-V and FalconStor to Veeam and VMware itself with VSA and their new vSphere Data Protection (VDP) offering and the aforementioned Quantum, Acronis, HP and Mellanox offerings. What are some of the major innovations you've seen with the latest wave of virtual storage appliances?

Boles: I typically identify three innovations that are particularly noteworthy accomplishments. One is scale. Vendors are starting to introduce technologies that can scale out across hypervisors. This can pool and aggregate a lot of storage resources and put them in one, single, easier-to-manage storage repository that has pretty sophisticated features wrapped around it, making storage in a virtual infrastructure seem really enterprise-ready, even when it's delivered with VSAs.

The second is performance. Vendors are getting real serious about performance, like I just pointed out with Mellanox and HP with their scale-out StoreVirtual architecture. And, they're doing some serious stuff under the covers that harnesses some storage from the local hypervisor in a very efficient way, and that's particularly notable when you're thinking about SSD in the local server.

Third, vendors are delivering even easier-to-use products and better packaging in these VSAs to make them particularly attractive for the SMB or overloaded admin. What advice do you offer to organizations considering virtual storage appliances?

Boles: It's absolutely time to be hands on with VSAs in some way or another. VSAs will continue to advance albeit probably slowly compared to the general storage landscape, but they'll likely someday shake up how storage is done in a virtual infrastructure. So, today, you should be negotiating with your storage vendor to get some of their VSAs in place even just on a test-lab or experimental basis and be looking at how these products might enhance the functionality of the virtual infrastructure and help increase capabilities or reduce current hassles.

Any time data management and virtualization cross their IT radar simultaneously, practitioners should be thinking about whether there might be a VSA that solves a particular problem, whether it's branch office and data consolidation [or] replication and DR, or we could probably conjure up another dozen examples. In many cases, a VSA might solve a problem more cost effectively and potentially with greater flexibility than a traditional appliance.


As you look at your solutions, it's not going to be just a cost battle from displacing traditional physical infrastructure. You may want that traditional, physical storage system there for a long time to come, and VSAs might not be truly competitive with a couple of the cases that I illustrated above, where there's serious performance there. VSAs may not be [as robust as] that traditional, physical array. So, you should look at VSAs as an alternative to deliver more functionality, flexibility and capability for your virtual infrastructure and extend storage to be closer to those workloads and give the business more agility.

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