With hypervisors a ubiquitous component of nearly every IT deployment, virtual appliances present a compelling alternative to traditional physical appliances by offering a simpler and faster software deployment model. In recent years, many data storage vendors have jumped on the “virtual bandwagon,” offering virtual storage appliances, often referred to as VSAs, and bucking the trend of an industry largely dominated by traditional hardware boxes.

While virtual storage appliances may seem disruptive to the accepted model of an integrated storage array, their attractiveness is largely based on the separation of the high-value I/O software stack from the commodity hardware that underlies them. This software/hardware decoupling enables new levels of deployment flexibility for end-users. For those considering deploying new storage infrastructure, VSAs offer a number of advantages over physical appliances and traditional storage arrays. Five of these advantages include:

1. Zero-U footprint: There’s a certain appeal to deploying data storage systems that consume near-zero dedicated rack and floor space, especially considering traditional data storage systems may often occupy the majority of a data center. Of course, there is a catch — VSAs consume real CPU and memory resources and the actual data storage devices still need to reside somewhere. However, in the case of cloud storage VSAs, the bulk of the storage may reside in an external cloud provider, moving users closer to the near-zero footprint ideal.
2. Fastest time to POC: Ever try setting up a proof of concept (POC) for a new data storage system? Truth is, many storage vendors offer free trials of their physical boxes, but they involve the logistics of transporting the appliance, installing, configuring, powering, cabling, etc.  Even though the POC can start in minutes once the hardware is in place, getting to that point can cost weeks of lead time. Downloading a virtual appliance and installing it in minutes accelerates the trial process dramatically, reducing risk and minimizing time lost waiting.
3. Option to create your own box: It is often challenging to create a “one-size-fits-all” storage appliance. In spite of many traditional storage products offering a multitude of configuration possibilities, sometimes base configurations are too large or maximum configurations are too small — other times, it’s hard to find the appropriate size in between. Virtual storage appliances enable deployment on physical platforms the size that business requirements dictate. Ability to use commodity or best-of-breed data storage devices means any customer can achieve the desired ratio of price, performance and availability. What’s more, many VSAs operate on free hypervisor platforms such as VMware ESXi or Citrix XenServer, minimizing the need for investment in additional hypervisor licenses.
4. Software investment protection: Any IT administrator who has lived through the process of deploying storage arrays and migrating and retiring those arrays just a few short years later can appreciate the value of decoupling the storage software from the hardware that becomes obsolete after a few years. Preserving the existing software stack reduces the downtime and risk of the data storage upgrade and replacement cycle. This advantage becomes even stronger when a VSA is coupled with the nearly infinite storage capacity offered by cloud providers, alleviating the concern of ever running out of capacity, one of the most common reasons for upgrade.
5. Platform mobility and resilience: When it comes to high availability and disaster recovery, traditional storage appliances often mandate additional hardware at both the primary site where the appliance resides and at  secondary or disaster sites. Virtual storage appliances, on the other hand, can leverage existing virtual infrastructure on-premise, off-premise or even in the cloud to increase system availability and resilience. If there is an outage at the primary site, restart the appliance at a secondary site or even in the cloud (for cloud storage VSAs). If the current appliance platform does not meet performance requirements, simply move the appliance to a more powerful and faster platform. With VSAs, there is no longer a need for dedicated redundant hardware on-premise or off-premise.

Given all of the benefits, it’s no wonder the number of VSA offerings on the market is growing. A recent TechTarget article entitled Virtual storage appliance market: Categories, capabilities describes several categories of VSAs: these include shared file storage solutions such as Openfiler, storage optimizers that provide caching and tiering including DataCore SANsymphony and cloud storage gateways such as TwinStrata CloudArray.

Bottom line? There are many benefits to virtual storage appliances and while they don’t necessarily replace physical appliances for every use-case, they offer a wealth of new options and flexibility to IT organizations consuming data storage.