Virtual storage appliances can be the key to accessing the high-end features of server virtualization without a high-end storage array. A virtual storage appliance runs on a virtual machine and aggregates unused direct-attached capacity into storage pools, creating what looks like shared storage. In virtualized environments, shared storage is typically what grants access to features such as high availability or redundancy, but it requires the use of costly additional hardware. Virtual storage appliances can achieve those same features, but without the hardware requirement.
Virtual storage appliances (VSAs) vary, scaling for different needs and use cases. They range from Hewlett-Packard's StoreVirtual VSA for SMBs to NetApp's Data Ontap Edge VSA for remote offices to VMware's vSphere Storage Appliance that is limited to three servers.
In the following guide, find out how VSAs augment existing storage, for what specific purposes they can be used and what vendors have been doing in recent months to improve their products.
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Shared storage in a virtual environment is what grants access to beneficial features and typically requires a dedicated, costly storage array. But virtual storage appliances present a less expensive alternative by allowing a virtual machine to connect to the RAID controller, making storage available to multiple hosts. In this video, DeepStorage.net founder Howard Marks explains how VSAs are implemented into a virtual environment and exemplifies how one appliance used primarily for snapshots can improve performance.
As more vendors have developed products for virtual storage appliances, the market has become more defined. VSAs are now used for specific purposes and can be categorized into several different types. At the lowest level, they provide shared storage. Some might offer storage features such as deduplication or thin provisioning, while others are used primarily for caching or providing access to cloud storage. This article outlines the various categories of VSAs and how they achieve their respective functions.
How to optimize virtual storage appliances
Today's virtual storage appliances include products that are starting to act like -- and can even be a possible alternative to -- physical storage systems. The versatility of recent VSAs to act as backup or primary storage, or to help simplify storage management, makes them more appealing to businesses of all sizes, as opposed to only SMBs. In this podcast, Jeff Boles, a senior analyst at Taneja Group, explains some of the latest innovations in VSAs and why they are gaining broader appeal.
NetApp offers virtual storage appliances with Data Ontap Edge
HP rebrands, improves its virtual storage appliance
VAAI supported in Tintri storage appliance
Analyst: VSphere VSA will replace midrange arrays
One common use for a virtual storage appliance is as a backup option. These appliances typically act as cloud storage gateways, which present cloud storage to a virtual environment as a shared storage device. With today's advanced virtual appliances, these cloud storage gateways often offer the same features as VSAs used as primary storage. In this podcast, Windows expert Brien Posey explains how to differentiate virtual appliances used for backup from those used as primary storage.
Learn more about virtual storage appliances from these related links
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VSphere 5 features include VMware storage appliance
HP launches a virtual SAN appliance for Hyper-V
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VSphere Storage Appliance could lower VDI costs