Nexenta Systems is updating its NexentaStor open source storage software with inline deduplication, which increases the amount of data that can be stored on a server by storing it more efficiently, and support for three popular hypervisors.

NexentaStor 3.0, which is being introduced at CeBit, is the latest version of a storage system that is based on the open source ZFS (Zettabyte File System) technology developed by Sun Microsystems. The company will also release Nexenta Virtual Machine Datacenter (VMDC), a management application based on NexentaStor. The new software will be available by the end of this month.

NexentaStor offers an alternative to proprietary storage systems with an open-source platform that runs on x86 servers used for storage from Nexenta or third-party "white box" system makers. Its latest version offers further advances, including what it says is the first system to support all three major hypervisors in one unified environment, VMDC.

Deduplication reduces the amount of storage capacity taken up by certain kinds of data, by identifying duplicate bits and reducing them down to one instance. Deduplication typically is performed only on backup or replicated copies of data.

NexentaStor 3.0 can perform this task on current information that is going into primary storage, the data that has to be available in real time for use in applications. With some types of data, this allows enterprises to cut down on their need for primary storage, which is often the most expensive type of storage because it requires high speeds. That data reduction can also pay performance benefits itself, by cutting the number of disks in the system and the bits that have to traverse the data centre, said Nexenta CEO Evan Powell.

Turning to the open source NexentaStor for deduplication can free enterprises from reliance on proprietary storage platforms that typically are used for this task, Nexenta said. Those proprietary systems can proliferate if there are multiple storage systems used in a data centre.

NexentaStor is sold primarily through third party "white box" storage platform vendors that integrate it with their hardware. One of the company's major target markets is Internet service providers that want to provide cloud services like those offered by Amazon.com, Powell said.

VMDC 3.0 can now work with the VMware, Citrix Xen and Microsoft Hyper-V virtualisation hypervisors, giving administrators in mixed data centers a single tool to oversee all three environments and manage the storage of data used by all of them. In addition, an administrator can use VMDC to clone a desktop virtual machine that has been pre-configured and is intended for multiple users.

"The most efficient way to clone those desktops is to use the storage array. Don't pound your VMware host, or Xen or Hyper-V, with lots of read-write activity up at that level," Powell said. ZFS can clone a virtual machine into hundreds of copies in just a few minutes, he said.

Using ZFS gives Nexenta an advantage because many enterprises like to work with the open source software, said analyst Terri McClure of Enterprise Strategy Group. For one thing, they can download it for free and try it out, she said.

"You can get a sense of comfort with it before you even pay for it," McClure said. In addition, there is a big developer community following ZFS and users feel less locked down than with major storage vendors' proprietary platforms, even after Sun's acquisition by Oracle, she said. "Once it's open, you can't close it," McClure said.

Support for all three hypervisors in VMDC should make life easier for administrators in shops with multiple virtualization systems, because moving data from one virtualization platform to another is not always straightforward, McClure said.

Adding deduplication for primary data may also help some users, though there are tradeoffs, she said.

"A lot of people are concerned about the performance aspects," McClure said.

Essentially, deduplication involves a tradeoff between CPU cycles (to deduplicate the data and bring it back to its original form) and storage capacity. If a company's applications can't handle delays well, it might not be able to take advantage of deduplication of primary data.

NexentaStor is available free to existing customers and can be downloaded for a free trial at the company's website.