VMware Expands Software-Defined Storage With New VMware Virtual SAN (VSAN)


"This is an incredibly diverse impact on customers' ability to manage storage," Farronato said. "Today, there are a lot of silos. Performance is unpredictable. And cost is out of control because of a need to overprovision."

VMware is tying its software-defined strategy to vSphere because vSphere has an inherent knowledge of all applications running on the platform, Farronato said. VSphere also has a global view of the entire infrastructure, and is hardware-agnostic, he said.

While VMware already has multiple storage technologies in its stable, it is introducing several new technologies that add software-defined storage capabilities to customers' existing infrastructures.

Foremost among them is VMware Virtual SAN, or VSAN. VSAN redefines the hypervisor to let vSphere cluster the SSDs and hard drives from three to eight servers into a shared storage pool. Each server can support up to five disk groups consisting of an SSD and up to seven hard drives, providing a capacity of over a half-petabyte on a single VSAN cluster.

Farronato said VSAN gives customers a scale-out architecture with built-in SSD caching based on those pooled storage resources.

"The great thing is, it provides for fully automated provisioning," he said. "Out of the box, a customer can specify policies to a virtual machine, then self-tune the provisioning in response to changes in their workloads. This gives the ability to have a scale-out storage environment."

With VSAN, virtual machines are provisioned on the fly, each potentially with its own policies, Farronato said. The virtual machines can be provisioned against any storage in the pool, with storage dynamically scalable by the addition of nodes or capacity.

Storage provisioned with VSAN is resilient, with mirroring at the read and write levels, replication on the storage side and high availability capability that allows a failed virtual machine to automatically restart on a different host, he said.

While VSAN virtualizes servers' storage resources, performance is quite high, Farronato said. Write-intensive workloads with 4-KB random writes perform at 14,000 IOPS per node, while read-intensive workloads with 4-KB random reads perform at 22,000 IOPS per node. A typical mixture of 70 percent reads and 30 percent writes provides performance of 100,000 IOPS in an 8-node cluster, he said.

VSAN has been in private beta since the first quarter of 2013, and in the third quarter will move to public beta, Farronato said. He did not say when it would be in general availability.

NEXT: VSAN Does Some Array Functions, But Is Not An Array

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