Candera controller tackles SAN problems

By Heidi Biggar

Milpitas, CA-based start-up Candera claims that users can address key storage area network (SAN) issues (e.g., interoperability, capacity utilization, provisioning, etc.) with a pair of its SCE 510 network storage controllers. The in-band controllers support heterogeneous devices and provide storage virtualization and centralized SAN management.

The idea of tackling issues like management and capacity utilization/provisioning from a network device is not new, but what is unique—at least for now—is the controller-based approach Candera takes.

"There's a lot of competition in this space from software vendors like FalconStor and switch vendors that will add virtualization services on their platforms; however, there are a few differentiators that could help Candera compete," says Nancy Marrone-Hurley, a senior analyst with the Enterprise Storage Group consulting firm.

Brocade, Cisco, and McData have announced plans to ship switches that will support storage services that have historically run on host servers or disk arrays. Product delivery may come by year-end, although analysts say mid- to late 2004 is more likely.

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Moving services and functions into the network—on a switch or a controller—has a number of potential benefits. Proponents claim that SANs will become easier to manage, scale, and implement—and they may even become less expensive.

Marrone-Hurley says that because Candera's controller is a dedicated appliance it should have a performance edge over software-based solutions that run on off-the-shelf servers.

Compared to switch-based alternatives, the fact that the controller terminates the data path is a key differentiator, according to Marrone-Hurley, because it enables users to share data across multiple SAN islands without any security or zoning fallout.

Consolidating SAN islands enables SAN administrators to recover unused capacity.
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According to Marrone-Hurley, if a user were to use a switch-based product to share all available SAN resources (e.g., disk capacity) across multiple SAN islands, there would be zoning and security issues. However, because the Candera controller sits in the "middle" of each SAN and terminates the data path, there are no such issues, which means data can be easily shared among disparate SANs, she explains.

"Hosts see the SCE 510 as a RAID controller and the storage devices see the controllers as hosts, which makes it very easy to deploy," according to Stephen Terlizzi, Candera's vice president of marketing and business development.

SAN storage that has been attached to the controller is pooled, or virtualized. All unused storage is made available to hosts that are part of the network (see figure).

Storage capacity can be added to the pool and unused capacity can be sliced into varying-size LUNs as needed and dynamically provisioned to hosts through a single-step provisioning process using a Java-based GUI. The interface provides a view of, and reports on, all servers and storage in the SAN, as well as all used/unused capacity.

Users can also build "storage profiles" to set guidelines for the type of storage (e.g., enterprise-class, mid-tier, ATA) hosts can have access to, recognizing that not all applications require the same level of storage. The controller provisions storage based on these profiles.

In beta testing, Candera claims that customers saw a 30% improvement in storage utilization and were able to lower tiered storage costs by 25% by making better use of existing resources.

The 2U SCE 510 controllers are sold in two-node active-active clustered pairs. Each controller has eight 2Gbps Fibre Channel ports (four host and four storage ports), with scalable support for up to 48 host, 24 RAID, and 128 JBOD connections. The unit is priced from $120,000.

This article was originally published on October 01, 2003