About the product family
The product family is designed to simplify infrastructure in remote offices and branch offices and manage it centrally from a data center. The product family is typically deployed in conjunction with SteelHeads and includes the following components:
• Core—Is deployed in the data center alongside SteelHeads and a storage array. The Core mounts logical unit numbers (LUNs) provisioned for the branch offices from a storage array and manages block transfers between these LUNs and Edges. At the data center, the Core integrates with existing storage systems and SteelHead implementations and connects dedicated LUNs with each Edge at the branch office.
• Edge—Edge refers to the branch component of the product solution. The Edge hosts two distinct functions, or nodes: WAN optimization and Hypervisor platform.
A standalone or high-availability Edge is deployed in the branch and presents the LUNs mounted on the Core at the branch through iSCSI targets. The Edge can also host local LUNs without a Core connection.
The Edge connects to the blockstore, a persistent local cache of storage blocks located inside the Edge itself, and it initially populates the blockstore using the following methods:
• First request—Data is added to the blockstore when first requested. Because the first request is cold, it is subject to standard WAN latency. Subsequent traffic is optimized.
• On-demand prefetch—The system observes block requests, applies heuristics based on these observations to intelligently predict the data most likely to be requested in the near future, and then requests that data from the data center export in advance.
• Policy-based prefetch—Configured policies identify the blocks that are likely to be requested at a given branch office site in advance; the Edge then requests that data from the data center export in advance.