Software Defined Storage Networks Virtualizing the SAN with Software Defined Storage Networks Introduction Data Center architects continue to face many challenges as they respond to increasing demands for compute resources and data storage. One of the keys to effectively use limited capital budgets is to invest in flexible and scalable solutions that allow for future growth. These solutions also need to offer rapid deployment and simplified management to reduce operational complexity and expense. Fortunately, there are emerging technologies that now make this possible. Data Centers revolve around networks. In most cases, this means Ethernet, which has become a universal network inside and outside the Data Center. As prices continue to drop, 10Gb Ethernet (10GbE) has become the new standard and 40Gb Ethernet (40GbE) is not far behind. With this quantum leap in performance and bandwidth, there are many cost savings that can be achieved by converging traditional network and storage traffic onto a common infrastructure. With the growth in both compute and network capabilities, virtualization has also become critical to optimize resources and provide greater flexibility. Server virtualization has led the way and is now a mainstream technology. In a similar way, virtualization of the storage network is an innovative technology that reduces deployment time for storage networks and can be further enhanced with 10GbE and 40GbE supported networks. Evolving Network Technologies The growth in server virtualization has led to challenges for network architectures. Before virtualization, application traffic primarily flowed north and south between three tiers of switching that interconnected servers to other servers and storage arrays. Server virtualization has transformed static servers to dynamic virtual machines that require traffic to flow within and between physical servers. Applications are also becoming more complex with components being separated onto different systems, requiring communication across servers. The growth in east-west traffic between servers has strained traditional three-tier switching architectures. Data has to pass through more hops to reach its destination, adding latency and limiting scalability. Data Center network architectures have responded to these influences by collapsing three-tier switching architectures to two tiers. Innovative switching topologies such as spine-leaf and high bandwidth and high density Ethernet switches have lead the way to realizing the benefits of these new Data Center switching architectures. The result is a scalable, high-performance Ethernet fabric. This new scaled fabric has also created several issues. Run away growth of virtual machines, randomness of traffic flows, placement and connection of storage within this new Ethernet fabric are a few of the new challenges. One of the solutions to these new Data Center challenges is next-generation Software Defined Network (SDN) technology, which is particularly beneficial for large deployments and cloud computing. The underlying concept of SDN is management of network services through the abstraction of lower level functionality. This is done by separating the switching control plane (the intelligence), which makes decisions about where traffic is sent, from the data plane, which forwards traffic to the selected destination. Management of network switches is moved from many physical switches to a centralized software controller.
Critical Role of Storage Networks An important part of an optimum network strategy involves storage. The benefits of a Storage Area Network (SAN) have been understood and realized for many years. SANs provide a centralized data repository that is available to servers and applications throughout the Data Center. Advancements in storage technologies insure maximum availability and centrally managed backup procedures minimize the possibility of data loss. Storage networks are also critical to virtualized servers, allowing virtual machines to be migrated for optimum use of server resources and maximum uptime while maintaining seamless access to needed data stores and files. The growth in server CPU speed and memory capacity has led to higher virtualization ratios and the virtualization of high-demand applications that are more dependent on east-west routing between servers as opposed to north-south data flow. As a result, there is a parallel requirement for increased network performance. While Fibre Channel based SANs have transitioned to 4Gb, 8Gb and 16Gb generations, storage networks based on Ethernet are the high-performance leaders with 10GbE as the base line and 40GbE becoming more attractive with reduced prices and greater availability. While the benefits of a traditional storage network are compelling, there are associated challenges. Fibre Channel products are relatively expensive compared to standard Ethernet products. This is especially true with specialized Fibre Channel switches that are costly and lack flexibility. Fibre Channel management also requires specialized skills and tools that make it difficult to use in non-enterprise Data Centers. Fibre Channel based SANs require a separate network and are based on director class switching (end-of-row) that includes additional extenders as well as expensive cabling and adapters to interconnect the devices. The ideal solution should preserve the benefits of traditional Fibre Channel storage and leverage the benefits of high-performance Ethernet networks. As shown in Figure 1, key elements include: Communicate with servers and storage arrays to provide global SAN services such as name services and zoning Maintain SAN best practices with redundant network paths supported by global path management Implement a heightened network security model Use enhanced Ethernet switch capabilities that are available from many vendors Figure 1 Traditional Fibre Channel with Ethernet network.
Software Defined Storage Network A new technology from Jeda Networks, the Software Defined Storage Network (SDSN), addresses these challenges and requirements with an innovative application of SDN to storage networks. Similar to the way SDN virtualizes Ethernet networks, SDSN provides a software-based solution for converged storage networks that utilizes Fibre Channel over Ethernet (FCoE). FCoE is based on specifications that were part of the International Committee for Information Technology Standards (INCITS) T11 FC BB-5 standard published in 2009. They define a technology for encapsulating Fibre Channel frames into Ethernet, allowing storage and network traffic to be supported on a common infrastructure. They also include Data Center Bridging (DCB) standards that enable lossless Ethernet and priority flow control to optimize performance. Although FCoE can provide compelling benefits, the adoption rate has been slow. Many of the key concerns relate to FCoE switches that have a high cost relative to standard 10GbE switches and require management to be done individually on each switch. Jeda Networks SDSN technology addresses these concerns and provides additional added benefits. Instead of using a control plane that is embedded in an expensive FCoE switch, the control plane is extracted in a virtual machine called the Fabric Network Control (FNC) that can be resident on any virtualized server. This provides several key advantages: More Vendor Choice: FCoE devices can be deployed with qualified Data Center Ethernet switches that support DCB standards with full support for lossless Ethernet and priority flow control. This provides new switch options vs. traditional FCoE switches that are only available from a limited number of vendors. The result can be savings of up to 80% on capital infrastructure costs. Converged SAN/LAN Management: FNC software allows convergence of LAN and SAN network management onto a single console with a single point of management for the storage overlay. Standards-Based: All of the required Fibre Channel services are provided by the FNC software including Name Server, State Change Notification and Zoning. The FNC software is licensed by the number of FCoE devices, initiators and targets in a network. The efficiency of this model is realized by eliminating any extra costs associated with managing devices that are not present. Scalability: The SDSN controller resides on a server so CPU and memory resources can be added as needed. This results in optimum performance and scalability for the smallest to the largest virtualized SANs. Speed Agnostic: FNC software based storage networks have the potential for greater bandwidth vs. traditional Fibre Channel. This includes the use of consolidating 10GbE networked devices and further aggregating through the support of 40GbE and 100GbE devices and backbones. Ease of Management: Many management and trouble-shooting issues can be resolved using standard management tools that are familiar to network administrators. This helps the SAN and network management teams provide full support for the converged network and storage devices.
How Do SDSNs Work? The heart of a Jeda Networks SDSN solution is the FNC, a software virtual appliance that runs in a virtual machine on a virtualized server. Jeda Networks FNC software is designed to run on a VMware ESXi host, other hypervisors will be added in the future. CPU and memory resources can be assigned to the virtual appliance using standard VMware vcenter Server management tools. The virtual appliance supports global SAN services and communicates with all SAN devices in the network. Data traffic is based on the ANSI standard BB5 and BB6 FCoE protocols with each server in the network having a standards-compliant Converged Network Adapter (CNA) and each storage array being FCoE compliant (most storage arrays today have the option to support Fibre Channel, iscsi or FCoE). As shown in the following figure, the virtual appliance communicates with the switches in the Ethernet fabric to provide a software network overlay, which includes adding entries into the switch access control lists (ACLs). The software network overlay is switch-specific and optimized for each supported switch. The FNC virtual software appliance also communicates with servers and storage arrays using the FCoE control plane to fully enable storage data transfer, which occurs in the switch data plane. Initiator and Target Discovery Storage Network Configuration Ethernet Fabric Servers Storage Data Transfer FCoE Control Plane Software Network Definition FCoE Data Plane Storage Arrays Figure 2 SDSN overview. Although a detailed description of installing and managing a Jeda Networks SDSN solution is beyond the scope of this technical brief, several key points will be highlighted. The first step in SDSN configuration is adding Ethernet FCoE fabrics using a simple command wizard. Two fabrics are typically added to provide redundancy. The next steps are adding switches to the fabric and creating zones. Storage networks are identified by a unique IEEE 8-byte Worldwide Port Name (WWPN) that is separate from MAC or IP addresses. FCoE devices are also placed into zones, and zones are then added to a zone set.
Figure 3 shows all of the components, which are then activated. The resulting SDSN fabric can be managed through existing Ethernet management tools. Ethernet Fabric A ZONE 1 Server 1 Initiator FNC VM Storage Array Target ZONE 2 EthernetFabric B Zone set SDSN contains: ZONE 1 ZONE 2 Figure 3 Storage network topology. As illustrated in Figure 4, an SDSN exports a logical and simplified representation of the physical network. The abstraction allows for more choice in Ethernet switch vendors as well as automation of network configuration. The FNC automates configuration of the Ethernet switches to connect initiators and targets in secure zones. FCoE/Fibre Channel Zones Server 1/Array 1 Server 2/Array 1 Server 3/Array 1 Server 1/Array 2 Server 2/Array 2 Ethernet Switch FNC Virtual Appliance FCoE Server 3 FCoE Server 1 FCoE Server 2 FCoE Storage Array 1 FCoE Storage Array 2 Figure 4 Logical representation of the physical network.
With activation of the fabric and switch configuration, an SDSN can be managed with existing LAN management tools. Figure 5 shows use of the LAN SNMP tool Wireshark to monitor the network Ethernet switches as well as providing the link status and link statistics between the switches and the storage Initiators and targets. Ethernet Switch Storage Array Figure 5 SDSN monitoring with open source tools (SNMP Manager/Wireshark). Conclusion Jeda Networks SDSN technology is an innovative, virtualized and scalable solution that is transforming the way applications connect with network storage. It s the next generation in the long evolution of SAN architectures. A Jeda Networks SDSN reduces costs and simplifies management to bring the benefits of high-performance network storage to cloud, enterprise and SMB environments. Key Jeda SDSN advantages include: Enables a true one-wire Data Center based on standard Ethernet switches. Replaces the need for expensive and proprietary SAN equipment, eliminating vendor lock-in and reducing capital expenditures Simplifies deployments while maximizing network availability and scalability Reduces management time and cost with storage network administration that is completely software based and uses well understood virtualization platforms and standards-based CNAs Provides a solution that is network speed agnostic (10GbE, 40GbE, 100GbE) and outperforms 8Gb/16Gb Fibre Channel based storage networks 2014 Jeda Networks, Inc. All Rights Reserved. No portions of this document may be reproduced without prior written consent of Jeda Networks, Inc. Specifications are subject to change without notice. Jeda Networks, and the Jeda logo, SDSN, and FCoE Network Controller are trademarks or registered trademarks of Jeda Networks, Inc. in the United States and/or other countries. All other brands or products are trademarks or registered trademarks of their respective holders and should be treated as such. Jeda Networks, Inc. 4400 MacArthur Blvd. Newport Beach, CA 92660 USA, www.jedanetworks.com 140226