Storage management will take a major step forward this year when the Storage Networking Industry Association (SNIA) completes work on the first version of the Storage Management Interface Specification, or SMI-S, a specification for a standardized interface for storage management applications.
Managing multi-vendor Storage Area Networks (SANs) is a key concern for end-users and integrators alike. It typically requires the use of a several applications from multiple vendors. The applications are typically uncoordinated and unable to work together to deliver the functionality, distribution, security, and reliability to ensure the delivery of increased business efficiency.
The SMI-S Architecture
As shown in the illustration, the Storage Management Interface Specification architecture will provide for:
Interconnect Independence: SMI-S specifies a protocol stack consisting of CIM-XML (object descriptions and management actions) over HTTP (session), over TCP (transport), over IP (interconnect). The ubiquity of the lower layers of this stack make it possible to manage components using in-band communications, out-of-band communications, or a mix of the two.
Multi-Layer Resource Management: Virtualization and other services may be provided by server-based volume managers, by switches, RAID systems, and NAS systems.
Accommodation of Legacy Systems: SMI-S incorporates mechanisms for standards-based management of legacy devices with proprietary interfaces. Devices and subsystems can be integrated into an SMI-S network using software agents (one per device) or CIM object managers (CIMOMs—one or multiple devices). Agents and object managers bridge to proprietary device management models and protocols and those of the SMIS.
Policy-Based Management: As higher-level abstractions than models developed specifically for individual components, SMI-S Object Models are applicable across entire classes of devices. Common abstractions make it feasible for software developers to implement policy -based management for entire storage networks.
The technology underlying the SMI-S
As a SAN management interface, the SMI–S will provide four key features:
• A common interoperable and extensible management transport
SMI-S is the unifying factor between objects that must be managed in a storage network and the tools used to manage them. SMI-S is based on the Web Based Enterprise Management (WBEM) architecture and the Common Information Model (CIM) as pioneered by the Distributed Management Task Force (DMTF). The use of the CIM-XML over HTTP standard, an object independent management protocol, allows vendors to dynamically extend the features and functions of their products without redesign of the management transport.
• A complete, unified, and rigidly specified object model
The control of Logical Units (LUNs) and Zones is provided for in the context of a Storage Area Network (SAN). Developers of components of a SAN, such as Switches, Host Bus Adaptors (HBA), and storage devices, can turn to one document to understand how to create their management interfaces.
• An automated discovery system
SMI-S compliant products will automatically announce their presence and capabilities to other constituents. Combined with the automated discovery systems in WBEM to support object model extension, this feature allows for greatly simplified plug-and-play SAN management.
• Resource Locking
A lock manager allows SMI-S compliant management applications from multiple vendors to coexist in the same SAN and share the management of resources without conflict.
New areas for the adoption of storage networks
SMI-S will shift the industry development model relieving vendors of the tedious task of integrating incompatible and ‘feature thin” management interfaces, allowing them to focus on building management engines that reduce the cost and extend functionality. Device vendors will be spared the expense of “pushing” management interface functionality across an industry of management applications developers and empowered to build new features and functions into subsystems.
With steady execution by developers in SNIA’s technical workgroups, and adoption by the industry at large, the SMI-S interface has become a robust industry standard for storage management and will lead to easier, faster deployment of local or wide-area storage networks, accelerated adoption of policy-based storage management frameworks, and ultimately result in improved customer return on investment (ROI) and increased user confidence.
Shankar Subramanian is the Asia-Pacific services manager for Brocade Communications Systems.