Designing Storage Area Networks: A Practical Reference for Implementing Fibre Channel and IP SANs (2nd Edition)

Along with interoperability, management of storage networks has trailed behind the introduction of functional SAN solutions. Because SAN management includes both transport and placement of storage data, it is considerably more difficult to simplify deployment and operation of storage networks than to streamline traditional network management. The proliferation of IP SANs will make storage transport management more accessible because of the maturity of tools for IP network monitoring, configuration, and traffic shaping. Merging transport management with storage LUN, volume, capacity utilization, and backup management is more problematic. The comprehensive framework offered by CIM/WBEM as an industry standard approach will be several years in the making, but it holds more promise than the current effort by large vendors to create management Band-Aids by swapping their proprietary storage APIs. Customers who settle for these schemes will always be vulnerable to the politics of vendor alliances as agreements are made and broken by competitive interests.

The targets of management initiatives are typically the sundry hardware components that compose the SAN. Host bus adapters, SAN switches, hubs, bridges, tape subsystems, and disk arrays are all sources of management data. Instead of having separate management utilities for each device to monitor connectivity, errors, utilization, and other statistics, a common management framework is possible as long as all devices present management data in a uniform format. As with any upper-layer application, the management platforms that solicit and consolidate standards-compliant data from end devices are not themselves subject to application-level standards. There is no requirement, then, that management frameworks must play well together or must avoid stomping on each other when multiple frameworks are monitoring the same infrastructure. This is a problem for volume management when, for example, disk-based volume management and host-based volume management are inadvertently turned on at the same time.

One argument against standardization of SAN management is that it must be crafted around the lowest common denominator of product capabilities. Feature-rich proprietary APIs are stripped down to their bare essentials for the sake of standards conformance. SNMP network management addressed this issue long ago by allowing vendor-specific MIBs to coexist with industry-standard MIBs. The customer then has the option of leveraging richer functionality in specific products if desired, while still having uniform monitoring and management capabilities across all products. The operative words here are "has an option," because it should be up to the customer, and not vendors, to determine what level of management is appropriate for the customer's configuration.

As with standardization and interoperability, customers who take a more active part in the industry discussions on storage management can help to define what is really needed and can accelerate delivery of useful management products to market. In a room full of noisy vendors, each of whom has vocal opinions about what a technology should do, things go amazingly quiet when a customer speaks up.