Although most vendors make a considerable effort to develop or license the technology for communicating with other vendors’ products, the wide variety of products on the market, the speed at which these new products are appearing, and the continuous development of new technologies make it extremely difficult for any platform to support everything. On the other hand, customers are telling the vendors in no uncertain terms that they won’t buy products that can’t manage a heterogeneous environment.
“Many customers today are already doing some form of storage management and virtualization,” says Veritas’s Fairbanks. “In talking to our customers about the future, we’ve found that they are looking for robust storage management and virtualization features that enable common storage IT practices across multiple OS and hardware storage platforms.”
That’s why virtually every vendor in the storage industry, major and minor, is a member of the Storage Networking Industry Association (SNIA), which has been working to improve interoperability by drafting the SMI-S specification (see “Toward a Universal Standard”). The first version covers communications between devices on a SAN, as well as communications between a management application and the devices. Forthcoming versions already in development address topics beyond the SAN hardware itself, including management of data services such as backups, replication, snapshots, and ILM.
SMI-S is not a device specification. Instead, it covers how devices and applications on the SAN communicate with each other. It uses two existing technologies: CIM (the Common Information Model) -- originally developed for LAN technologies — and XML to pass data between devices. Because SMI-S is extensible and continues to evolve, it will be able to address future needs of SAN management as necessary.
Struggling With SMI-S
“SMI-S won’t solve storage-management problems overnight,” says Jeff Hornung, vice president of the gateway business unit at Network Appliance, “but it should eventually allow a broad scope of storage management from a single platform. The more things that are adopted into the SMI-S spec, the better things will get for everyone -- including us -- though we may have to work harder to innovate.”
Tom Rose, vice president of marketing for AppIQ, agrees. “SMI-S is like SNMP in the early LAN days -- it will take time to get everyone on board, but we’re seeing more companies get on board all the time. SMI-S has won in the sense that 100 percent of vendors have committed to it, though less than 70 percent are currently supporting it.”
It will be a while before SMI-S lives up to its potential. As Jack McDonnell, chairman and CEO of Crosswalk says, “The lack of maturity of the SMI-S spec and the dearth of available SMI-S capability to date makes integrating with most applications a challenge, due to the necessity to use published APIs to communicate with each different application.”
McDonnell says that so far, even when SMI-S is supported by a device or application, all the needed information isn’t necessarily available. Not every field may be fully populated, or data may be in the wrong fields. He estimates that currently half of the information needed to successfully manage storage devices comes from SMI-S and CIM. The rest of the data is gathered using device and application APIs or SNMP.