SMI-S storage standard breaks supplier lock-in

There is work to be done, but the Storage Management Initiative - Specification (SMI-S) standard promises best-of-breed storage systems, easily provisioned by informed users.

There is work to be done, but the Storage Management Initiative - Specification (SMI-S) standard promises best-of-breed storage systems, easily provisioned by informed users.

In the days before standards for storage management, hardware suppliers devised proprietary application programming interfaces (APIs) and software builders endeavoured to support as many different interfaces as they could.

Management software builders and storage hardware suppliers paired together with bilateral agreements, creating tied-in storage systems where software could not be replaced without replacing the hardware, and hardware upgrades were always sourced from the same supplier. A best-of-breed system was all but impossible. But no longer.

Universal requirement

Although uptake of the Storage Network Industry Association's (SNIA) SMI-S standard for management of heterogenous storage networks has been gradual, it is now all but a universal requirement for storage technology.

"The purpose was to come up with some standard interfaces into storage devices so you could buy supplier x's hardware but use supplier y's software," says Bob Plumridge, technical marketer at Hitachi Data Systems. "Initially progress was slow, what with all the vested interest, but it now covers all the major hardware and software manufacturers.

"If you look at the requests for information and the requests for proposal that we receive from customers and potential customers, almost every one requires us to show compliance with, and conformance to, SMI-S. Also, quite a lot of customers want to see the roadmap and our commitment going forward."

SMI-S version 1.4

Version 1.4 of the standard is due to be announced this month. "Customers are already asking 'If we do this now, will you upgrade the software to comply with version 1.5 when it becomes available?' And we have to commit to that in the contracts," says Pomridge.

SNIA is clearly pleased with how the standard has become established. "Most new devices are based on SMI-S," says Frank Bunn, a director at SNIA Europe. "The enabler was the introduction of storage networking.

"In the old days, most storage was attached directly, so it was pretty clear which device was connected to which service. But in a storage network environment, each device is attached to different applications, and you have a lot more choices of who is speaking with whom. Storage networking was the push to create standardisation.

"SNIA came up with enabling storage networking through standards. Not just sending information from A to B, but managing the infrastructure; what do you have in the network? Managing storage from the reporting side and from the capacity side."

SNIA is now moving up to the data and application layers, says Bunn.

"With so many new capabilities coming up, we are concerned with integrating those new technologies. Integrating security, virtual tape libraries, provisioning, virtualisation tools. The more functionality that comes out in the markets, the more SNIA tries to integrate," he says.

Bunn admits that this is difficult, but he believes it is well worth the effort. Without a standards body, the end-user would suffer.

"The suppliers could not do this individually," he says. "I see good results, since new devices are based on SMI-S and no longer on APIs."

Problems to solve

However, there are still integration and interoperability problems to solve, and even within the standard there are degrees of compliance that might trip the unwary.

Because of this, SMI-S 1.4 includes an interoperability certification defining the level of compliance.

"To make it less complicated for the customer, we define three levels of certification. At level one, the device can be monitored by SMI-S-compliant software. The next level requires active management, and at the third level, the device is able to emit standard notification messages to management software," says Bunn.

The current, rather technical standard is not so easy for customers to understand, admits Bunn, and the change to compliance certification is part of a continual improvement aimed at end-users.

"The goal of SNIA is that customers easily understand what works with what," he says.

This is vital for the longevity of the standard and represents a turning point in the underlying philosophy. SMI-S is no longer an industry document to promote products and interoperability, but has become focused on enlightening storage customers.

Pomridge says, "Customers are asked, 'What do you want these tools to do?' and their answers are reflected in the updated standard and then in the products."

SNIA's SMI-S website >>

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