The Gold Standard
- Article 2 of 2
- Information Unbound, October 2006
The interoperability standards necessary to manage heterogeneous storage environments are starting to crystallise.
Storage area networks are attractive to many enterprises. But there was one overriding problem initially that stopped many from adopting SANs: they didn’t work unless highly skilled, highly expensive SAN consultants and managers made judicious choices in their suppliers, hardware and software. The biggest obstacle was getting different vendors’ equipment to work together, something that was frequently impossible.
The last few years have changed this situation considerably. Through groups such as the Fibre Channel Industry Association and the Storage Networking Industry Association (SNIA), vendors have been able to make connecting SAN hardware together far easier.
This has brought about considerable acquisition-cost benefits.
“The price advantages of being able to acquire kit from multiple vendors have been very enticing,” says Andrew Manners, head of UK storage for HP. “Once people have bought SANs and got them working, they’ve loved them so much they’ve bought four or five. But they haven’t stuck with one vendor because there’s such a cheap entry point and vendors have been doing deals that make it even cheaper.”
In addition, says Jon Pavitt, S&T EMEA storage services director at Unisys, organisations have tended to invest in SANs for individual projects; each project has simply bought a new SAN rather than brave internal politics and the organisational requirements necessary to increase the storage of an existing SAN.
But managing those different pieces of hardware, particularly from a single console, has proven a far greater challenge. In the majority of cases, vendors’ own storage management tools were capable only of managing and monitoring their own equipment using proprietary APIs. Third-party software vendors such as Veritas, now part of Symantec, were able to provide their own storage management tools only by tapping into these numerous APIs.
After several false starts and a long process that started as long ago as 1999, the storage industry has finally been able to agree on a set of management and control standards, SNIA’s Storage Management Initiative Specification (SMI-S), that make interoperability relatively feasible for all vendors.
“SMI-S is the poster child of what SNIA has achieved,” says Matthias Werner of IBM-Switzerland who is a member of the board of SNIA. “It’s where the most benefit is: switches, disks, under a single point of control.”
SMI-S 1.0.2, the latest version of the standards, enables both discovery and some degree of management of storage arrays, switches and hosts without the installation of any software agents. Any hardware that obeys the standard – the majority of new products now shipping – should in theory be manageable by software that understands the standards, using the exact same interface; it can also be monitored, providing detailed information such as temperature, power supplies, fan activity and capacity.
Guy Bunker, chief scientist at Symantec, says this has many benefits for end-users. “Standards offer the customers choice, which is something the hardware vendors are not particularly enthusiastic about. Without standards – and this is something Veritas suffered from – every management product has to understand every product it needs to manage. That discourages innovation from small companies.” Choice means cost-savings; it also allows software vendors to spend less time coping with specific hardware, rather than simply writing to a single standard.
At the moment, Bunker says, the SMI-S standard offers 80% of the functionality needed for most organisations to monitor and control their SANs during their daily operations. The areas where the standards are lacking are in more advanced configuration, such as partitioning and mirroring. For these tasks, recourse to proprietary tools is necessary.
However, Hamish Macarthur, CEO and co-founder of storage analyst firm Macarthur Stroud International, says that that 80% figure hides other issues. “If it’s just about operating, then 80-90% is about right. If you’re looking at in terms of interchange of data, in practice that figure’s not so high.” In particular, standards are of no use when dealing with older hardware: although some vendors offer shims that enable standards-based management of older systems, few do and firmware updates are singularly lacking in most instances. With SANs lasting four years or more in many enterprises, managing them using proprietary tools is usually the only option.
There can also be issues around interoperability. SNIA provides vendors with a certification suite that runs hardware through its paces using the standards; if the hardware responds as required, the vendors can then declare themselves compliant with the latest standards. However, Matthew Brisse, technology strategist at Dell, points out this testing does not show whether the hardware interoperates with real-world software and hardware. And with various different versions of SMS-I available in the real-world, version 1.0.2 being the most common in shipping products (more than 280 have now been certified) and 1.0 available in many just-shipped products, being sure of exactly what a piece of kit should be capable of doing using the standards can be difficult.
Vendors themselves aren’t necessarily helping. Jon Pavitt, who is responsible for Unisys’s storage offering, says that while virtually all vendors have signed up to the standards, they’re “not readily forthcoming” in providing interested parties with details of what hardware they’ve incorporated them into and which versions of the standards. And Nigel Tozer, consulting manager at CA, says the situation is like “shades of the rainbow. Some vendors try to play the game and apply the letter of the standard – just enough to get certified.”
Nevertheless, vendors are adopting the standards in ever-increasing numbers. While Tozer says SNIA could be doing a better job of marketing SMI-S to end-users, an increasing number of RFPs for storage products are requiring SMI-S support, according to Dell’s Brisse. HP’s Manners argues that some standards are better than no standards at all for many organisations, which may not have any real way to manage their SANs: “It’s almost embarrassing. They might have just a single person managing everything in an Excel spreadsheet. Even if you use the most basic elements of discovery available [in SMI-S], that’s better than nothing.” Knowing what versions of firmware are being used in hardware or whether switches need to be upgraded can make all the difference to some organisations.
With industry momentum behind many of the storage standards, many more are planned. Helmut Beck, VP of storage at Fujitsu Siemens Computers, says his company is one of many supporting work in SNIA to develop standardised interfaces between backup storage systems. SMI-S 1.1, which includes support for health and fault management, storage security policy, copy services, policy management, tape libraries, NAS and iSCSI, has been approved and the first group of products are undergoing conformance testing. John Kelly, SNIA’s storage management forum vice chair, says the aim is to consolidate discovery, access, reporting and control features into a single, standard architecture that will establish a foundation for a broader set of management capabilities in the future. The APERI open source framework started in October last year is an industry-wide initiative to create an SMI-S compliant code library for storage management. Extensible Asset Management (XAM) is another SNIA initiative to bring standards to ILM and to create a standard interface between applications and storage, while the multipath management API specification will allow management applications to discover the multipath devices on the current system.
At the moment, only the first steps have been taken with storage standards. Much more effort will be needed before heterogeneous SANs can be completely managed using a single standards-based console. And with storage developments out-running the slower moving standards-creation and ratification processes, the risk is that the 90-10 split in management methods will be permanent, even if the functions involved keep changing. But standards are here and they’re making interoperability much more than a ‘vision’ on a PowerPoint.