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 >>