How much storage does your main disk
array provide right now? How much of that
total storage is being used? Which applications are your biggest
storage consumers? If you don't have an immediate answer to
these questions, you're certainly not alone.
Storage administrators are struggling to identify their storage
resources and utilise those resources to their best potential.
Storage resource management (SRM) tools have
emerged to help administrators understand their evolving storage
landscape, optimise utilisation and performance, automate some
of the most routine and error-prone management processes, and
make informed decisions about future storage expenditures.
"Imagine driving your car without a fuel gauge. You would stop
every day to get gas for fear of running out on a deserted
highway," says Brian Babuneau, analyst at the Enterprise
Strategy Group (ESG) in Milford, Mass. "The same thing happens
in IT. Storage capacity was blindly purchased for fear of
running out of capacity." This article explains the essential
concepts of SRM tools, highlights notable SRM products and
offers a series of helpful acquisition and implementation
guidelines.
Understanding SRM tools
@23991 The deployment of SRM tools is being driven by the need
to know; what storage is available, how it's used, who is using it
and how much it costs. SRM tools analyze the relationship between
storage and the applications using that storage -- monitoring the
capacity in each storage subsystem, the amount allocated to each
application and the capacity actually being utilised by an
application or server. Analytical results are then reported to the
storage administrator who can make informed choices about storage
issues, like utilisation, capacity planning and storage
budgeting.
Underutilised storage capacity can be reallocated to reduce
wasted capacity, and applications that are nearing their capacity
limit can receive additional capacity. This saves capital by
eliminating unneeded storage purchases and heads off potential
performance problems -- and service level violations -- as storage
runs out. By knowing the amount of storage utilised by each user,
an SRM tool can also provide chargeback information that allows the
storage provider, or IT department, to charge for the storage in
use.
Analysts say that SRM tools share common attributes, often
installing agents or other data collection methods on application
and database servers, and using switch and storage system
application programming interfaces (API) to gather information
about the storage environment. Accumulated information is then sent
back to the SRM application where it is stored, processed and
presented.
It's important to note that SRM tools can vary dramatically in
the way they collect information and the details they provide on
capacity and usage. Tools also vary in the interoperability of
servers, databases, operating systems, storage switches and storage
subsystems. However, the use of storage management standards, like
SMI-S, allows for greater heterogeneity by
gathering details from a much wider range of devices. SRM
products are also sometimes categorised by their range of
capabilities. "There are several SRM tools that focus on primary
storage, tracking all aspects of servers through storage,"
Babineau says. "Others track backup resources."
Dealing with limitations
While SRM tools are increasingly popular, the diversity of tools
and their range of capabilities often impose limitations that any
adopter should be aware of. First, analysts warn against SRM
products that only report on storage -- SRM should help an
administrator take action. "IT organisations are constantly
fighting fires and often do not have the luxury of time to sit down
and really do the analysis of an SRM [report]," says Phil Goodwin,
president of Diogenes Analytical Laboratories Inc. in Eire, Colo.
The best SRM tools can identify elements that demand action. For
example, an SRM report might indicate that an Oracle database is
using 200 GB, but it's far more valuable for an administrator to
see that the database only has 50 GB of allocated space remaining,
and an upgrade should be scheduled within the next 30 days.
SRM tools that lack process management should also be avoided.
For example, there can be a significant delay between the time when
a user requires more storage and the point where additional storage
is considered, approved, installed and provisioned. "It is that
process that is the inhibitor of productivity," Goodwin says. "The
better SRM tools are those that do take process management and
process automation into account." Some SRM providers, like
CreekPath Systems and MonoSphere Inc., are automating provisioning
and other tasks.
Performance is another issue with SRM tools. The agents or other
data collection mechanisms at work on servers can potentially
impose performance bottlenecks. This may be particularly important
in busy transactional storage environments, or with other
time-critical storage tasks, such as backups or replication. It's
often worthwhile to evaluate an SRM tool in a lab environment, or
deploy the tool incrementally across an organisation and measure
any impact on performance.
Vendors and product selection
SRM tools can vary in their complexity, capability and cost.
Consequently, storage administrators should carefully evaluate
tools to match the feature set against an organisation's specific
SRM needs. For example, it's easy to implement products that
discover and report on storage and infrastructure. But such tools
are often inadequate for today's enterprise, which depends on
increased automation to reduce direct IT labour for important
tasks, like storage provisioning, backup and recovery, and problem
solving.
"People want tools that can help them take action," Goodwin
says. "It's nice to know that my storage is growing at 40% per
year, but so what?" Today, it is the recommendations, the guidance
and the metrics provided by SRM tools that help users make the most
informed decisions. "It's got to bridge that gap between getting
information and taking action," Goodwin says.
Analysts generally agree that tools should be noninvasive in the
environment. Agentless SRM tools are typically easier to maintain
because there is no concern about agent software updates or
compatibility with host systems. There is also a clear mandate for
storage management standardisation with SMI-S. "ESG suggests
working with vendors that maximise SMI-S standards which limits the
invasive collection of data," Babineau says.
The cost of some SRM tools is usually justified by the resulting
savings in IT labour over time, but Greg Schulz, founder and senior
analyst at the StorageIO Group in Stillwater, Minn., goes even
further, suggesting that SRM benefits may be dramatic enough to
cover acquisition and deployment costs quickly. "You can go out
there and hit some 'low-lying fruit' to, if not totally fund it,
help build a business case for acquiring something more
sophisticated," he says.
SRM tools make a strong showing
Symantec Corp.'s Veritas CommandCentral Storage product offers
visibility and control across heterogeneous storage environments,
touting features, like capacity management, centralised monitoring,
application mapping and active management of storage components. "I
think they have done a very nice job focusing on the 20% of the
functions used 80% of the time," Goodwin says, noting good
deployability, push technology, easy setup and policy configuration
-- all implemented without the assistance of professional
services.
The CA Inc. Vantage product emphasises centralised management of
critical storage resources and capacity planning, along with
extensive reporting and report distribution capabilities. Vantage
supports tape and direct attached storage products in the user's
infrastructure. Goodwin sees Vantage as one of the most capable and
robust SRM tools available, though its complexity can make
deployment difficult. "It tends to be a heavyweight application,
and it does require professional services to implement," Goodwin
says.
Continue to page 2 for more
SRM product discussion and guidelines