Storage consolidation isn't just a matter of hardware
replacement. A sound consolidation strategy also includes software
products that apply a layer of analysis and automation to the
storage infrastructure. For example,
storage resource management (SRM) tools are an important part
of storage consolidation. SRM tools allow storage administrators to
see their storage environment, often across numerous platforms from
a variety of vendors. SRM tools can organize and allocate the
available storage, moving data between storage platforms or tiers
as needed. Finally, SRM tools can offer vital insights into future
trends and growth by tracking the performance and utilization of
storage resources.
Heterogeneity and interface
Even after a storage consolidation project is completed, a
typical enterprise may rely on the availability of numerous storage
systems for redundancy, tiered storage or sheer capacity. Software
can then be applied to "see" and manage that storage. Many storage
systems include their own unique management application, and that
may be a perfectly acceptable path if your organization uses
storage systems from a single vendor. In a multivendor environment,
however, an SRM tool must be able to automatically recognize
diverse storage servers or arrays in the data center. Otherwise,
some storage may remain underutilized. Even worse, a storage
administrator may have to deal with several different tools to
manage all of the available storage. It adds unnecessary complexity
to a process that is intended to simplify storage.
The user interface is an important part of SRM tools, especially
when presenting storage from a variety of storage systems. Most SRM
products tout a "single pane of glass" architecture that
encompasses every storage device and allows users to quickly drill
down for more comprehensive data or detailed information about
specific storage systems.
Many SRM tools use agents installed on each system to be
managed. Agents offer intelligence, often able to acquire more
detailed information from each storage system. However, agents can
also cause a slight performance hit in the production environment.
Agents are also software that will need to be periodically updated
as the SRM software evolves. This in turn adds more management
complexity to the consolidated storage environment. Some SRM
products can use agentless data collection, though the granularity
of collected data may not be quite so fine.
Provisioning and migration
A big part of storage consolidation is the simplification of
storage allocation -- seeing all of your available storage and then
easily assigning storage to applications and users from available
pools of data across the data center. SRM tools often include
provisioning features that allow storage administrators to create,
resize and manage LUNs. Once storage is allocated, data can be
moved between locations or tiers.
Many storage organizations would rather not assign labor to
manage tasks, like provisioning and migration, so automation is an
important part of SRM tools. Provisioning and migration are often
based on sets of user-defined rules. For example, if a
mission-critical application runs short of storage, the SRM tool
can allocate more space or move data to a larger space that had
been prepared for it. Still, automation is not foolproof, and some
amount of hands-on management will be required to ensure that key
applications are running smoothly.
Migration tasks will take time and have an impact on storage
performance. In some cases, the impact is slight, and migration can
be successfully accomplished in the background. However, moving
large quantities of data in short timeframes will invariably affect
storage performance -- potentially impacting service levels and
application availability.
Planning and reporting
Even after storage consolidation has been completed, storage
demands will inevitably continue to grow. For the storage
administrator, this growth has to be managed proactively --
otherwise application availability and performance may become
impaired, forcing the organization to "fight fires" by adding
storage without adequate planning. SRM tools typically include
monitoring features that can report on storage or application
performance. The tools can alert IT administrators when potentially
dangerous performance thresholds are reached, reducing the
possibility of server or application crashes due to low
storage.
SRM tools frequently collect and digest storage utilization and
performance data over time to provide trend analysis and reporting
that can help administrators make proactive purchase decisions
(rather than react to unexpected service problems). By
understanding when and where storage will be needed in the future,
a storage organization can budget accordingly and take advantage of
declining storage hardware costs over time. For example, reliable
trend analysis can allow an organization to purchase larger disks
at a lower cost tomorrow rather than stockpiling a large number of
smaller, more expensive disks today. Predictive reporting can also
help to schedule regular maintenance, repairs and pre-emptive
device replacement.