Managing storage through layers
A look at how Storage Area Management or consolidation of
storage resources is a solution for most storage management challenges. by V.
It is apparent that information storage is regarded highly in enterprises,
as it has turned out to be a very potent tool for remaining competitive in today's
dynamic business environment. This has led to a tremendous explosion in demand
for storage infrastructure. While the importance of storage is undeniably growing,
enterprises are trying hard to transform storage from being seen as a cost component
to that which generates more revenue.
Even though the cost of raw storage is declining by the day, the prevalence
of fiber channel technology in the networked storage era has led to a situation
wherein the cost of manpower required to administer storage is escalating. And
with shrinking IT budgets, storage administrators are finding it increasingly
difficult to meet the demands placed upon them as they try to manage the storage
infrastructure. This has become a deterrent for enterprises in their efforts
towards transforming storage from a cost center to a revenue enabler. Therefore
the primary challenge here is to manage the entire storage architecture, which,
instead of having a small footprint, has a varied and heterogeneous footprint.
This situation puts the performance of business applications, and the business
itself at risk.
SAM (Storage Area Management) or consolidation of storage resources has apparently
evolved as a viable solution for addressing these challenges. However, not all
SAM solutions address the challenges faced by storage administrators.
When considered from a business point of view, SAM is all about quality of service.
In a typical organization, storage administrators have to manually manage the
various elements of storage infrastructure, which may include file systems that
are linked to the database, host bus adopters (HBAs), SAN Fabric switches, the
host server, the storage system itself, and the individual disk drive. The entire
chain from drive to application has to be linked. This is a labor-intensive,
error-prone, and slow process adding, up to delay and higher costs.
However, in today's scenario, businesses that are able to deliver high levels
of service easily will automatically reap benefits, whereas businesses that
cannot will be in trouble. For instance, when an application experiences unexpected
activity, it may not have the storage service that meets its requirement. Consequently,
performance and service deteriorates leading to crashes and downtimes.
While the implementation of a SAM practice seems the most
obvious solution in such a scenario, it is important for administrators to recognize
change and revisit the storage setup. This is because, if they have to effect
change, it has to be done not in months but in a matter of hours. They need
to understand that the implementation of SAM should enable them to manage the
complex SAN infrastructures, storage resource management to address process
issues, and storage provisioning to enable new applications to come online quickly.
In this manner the SAM solution is able to deliver significant TCO improvements
and faster ROI.
However, in order to get the most out of a SAM implementation, it is important
to follow a layered model for storage management; the whole industry is slowly
moving towards this. This type of model relies on building layers within the
storage infrastructure and it is based on the industry-wide standards initiative
called CIM (Common Information Model). This model enables management systems
to recognize and exchange information in a heterogeneous storage environment
that houses different solutions from various vendors.
CIM offers a powerful foundation for cross-platform SAM implementation. Though
the industry has not reached a consensus on the exact definition of the layers,
one model, which has identified four basic management layers, is slowly gaining
prominence. The four layers comprise of reporting, path management, event monitoring
and automation control and they are addressed in succession.
However all these four levels strongly depend upon the base
level, the discovery level, which serves as the building block for this model
to work. At the outset organizations need to understand what storage resources
they have and where it is. This is a very cumbersome process, which earlier
used to comprise of reams of spreadsheets, whiteboards and handwritten notes.
A holistic approach
Ideally a good SAM solution should help administrators get a holistic perspective
of all the elements involved in a storage infrastructure right from the LUN
(Logical Unit Number) all the way to the application. And this has to be viewed
from the application's viewpoint. This helps administrators to discover, track
and locate the existing resources and new resources that are being added into
the storage infrastructure. This apparently provides a very logical platform
that can be used to manage storage in a situation wherein enterprises prefer
to build storage infrastructure by sourcing from different vendors.
Once the storage administrator discovers all the elements within the storage
system, it is important for them to understand how the resources are being used.
This is because, in order that all mission critical applications are functional,
enterprises often resort to having buffer storage to meet unforeseen circumstances.
However, automated reporting and monitoring to determine what additional resources
are needed, and when they are required, comes out as a preferable approach.
From this viewpoint, the SAM solution should be able to optimize the existing
storage resources rather than rely on buffer storage capacity to keep the applications
up and running.
Hence, ideally, while addressing the reporting level in storage management,
the SAM solution should be able to provide an elementary overview across the
entire storage infrastructure, so that they can continuously monitor storage
from LUN to the application. Further, complementing the comprehensive reporting
and monitoring functionality, the SAM solution should be able to provide administrators
with predictive management tools based on historic data so that outages can
be anticipated even before they happen, and corrective actions can be taken.
With such a reporting and monitoring system in place, administrators can optimize
the usage of existing resources, and they can balance loads and shift excess
capacity from one server and application to another. This eliminates the need
for excess and "unnecessary" capacity, while existing "excess"
capacity and bandwidth are available elsewhere within the existing infrastructure.
The next level after the reporting layer has been addressed, is that of path
management. As emphasized earlier, the key to SAM is quality of service, and
this is ensured through good path management. This is because, one of the key
aspects of path management is to monitor the flow of data, from the storage
resource to the application, so as to ensure that the application is receiving
the required levels of service to perform optimally. Besides this, the path
management function also entails provisioning of storage resources depending
on the nature of the requirement. However, it is important to understand that
this cannot happen unless the first two layers of discovery and reporting are
When administrators have all the necessary datathat helps them understand
the storage resources, the ways to optimize storage, and the flow of data that
is required to maintain different levels of service that different applications
demandthey no longer need to struggle to understand the different fault
and problem alerts that come their way. The data helps them exercise greater
control and initiate proactive measures to correct problems that come their
way. This is the third layer in the storage environment wherein the SAM solution
helps administrators troubleshoot problems easily and isolate components that
need correction. This is enabled by the data flow alerts that the SAM solution
sends to them periodically in relation to the applications' service level requirements.
With the three layers in place the last functionality the SAM solution should
offer is to automate the entire management process using a policy-based management
engine. For instance, when a critical application approaches a threshold signaling
that the application will soon run short of storage space, the system acts automatically
and allocates additional storage to that application. By intelligently taking
over an administrator's function, it allows the administrator to be free of
routine tasks so that he can focus on more strategic issues. At this level organizations
can fully leverage on the SAM implementation to improve storage service quality
while reducing costs.
While addressing these layers for management of storage, it is important to
bind together these layers and populate them with the various specialized management
tools coming from different vendors. Therefore, ideally the SAM solution should
be one that leverages on the synergies of an open, management framework and
powerful intelligent storage systems. This requires a collaborative approach
that can be achieved by developing strategic alliances to deliver SAM solutions
that fit more into multi - vendor storage environments and are based on broad
integration with third-party Storage Area Management software.
The writer is Sales Director, S AM Solutions, APIA, Hitachi