Intelligent Storage Networks
Storage needs a smart network
Intelligence at the network level is the next logical step in the storage
networking evolution. It will provide users the ability to scale and consolidate
their large SAN environments, and utilize previous investments more efficiently.
by Arun Rawtani
Technological advancements and an insatiable demand for storage capacity continue
to drive the rapid evolution of storage products and architectures. In fact,
over the past several years, we have seen storage architecture transform from
DAS to networked storage, creating the foundation for the next phase of the
architectural evolution: Intelligent Storage Networks.
The need for intelligent storage networks is driven by members of the storage
community who aim to ease the management, deployment and consolidation of small
SAN islands into larger SANs. And many storage administrators want a unified
way to replicate and seamlessly migrate information from one storage array to
anothereven if the arrays are from multiple manufacturers.
This need has created a great deal of hype and promise around intelligent storage
networks, but savvy users of technology understand the importance of separating
hype from reality, while they figure out how this next evolution of storage
networking will play out.
Looking back at the DAS model, most storage intelligence was located at the
server or the host. By the early 1990s, however, this model was struggling to
meet increased demands for scalability, manageability, and business continuity.
To address the emerging storage infrastructure needs, new capabilities were
added to intelligent storage arrays, including greater consolidation and scalability
through dramatic increases in storage performance, as well as advanced functionality,
like local and remote data replication. Such technological advancements help
drive the storage networking evolution by solving issues which the older architectures
could not address.
Many companies today, have intelligence distributed at all levels of the storage
hierarchy-in hosts (path management software, HBAs, and device drivers), storage
networks, and storage devices. And now they want to optimize and leverage the
placement of intelligence to maximize the business benefit. The way to do it
is to look at the concept of intelligence at the network level. It is the next
logical step in the storage networking evolution, because it will provide users
with the ability to do something they could never do beforescale and consolidate
their large SAN environments while utilizing previous investments more efficiently.
A wealth of proposed approaches has surfaced, but forward-thinking users have
become increasingly skeptical about overly optimistic promises to take all the
storage functionality that exists today and move it to the network. These approaches
are sub-optimal because in many cases they are purporting to solve problems
that have already been solved. What's more, many of them fail to address the
key issues surrounding large SANs: scalability and consolidation.
The proper guiding principal for distributing intelligence is threefold:
- The intelligence to manage and manipulate data at the Logical Unit Number
(LUN) or volume level should reside close to the storage array.
- The intelligence to perform functions across the whole network should reside
near network switching points.
- Application intelligence should reside in the server while simultaneously
reaching out to all other points of intelligence in the network to ensure
As intelligence starts to move into the network, servers are becoming less aware
of what's happening within the storage environment, allowing much more flexibility
within the SAN infrastructure.
The business value of intelligence
With the relentless growth of data and increasing demands for application availability
and performance at lower costs, customers aren't just asking for intelligent
network applications. They want solutions to suit the scalability and consolidation
needs of their networks. From a customer's perspective, the value resulting
from moving the storage intelligence closer to what it controls can be broken
down into three components:
- An extended choice of application, network and storage platforms at a lower
cost, plus the ability for users to make decisions independently for better
application and enhanced performance.
- Improved capabilities around storage delivery services that will provide
dynamic utilization of network bandwidth and network capabilities.
- Reduced TCO via concentrated points of managementoptimized storage
and offloaded servers.
Free of the limitations and variations of storage hardware architectures, intelligent
storage networks will deliver greater flexibility in storage management and
data availability. Storage administrators, who understand the value of optimized,
intelligent storage networks will be among the first to take command of previously
complex storage infrastructures.
Intelligent network applications
Organizations are seeking to move away from application dependency to data independence.
In order for this to happen, storage must become either application-transparent
or accessible by any application according to hierarchical requirements. To
help achieve this, two basic areas must be added into the network storage presentation.
They are virtualization and data mobility.
Storage presentation refers to the way LUNs are presented to hosts and the ability
to aggregate or split them. A great deal of industry discussion has been generated
on this topic under the heading of virtualization. This capability can be accomplished
today within a single storage array, but the network adds a new layer of virtualization
that will span storage subsystems.
Network-based storage presentation services offer the ability to extend LUN
presentation currently being accomplished within arrays and expand it across
the entire fabric. This means that LUNs can be aggregated across different arrays
to better utilize the storage capacity available in the infrastructure. In addition,
network-based storage presentation makes storage pooling achievable, so that
storage arrays can be virtually combined in a logical fashion and function as
a single pool of storage.
Changing application requirements within companies and across industries mandate
that storage be re-deployed in real-time. As a result, data mobility is required
to insulate applications from storage location and data movement details. Data
mobility can mask and automate the complexities of data migration (regardless
of platform or legacy technology), and enable policy-based data movement. This
matches the vision of many organizations that want to first segregate servers
and storage and then interconnect them via multiple interoperating non-stop
fabrics. Such a strategy forms the foundation of lifecycle data management.
Preparing for the future, today
Although much of this article is focused on future visions, steps can be taken
today to ensure a smooth transition. To begin laying the groundwork for intelligent
storage networking, storage administrators should partner with a company that
has a proven track record for delivering complete solutions while they continue
with their SAN deployments.
They should also continue implementing comprehensive management tools to both
enable successful utilization of intelligent network capabilities, and ultimately,
to ensure that data is automatically deployed to the lowest storage class needed
to meet business requirements for data accessibility.
Arun Rawtani is a Country Manager for Technology Solution Group, based out of
India for EMC Corporation