FOCUS: STORAGE: Growing Up with Data 

If processing power doubles every 18 months as per

Moore’s law, what about the other aspects of computing? For instance, is there

a law for storage–the most critical part in enterprise computing? If yes, we

havent heard of it. And that’s why storage is the most talked about and least

understood frontier among enterprises. Most learn the hard way, only a crisis

bringing to fore the absence of a robust and comprehensive storage

infrastructure. However, after 9.11, many companies have realized the

criticality of data and are hence putting in place some or the other form of

storage architecture. With more emphasis on infrastructure augmentation, Year

2002 can be called "introspective" for many organizations. As a

result, IT spend in segments like storage remained stable throughout the year.

According to industry estimates, around 35% of any enterprise’s IT budget will

go toward storage-related expenses in 2003.

WHO’S THIS STORY FOR? An IT chief facing growing stacks of data, and struggling to make it available and reliable WHAT DOES IT COVER? n How do I work out storage needs for business apps? n Do we need to upgrade our storage? n Which storage solution..? n How do I consolidate our storage n We're not that big:should I look at NAS and SAN?

Data has become mission critical–in some cases, a lifesaver. To protect

data, CIOs to-day have to evolve a comprehensive storage management policy. And

this policy that they come up with has to be in sync with the organization’s

business goals. A Frost&Sullivan study suggests that a good storage

management policy begins with the definition of storage limits or quotas for the

users, so that everyone across the organization gets proper storage facilities.

This brings in one very critical question–How does one effectively manage

storage? Before searching for answers, lets look at the current state of storage

in most Indian enterprises. Two scenarios emerge here–One is a total lack of

storage awareness... the other, the inability to utilize whatever storage

facilities are available. In order to devise storage architecture, an enterprise

needs to assess two factors that will clearly bring forth the state of storage

bandwidth it has, and will set stage for the next level of maturity. Also, many

organizations fail to utilize the existing storage due to a combination of

reasons and as a result most of them end up using only 60% of the storage space.

This is mainly because most storage space is often attached to servers and,

hence, spare capacities in multiple servers becomes redundant.

Managing storage: Beyond DAS



Once the initial data mapping is done, the crucial part is in identifying

the right kind of storage. Storage buying should be driven by the organization’s

business goals rather than by popular perception. Here enterprises have multiple

options before them and the three major topologies–DAS, NAS, and SAN are still

the most preferred form of storage. However Direct Attached Storage (DAS), the

most common form is slowly loosing its relevance and Network Attached Storage

(NAS) and Storage Area Networks (SAN) are gaining ground. DAS might hold well

for SMEs, but when the storage level exceeds the million-megabyte mark, then it

is time to migrate to a NAS architecture that solves many problems associated

with DAS.

The advantage of NAS is TCO and ease of use. For instance it can be

configured to the existing client set up in minutes due to its plug and play

nature. Any organization aiming for effective server management and file sharing

should go for NAS.

However, since NAS runs on corporate LAN, network congestion happens and

might lead to downtime, but effective network management and bandwidth

allocation will often fix the problem.

NAS-SAN convergence



Traditionally, in a SAN setup, data gets transferred over a storage loop to

the various devices connected with the SAN. The storage media for SAN is based

on the SCSI disks, tape drives, and off late fiber channel interface drives are

being used.

SAN is the most preferred set up that liberates the organization from storage

hassles by providing a highly scalable architecture. Since SAN is based on a

dedicated network, it liberates the LAN and replaces SCSI based interconnected

storage devices with a fiber channel that brings in data transfer speeds to the

tune of 100MB per second and a typical SAN can support up to 128 devices and

with switching technologies this can be scaled to thousands of storage devices.

However such raw power does come with some issues. Managing a SAN is not

easy, particular when an organization has multiple server platforms. But

interoperability issues will no longer hamper SAN adoption because the Storage

Networking Industry Association, in association with 11 major storage vendors,

has created specifications that should be followed in a SAN implementation. The

specifications will enable administrators to use a common set of storage

management tools to manage software and hardware from different vendors.

A recent development in the storage industry is the convergence of NAS and

SAN. Today, NAS is seen as a prelude to SAN implementation. Moreover experts

suggest that the trend will move towards making NAS as the front end and SAN as

the backend of the storage infrastructure. The key driver that is propelling

this convergence is the advantage of NAS in the file-sharing environment,

whereas in a SAN it is not possible. Hence, adding NAS as one of the

functionalities of the SAN makes better sense. The question is–how can

competing architectures converge? They can. For instance, there’s a clear

difference between shared storage and shared files. While SAN shares the storage

resources through a common network, NAS shares files through an IP network. By

uniting the two concepts, files can be accessed through NAS and delivered by

SAN. When these two converge, we have a fourth topology–consolidation or

shared storage.

Shared storage



In simple terms, shared storage is nothing but sharing of contents between

multiple client entities by putting in place a combination of technologies at

work–like NAS, SAN, tape, virtualization etc. The idea behind a shared storage

is to consolidate the gamut of data that runs through the enterprise. For

instance in a robust data-sharing environment, users will be able to share data

irrespective of the platform on which it runs. For example a Windows application

can be shared with a user running UNIX. This seamless integration is the major

advantage of shared storage. Lets sample another scenario–when an enterprise

with a typical DAS architecture has a large number of RAIDS (Redundant Array of

Independent Disks), by consolidation, the number of RAID systems can be narrowed

down to two or three units. The return on this kind of RAID revamp will be the

drastic increase in the per user storage allocation which is between ten to 15

times after consolidation.

Virtualization



Consolidation of storage into a centralized storage repository happens

through virtualization. In a shared environment, storage solutions from multiple

vendors and platforms are involved. A typical virtualization will group all

these multiple storage areas into one single entity. Virtualization sets the

stage for effective data management as it separates space hungry data intensive

apps and low bandwidth applications. This separation makes it possible to run

mission critical applications with relative ease.

According to Aberdeen Group, virtualization eliminates server downtime by

about 30%, since it can be re-configured dynamically.

Storage resource management



Virtualization cannot happen on its own, and the key driver here is storage

resource management (SRM) software. This enables virtualization by taking the

inventory of the physical assets (the number of storage devices) and digital

assets (the volume of data that resides in the devices) and prescribes various

parameters and allocation to the storage administrators in effectively managing

the storage resources. Also with the advent of storage controllers, shared

storage and virtualization has become easier.

As IT usage and automation increases, enterprises are prioritizing storage.

This is because the organization’s entire digital assets reside in the storage

infrastructure. If data has to be accessed from anywhere and at anytime, the

storage architecture a CIO is putting in place makes all the difference. As an

Aberdeen research aptly sums up, " A storage infrastructure has to

fundamentally do three things–store data, move data where needed and make the

previous two manageable. Probably the biggest challenge a CIO has to deal with

is managing these three effectively and arriving at a storage management

infrastructure!

Shrikanth G

3 Steps to Effective Storage Management

Step 1: Taking stock: Determine the

storage needs by mapping the wide-ranging processes by assessing the… 



l Volume and
criticality of data to be backed up and the backup window available



l Volume growth of
data and the growth down the line.



l Distribution and
consumption patterns of data across the enterprise



l Information on
applications and data generated by these applications



l Availability of
network bandwidth (LAN and WAN)



l Availability of
skilled staff and funds  

Step 2: Decision-making: Narrow down on

one or a combination of storage. Options available are:



l Deployment of a
Storage Area Network (SAN) or Network Attached Storage (NAS) or Consolidation.



l Putting in place a
tape device or an automated tape library (in case of high data volumes)



l Selection of
storage software required. This depends on the kind of application, database,

and operating systems the enterprise is running or proposes to implement.

Step 3: Empirical analysis: This is the

crucial part. The CIO has to ascertain the storage solution selected addresses

the following aspects:



l Backup and restore
speed



l Ease of
integration and scalability



l Ease of
installation, configuration, and operation

Source: Industry and market intelligence reports