DAS infrastructure couldn't keep pace with its growing
customer base. It wanted a platform that would let it
reduce cycle time for loan processing and beat the competition
in terms of online response times. A SAN was the logical
solution for this. by Prashant L. Rao
A century after it commenced
operations in the country, Citigroup provides banking
and investment services to two million customers—both
consumer and corporate. The company is also one of India's
top credit card issuers with close to three million
Operations team at Citibank India manages the company's
financial applications and related transactions. Its
mission extends to managing the bank's website (http://citibank.co.in)
that lets its Indian customers apply for loans, open
accounts, view statements, and pay their bills.
Citibank India provides banking and investment
services to two million customersboth consumer
and corporate. The company is also one of India's
top credit card issuers with close to three million
The company needed to build a storage infrastructure
that would cost-effectively manage its growing
storage requirements, improve network performance,
reduce management costs and improve system availability.
The existing DAS set-up couldn't scale adequately
and was becoming increasingly difficult to manage.
A Storage Area Network (SAN) based on 2 Gbps Brocade
SilkWorm 3800 fabric switches and 1 Gbps SilkWorm
2800 fabric switches, connecting a network of
Sun and HP servers with an EMC Symmetrix 8530
disk array and a StorageTek L7000 tape library.
Competitive advantage as a result of 20 to 30
percent faster back-end processing. End-to-end
network fault tolerance has increased system availability.
Hardware consolidation and centralised SAN management
have led to improved resource utilization. Cost-effective
scalability helps handle Citibank's rapid business
growth. Faster applications lead to faster business
The need for
pioneered the electronic banking industry in the country
by introducing e-banking and its website offers a bouquet
of services ranging from online statements of bank accounts
or credit card history to loan applications and online
bill payment. With the goal of leading the industry
in response time on its Internet banking site, and for
credit card transaction processing at merchant locations,
Citibank India knew that it would need to transform
its IT infrastructure. In particular, the company wanted
to implement larger servers, additional storage capacity
and a more reliable network to streamline application
Over time, the
technology team realised that its traditional Direct
Attached Storage (DAS) environment was not flexible
enough to keep pace with the company's anticipated business
growth. In the existing DAS environment, each host server
was directly attached to a storage device and data on
that device could only be accessed via the LAN through
the operating system of the attached server. As the
bank's demand for data storage grew, it was forced to
add more server-storage pairs, each with its own operating
system dependent backup and recovery software.
Vice President of Technology Operations at Citibank
India (Consumer Bank) says, "In the next year we plan
to open at least 100 more bank branches and expect an
almost 200 to 300 percent increase in transaction volume.
We are growing very fast, so network scalability is
that an IT project is only as good as the technology
that powers it. Sarkar collaborated with Citibank's
local IT partner, EMC India, and designed the SAN. "When
it comes to SAN infrastructure we looked for a vendor
who could provide quality products, advance features,
interoperability with any server or storage vendor;
better ROI and ease of implementation and management,"
To meet its new
business objectives, Citibank India decided to migrate
from a DAS environment to a high-performance, scalable
SAN. The rollout began in April/May of 2002 and was
finished by August that year. A pilot was done to test
the functionality and capacity. The testing was satisfactory
and the stress test revealed the capacity of the switches.
EMC conducted the training with consultant help from
Today, the SAN
environment features a heterogeneous network of Sun
and HP servers. The server pool includes a Sun Fire
15000 server, two HP-UX servers, and several Tru64 Unix
servers. Citibank India's storage set-up is made up
of an EMC Symmetrix 8530 disk array and a StorageTek
L7000 tape library—the company has a mammoth storage
capacity of 14 terabytes. The core of the SAN consists
of the SAN fabric—a redundant dual-fabric configuration
of Brocade SilkWorm Fibre Channel switches connects
all the servers and storage devices. The switches include
two 2 Gbps 16-port SilkWorm 3800 switches and two 1
Gbps 16-port SilkWorm 2800 switches.
a SAN, Citibank India has derived some immediate advantages,
not the least of which is a 10 to 20 percent improvement
in performance while processing online customer transactions.
The bank has also seen a 20 to 30 percent improvement
in handling back-end processing jobs. These performance
gains are directly impacting the company's market competitiveness
and its bottom line for the better.
Sarkar says, "Reducing
cycle time for loan processing and beating the competition
in terms of online response times will definitely help
us grow our business volume. We have also seen performance
gains for credit card transactions at merchant locations.
If the merchants are able to process our credit cards
faster on Citibank terminals, which saves us from paying
service fees to other banks. In fact, we should even
be able to process other banks' credit transactions,
so we can charge them service fees to increase our revenues."
Through the SAN,
Citibank India has succeeded in consolidating its server
and storage devices thereby boosting resource utilization.
That said, the bank hasn't wasted its old infrastructure.
Its existing DAS devices displaced by the larger servers
and storage systems have already been re-deployed to
a development environment. Not only has the SAN implementation
led to improvements in scalability, performance, and
resource utilisation, it has also addressed the objective
of increasing system availability, which is a must for
providing a foundation for end-to-end fault-tolerance
throughout the network.
include skipping a database generation. Sarkar says,
"The SAN has definitely increased our ability to keep
applications running in the event of a failure. We also
are using Oracle 9i Real Applications Cluster (RAC),
which makes data movement from one domain to another
transparent. Initially, our plan was to migrate from
Oracle 7 to Oracle 8, but the SAN enabled us to move
to Oracle 9i RAC and all its advanced availability features."
"We have seen excellent
stability, even though it's a very new environment,"
Sarkar adds. "The SAN has been a very cost-effective
way to help our business continue to scale up."
which are troublesome, have been dramatically shortened.
"Before the SAN implementation, we used to backup a
10-terabyte database every other day. With the SAN,
we have seen almost a 100 percent improvement in our
backup windows, so we can now back up most of our databases
on a daily basis," concludes Sarkar.
to the SAN will depend on Citibank India's capacity
planning requirements needed to support its business
growth that is expected to be in the range of 30 to
40 percent in 2003. The company plans to extend the
SAN for disaster recovery.
Prashant L. Rao. can
be reached at firstname.lastname@example.org