Cisco Cisco MDS 9500 Series Supervisor-2 Module Weißbuch
© 2011 Cisco and/or its affiliates. All rights reserved. This document is Cisco Public Information.
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White Paper
High-Availability Storage Networks with Cisco MDS
9500 Series Multilayer Directors
9500 Series Multilayer Directors
In today’s enterprise environments, high availability is no longer optional. Data
availability is more important than ever as data growth rates continue to accelerate.
As enterprises and applications grow, the ability to increase the size of the associated
data center infrastructure is critical. The advent of a worldwide economy, facilitated by
the Internet, has shifted normal operations from a workday-only to a 24-hour model.
In this “always on” world, more stringent requirements have been placed on high
availability. To keep an enterprise running, data, a company’s most crucial asset,
must be available at all times. Not only can loss of data have catastrophic effects, but
also the inability to access that data can be extremely costly.
availability is more important than ever as data growth rates continue to accelerate.
As enterprises and applications grow, the ability to increase the size of the associated
data center infrastructure is critical. The advent of a worldwide economy, facilitated by
the Internet, has shifted normal operations from a workday-only to a 24-hour model.
In this “always on” world, more stringent requirements have been placed on high
availability. To keep an enterprise running, data, a company’s most crucial asset,
must be available at all times. Not only can loss of data have catastrophic effects, but
also the inability to access that data can be extremely costly.
Although 99 percent uptime can seem like a significant achievement, such a “highly available” environment would
be down for over 83 hours per year. This amount of downtime could have a significant effect on a business of any
size. In designing a highly available solution, the cost of downtime must be considered. A 99 percent uptime
environment could cost a large financial brokerage firm over US$540 million in lost revenue and productivity per
year. Table 1 illustrates the cost of downtime in several industries. Increasing uptime to 99.999 percent reduces
this loss to US$540,000 per year.
Table 1.
Cost of Downtime
Type of Business
Cost per Hour (US$)
Availability (Percentage)
Minimum Downtime Hours per
Year
Year
Financial Brokerage
6.5 million
99.999
5
Credit Card Authorization
2.6 million
99.99
50
Home Shopping
0.1 million
99.9
500
Catalog Sales
0.09 million
99
5000
Airline Reservations
0.09 million
90
50,000
Source: Fibre Channel Industry Association, “Business Continuity When Disaster Strikes,”
http://www.fibrechannel.com/technology/index.master.html
, Horison, Inc.
Achieving 99.999 percent uptime is not always easy. A highly available storage infrastructure is required for
achieving data availability. It includes several components, including Redundant Array of Independent Disks
(RAID) technology, multiple copies of data across a clustered system, clustering over distance, Storage Area
Networks (SANs), and reliable tape backups. Among these component pieces, SAN architecture, the focus of this
paper, enables enterprisewide high-availability configurations that will grow with the organization and protect your
investment in data storage.