Quantum StorNext QD7000, Hardware Manual

Page: 121 / 141

Configuration Description
Highest availability
campus configuration
(recommended) This configuration has the greatest redundancy. It is the most stable of the
three configurations.
• Two Fibre Channel switches (for a total of four) at both the primary
site and the secondary site provide for complete failover and
redundancy in the Fibre Channel switches and fabrics, in addition to
all storage array components and hosts.
• A single point of failure does not exist in this configuration, and it is
the recommended configuration.
See Highest availability campus configuration recommended on page
112.
Campus configuration The campus configuration is a lower-cost configuration than the highest
availability campus configuration. Only one Fibre Channel switch at the
primary site and one at the secondary site exist, for a total of two
switches. This configuration essentially allows the minimum required
components to successfully operate between two sites.
• The number of Fibre Channel switches is reduced from four to two
and the number of fabrics from two to one.
• This configuration is redundant for host bus adapters, controllers, and
Synchronous Mirroring ports, but it has a single point of failure for
switches and fabric.
• A switch failure does not usually result in a loss of data, but it does
affect data synchronization until the error is corrected. Therefore, the
highest availability campus configuration is the recommended
configuration, because data synchronization can continue for any
single switch failure.
See
Campus configuration
on page 118.
Intra-site
configuration The intra-site configuration is the lowest-cost configuration of all three
configurations. It is used in environments where a long-distance fabric is
not required because of the close proximity of the hosts and storage
arrays.
• Because the intra-site configuration only has two switches, it is
similar to the campus configuration. However, multiple-switch fabrics
do not exist in this configuration.
• The configuration is redundant for host bus adapters, controllers,
Synchronous Mirroring ports, and switches but is a single point of
failure for the site because all of the equipment can be destroyed by
the same disaster.
• The highest availability campus configuration is the recommended
configuration, because it is fully redundant, which makes disaster
recovery easier.
See
Intra-site configuration
on page 123.
Highest availability campus configuration recommended
Note:
The highest availability campus configuration is the recommended Fibre Channel
configuration for the Synchronous Mirroring feature or the Asynchronous Mirroring feature.
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