HP Surestore Disk Array 12h and FC60 - Manual (Page 137)

Topologies for Windows NT and Windows 2000 137
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High Availability Topologies
Figure 48 through Figure 51 illustrate high availability topologies. These topologies achieve
the highest level of availability because they have fully redundant hardware data paths to
each disk array. There are no single points of failure in these topologies. These topologies
are more complex and expensive to implement than non-high availability topologies.
Characteristics
• The direct connect topology ( Figure 48 ) achieves high availability by providing
redundant data paths between the host and the disk array, but this configuration also
provides limited distance and connectivity.
• The use of multiple hubs creates redundant data paths between all hosts and all disk
arrays. Multiple hubs also provides greater connectivity, increasing the number of disk
arrays and host that can be interconnected.
• The use of hubs and switches increases the distance that can be achieved between the
host and the Disk Array FC60. The host and hub can be up to 500 meters apart, and the
distance from the hub to the disk arrays can be an additional 500 meters.