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Example 3 shows how you can cascade two A54812-SW switches to increase the number of devices in the SAS
domain. As in Example 1, all of the servers can access all the data storage devices, or you can implement a zoning
configuration to restrict the access.
Example 4 shows a high-availability configuration in which a server is connected through two A54812-SW switches
to two input connectors on a JBOD.
Figure 13 Example 4, High Availability Configuration
This dual porting configuration gives the server a redundant path through the switches for high availability. If one
switch or connection fails, the server can still access the JBOD through the other connection.
Example 5 shows a large data storage network that includes two A54812-SW switches and several expanders.
NOTE
Expanders are either zoning expanders or non-zoning expanders. When SAS drives are attached to
a zoning expander, each drive can be zoned individually and each drive can be placed in its own
zone group. When SAS drives are attached to a non-zoning expander, they cannot be zoned
individually. All the drives behind a non-zoning expander must be in the same zone group as the
expander.
