RAID Subsystem
5.3 | Host Connection Topology | |
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Fig. 5.2 Cascaded Subsystems Connected to Two Host Computers
In the example shown in Figure 5.2, the SCSI ports are connected to different host computers. This provides both path and host computer redundancy. If one of the host channels becomes disconnected, or if the cable connecting one of the host ports to the host computer is dam- aged, the second path can transmit data from the subsystem to one of the host computers. Similarly, in the clustered hosts configuration, the same array can be accessed through differ- ent data paths and downtime will be minimized.
To obtain more disk capacity, the “Out” ports are used to cascade another subsystem. The
1.Directly to servers or workstations equipped with SCSI HBAs.
2.Connect two subsystems on the same host buses for a larger combined capacity.
3.
High availability configurations, such as clustering or redundant paths settings, can be applied with adequate software control. The same logical array can be associated with two or more different host IDs to facilitate access down through different HBAs.
Default Channel Settings
Model | Host Channels | Drive Channels |
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| Channel 0 and Channel 1 | Channels 1 to 8, each dedicated to |
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| one connected drive |
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Table 5.1 Default Channel Settings |
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Bosch Security Systems | F.01U.027.797 V2 2008.08 |