Dell PowerVault MD3000 - Manual (Page 51)

Using Your RAID Enclosure
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This cabling topology, when used with alternate path software, ensures a redundant path from the host
server to the virtual disks. If the connection from In-0 on the RAID controller to the host port becomes
unavailable, the alternative path software will transfer I/O activity on RAID controller module 0 to RAID
controller module 1. While RAID controller module 0 is unavailable, the host can access all virtual disks
through RAID controller module 1.
One Host with Four Cable Connections
Figure 3-2 shows one host with two HBAs. Both HBAs have two ports. Each HBA port is connected to
one of the RAID controller modules in the RAID enclosure. Each RAID controller module has two ports.
Figure 3-2. One Host with Four Cable Connections
This cabling topology, when used with alternate path software, ensures a redundant path from the host to
the virtual disks. If any component (HBA, HBA port, cable, RAID controller module port, or RAID
controller module) fails, the host can still access the virtual disks through an alternate path.
NOTE:
This configuration is the most redundant for one host directly connected to a single array module.
Two Hosts, Each with Two Cable Connections
Figure 3-3 shows two hosts. Each host has two HBAs. (Both HBAs may have two ports, but in this figure
use only a single port.) Each HBA is connected to one RAID controller module in the RAID enclosure.
Each RAID controller module has two ports.
dual-HBA host server
RAID controller module 0
RAID controller module 1
MD3000 RAID Enclosure