Dell POWERVAULT MD3620F - Manual (Page 9)

Direct-Attached Cabling
Direct-attached cabling configurations provide simple, non-switched connections between the host server and storage
array. Redundancy is achieved in a direct-attached configuration if two RAID controllers are installed in the storage
array and multiple paths between the host sever and storage array are established.
A single RAID controller, direct-attached configuration is supported, but is not recommended due to the low level of
redundancy offered.
Single Controller Configurations
The following figures show two and four host servers, each connected to one RAID controller module. The host servers
share storage space without redundant paths. If one path fails, the host server on that path is disconnected from the
storage array.
NOTE: The MD Series Dense storage arrays do not support single-controller (simplex) configurations.
Figure 2. Two Host Servers With Dual Port HBAs Connected to a Single-Controller Storage Array
9