Selecting Interconnect Module Types; Connecting With Pass-Thru Modules - HP BL685c - ProLiant - 4 GB RAM Connectivity Manual

Selecting interconnect module types

The optimum type of interconnect module for use in a system will be determined by several factors
such as SAN proximity, fabric size, number of server blades to be connected, and performance and
availability goals. Pre-existing SAN attributes also affect the choice of interconnects.

Connecting with pass-thru modules

The HP 4Gb FC Pass-Thru Module provides a solution for connecting server blades to a SAN when
the customer does not want to deploy Fibre Channel switches in the BladeSystem enclosure. Such a
choice may increase the number of SFPs and optical cables used. This solution may be desirable if
only a small number of the server blades in the enclosure will ever require a SAN connection. Each
pass-thru module provides dedicated paths between up to 16 server blades and an equal number of
SAN switch ports or SAN target ports.
Note that the one-to-one nature of the pass-thru module means that connecting an external port
directly to a SAN device will provide only one FC path for a server blade. A typical infrastructure
would include an external switch that connects the pass-thru ports to the SAN device. For redundant
paths between a server blade and a SAN device, two pass-thru modules and two external SAN
switches are required.
There is a direct relationship between the server HBA ports and the external ports on the pass-thru
module. No switching is provided by a pass-thru module. Each server HBA port has only one external
port available on a pass-thru module.
Figure 9. Pass-thru connectivity for the HP BladeSystem c-Class enclosure
HP BladeSystem c-Class enclosure
Internal FC ports 1-16
to server blades
(devices 1-8, port 1)
(devices 9-16 port 1)*
Internal FC ports 1-16
to server blades
(devices 1-8, port 2)
(devices 9-16, port 2)*
*c7000 enclosure only
†
c3000 enclosure only
Note that mapping is direct between the device bays (server blades) and the external ports on each
pass-thru module (HBA in server 1 to external FC port 1, HBA in server 2 to external FC port 2, etc.).
HP pass-thru
interconnect
module
(bay 2 † , 3, 5*, or 7*)
HP pass-thru
interconnect
module
(bay 2 , 4, 6*, or 8*)
†
External
FC Ports 1-16
External
FC Ports 1-16
13