The storage subsystem supports a fiber-optic interface for host and storage
expansion enclosure connections. Youmust install a Small Form-factor Pluggable
(SFP) module in each interface connector on the controller where a fiber-optic cable
is to be installed. Do not install an SFP in any port that will not have a fiber-optic
cable attached. Remove any SFP from any port that does not have fiber-optic
cables attached.
The DS5020 storage subsystem host ports support 2, 4, and 8 Gbps Fibre Channel
speeds. The DS5020 storage subsystem drive ports support only 4 Gbps Fibre
Channel speeds.
Attention: The maximum operating speed of the Fibre Channel port is determined
by two factors: the speed of the SFP module that is installed and the speed of the
Fibre Channel connection. For example, a 4 Gbps SFP that is plugged into a 8
Gbps-capable port will limit the speed of that port to a maximum of 4 Gbps.
Conversely, an 8 Gbps SFPthat is plugged into a 4 Gbps-capable port will limit the
speed of the port to a maximum of 4 Gbps. Carefully check the SFP IBM part
number, option number,and FRU part number to identify its speed. There are no
physical features that distinguish an 8 Gbps SFP from a 4 Gbps SFP.
Figure 8 shows an example of SFP module with fiber-optic cable.
Note: The SFP module and the fiber-optic cable shown are for illustrative purposes
only.The actual SFP module and the fiber-optic cable shape might look
different from the figure shown.
Software and hardware compatibility and upgrades
The latest DS5020 controller firmware and NVSRAM, the storage expansion
enclosure drive enclosure ESM firmware, and Fibre Channel and SATAdrive CRUs
firmware must be installed to achieve optimal functionality, manageability,and
reliability.
Unless stated otherwise, you can find the latest DS5020 publications, firmware, and
host software at the IBM System Storage Support Web site:
http://www.ibm.com/systems/support/storage/disk
Figure8. SFP module and fiber-optic cable
Chapter1. Introduction 17