Specifications

© IBM Copyright, 2012 Version: January 26, 2012
www.ibm.com/support/techdocs 25
Summary of Best Practices for Storage Area Networks
Within a particular adapter, the ports should be selected based on the port group
(0/1 and 2/3). The 4-port adapter in the DS8300 are oversubscribed on port group
boundaries
• 4-adapter/8-port configuration, 4 port-0’s and 4 port 2’s
• 8-adapter/16 ports, 8 port-0’s and 8 port-2’s
If two SVC clusters share a common DS8000 storage system, they should use
separate paths per SVC cluster per DS8000 host adapter. (E.g. SVC A uses ports 0
and 2, while SVC B uses ports 1 and 3.) More than two clusters should not share
the same DS8300.
Additional information on best practice considerations for IBM DS8000 used in
conjunction with SVC can be found in the “DS8000 with SVC Best Practices”
TechDoc ID PRS4465.
5 Cable Plant
With most fiber cabling used in the data center today, information transfer occurs in two
directions simultaneously. This method uses 2 optical fibers contained in a single fiber
optic cable and physically connects to ports at each end which houses the transmitter
and receiver in a single assembly. The fiber element within an optical cable usually
consists of a glass core and a cladding. The glass core provides the light path, the
cladding surrounds the core, and the optical properties of the core and cladding junction
cause the light to remain within the core. Although the core and the cladding diameters,
expressed in micrometers (µm), are often used to describe an optical cable, they
actually indicate the physical size of the fiber element.
Mishandling a fiber optic cable will lead to microscopic internal faults within the glass
core. In some cases this can cause a complete failure of a cable. Often, faults result in
intermittent problems that require a specific cable orientation. This type of fault can be
difficult to isolate There are a number of precautions that should be taken when
handling fiber optic cables.
• Make sure the cable cutouts in the floor tiles have the appropriate protective
edging.
• Route the cables away from any sharp edges or projections that could cut the
outer jacket.