Specifications

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Summary of Best Practices for Storage Area Networks

configured into multiple virtual switches and each virtual instance has a different

Domain ID, the inclusion of a Domain ID in the switch name is not suggested. Switch

Domain IDs within redundant fabrics should be unique between the fabrics if at all

possible. This practice allows administrators and product support specialists to review

data from edge devices (servers or storage systems) and be able to quickly determine

which fabric and switch a specific device port is a member.

Switches in a common fabric should have similar code and/or firmware levels whenever

possible. Having a fabric comprised of ten switches of the same model and type

running nine different code levels is a recipe for problems. Vendors perform extensive

testing of new code versions prior to public release, but most test plans do NOT include

scenarios involving different code levels unless there are known situations and/or

configurations. One such example involves newer hardware being tested with a new

code level where the fabric also contains one or more switches with older hardware

which has a “ceiling cap” of some older code version. In these interoperable test

scenarios, the release notes for the higher code level will specific information about the

older hardware platforms and code level(s) were used during testing.

Switch configuration parameters within the same fabric should be consistent. One

example is the time-out parameters such as R_A_TOV. For some of these parameters,

the switch will not merge into the fabric unless they are the same values and the

resultant error messages will provide information to be able to quickly resolve the

parameter mismatch. However, some switch parameters can be different from one

switch to another within the same fabric and connectivity and/or performance issues

may not be as easy to troubleshoot.

When ports are not in use on the switch, please keep the port cap inserted in the port.

Port caps are provided to keep both dust and light contamination within a port to a

minimum. If dust particles or other small debris items are able to get inside the physical

connector while not in use, later attempts to activate and use the port may be

problematic due to a poor connection.

Ports not in active use should be administratively disabled. The reasoning for this

recommendation is that disabled ports will not generate and/or log spurious, phantom

errors which can be misleading. When a switch port is activated, allow the attached

device to negotiate to its desired port speed and then hard configure the switch port for

that port speed. This action will reduce the time for the remote device port to

synchronize in the future. At the time a switch port is activated, configure a meaningful

descriptor for the switch port. Examples of port descriptors include: