Specifications
© IBM Copyright, 2012 Version: January 26, 2012
www.ibm.com/support/techdocs 9
Summary of Best Practices for Storage Area Networks
development environments compared to the desired goal of stable operations for the
production side.
Switch vendors offer management tools and/or commands which can assist a SAN
administrator with planning and changing a zone configuration. When such tools are
available, the SAN administrator should make use of them as a validity check if for no
other reason. Switches will attempt to keep the impact of zone changes as local as
possible to just the edge devices that may be impacted by the changes.
However, if there are enough changes and/or the change scope is sufficiently large, the
fabric may respond by notifying all connected devices of a new zoning configuration. In
these cases, there is likely to be some minor fluctuations in traffic levels while the
individual edge devices respond to the state change notifications. As a result of this
potential impact, it is strongly suggested that changes to the zone configuration be
introduced during periods of low overall SAN traffic. In general, plan on approximately 2
to 3 seconds per active device port in the fabric before full stability after a significant
zoning change has been made.
Another general SAN best practice guideline is routine housekeeping. If a zoning
element (zoneset, zone, zone member, or alias) is removed from the active
configuration, delete the unused element when the zone configuration is changed. This
simple action will reduce potential confusion on the part of other SAN administrators as
well as any technical support personnel assisting with troubleshooting.
3 Fabric and Switch
A key maintenance operation to proactively monitor a fabric involves of clearing switch
and/or port statistics on a regular basis. Clearing statistics provides a simple baseline
of zero values for error counters. After clearing the error counters, the SAN
administrator will have a much easier time looking for non-zero values when performing
routine checks of switch operations. One important question arises with this practice
which is “how often should these statistics be cleared?”
In regards to fabric, there are two primary information sources that can be cleared: