Expand Configuration and Management Manual (H06.21+, J06.10+)

Planning for ServerNet Clusters
Expand Configuration and Management Manual — 529522-013
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Configuration Considerations for Expand and
ServerNet Clusters
Configuration Considerations for Expand and
ServerNet Clusters
Major configuration considerations for Expand and ServerNet clusters include:
•
A route between two nodes that involves a change in technology invokes the use
of the Expand line handlers at every node along the route (including the source
and destination nodes). A change in technology might be a change from an
Expand-over-ServerNet line to an Expand-over-ATM line.
•
Every Expand system number and name must be unique across all networks that
can use Expand to communicate.
•
Each system in an Expand network can support up to 255 Expand line-handler
processes.
•
A node can only belong to one ServerNet cluster.
•
The Expand manager process, $ZEXP, must be configured and started.
•
The NonStop ServerNet cluster monitor process, $ZZSCL, must be configured and
started in all Integrity NonStop nodes connected to a ServerNet cluster.
•
As of G06.20, the Expand routing rules reverted to the use of simple time factors.
Super time factors, which were based on SPEEDK attributes, are no longer used.
SPEEDK values are now translated into line time factors that have values from 0 to
186.
•
You must evaluate the distance restrictions between cluster switches and
ServerNet cluster nodes during the planning process. Distance restrictions for
cabling ServerNet clusters are not shown in the topology examples in this section;
for more information on cable-distance restrictions in ServerNet clusters, see the
ServerNet Cluster Manual (for the 6770 switch) and the ServerNet Cluster 6780
Planning and Installation Guide .
Expand-over-ServerNet line-handler process modifier considerations include:
•
FRAMESIZE n modifier: This modifier must be the same for every Expand
line-handler process on every node in the Exp
and network.
•
PATHTF n, LINETF n, SPEEDK n, SPEED n, and RSIZE n modifiers: These
modifiers set the time factor (TF) for an Exp
and line. $NCP uses TFs to make
routing decisions. If PATHTF, LINETF, or RSIZE are specified, the value is the time
factor; if SPEEDK or SPEED is specified, the time factor is calculated.
LINETF is the recommended setting for ServerNet lines. P
ATHTF is equivalent to
LINETF for ServerNet lines. They each have a range of 0 to 186 to designate a
time factor in selecting the best lines and paths to other nodes; the smaller the
number, the more desirable the path.
When you use LINETF, you are setting the time factors directly
. For example, if you
prefer to use ServerNet as the best line and ATM as the second best line, you