RDF/IMP, IMPX, and ZLT System Management Manual

Preparing the RDF Environment
HP NonStop RDF/IMP, IMPX, and ZLT System Management Manual—524388-002
2-8
Specifying System Generation Parameters for an
RDF Environment
Reload of Backup Database.
If you need to reload the the backup database, you must change the UPDATEROPEN
parameter from Protected (the default value) to Shared. When you are done with the
reload, you should then change the UPDATEROPEN parameter back to Protected.
Views on the Backup System
If an application uses any NonStop SQL/MP shorthand or protection views on a
volume protected by RDF, audit data for transactions on the views refers only to the
underlying tables and not to the views. Views and their underlying base tables must be
present on the backup system after a takeover operation so that applications can
continue without interruption.
All base tables underlying the views must also reside on volumes protected by RDF on
the primary system.
Partitioned Tables and Files
If any partition of a partitioned NonStop SQL/MP table or Enscribe file exists on a
volume protected by RDF, then all partitions for that file should be on volumes
protected by RDF. The partitions of a file protected by RDF can reside on separate
systems, and all of the systems should be protected by an RDF network. Note that
these are not absolute requirements, but if you lose your primary system and must
takeover on your backup system, you might not have access to the data that is not
protected by RDF.
Specifying System Generation Parameters for an RDF
Environment
When performing system generation, you should do as follows:
•
Use the PATHPACKETBYTES modifier to enable the Expand Variable Packetsize
feature so that Expand will send large packets.
•
Use the CONGCTRL modifier to enable Expand congestion control.
You might also want to enable the multipacket frame feature, depending upon the type
of traffic that will be passed over the Expand path.
For best results, consider using the RDF Professional Service to assist you in defining
the Expand requirements for your RDF environment. Contact your service provider for
further details.
Designing Transactions for RDF Protection
When designing applications containing transactions that update databases protected
by RDF, you must consider the following restrictions that apply to the subsystem:
•
The effects of network (distributed) transactions after an RDF takeover operation