RDF/IMP and IMPX System Management Manual (RDF 1.3+)

Entering RDFCOM Commands
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
8-10
Command Overview
[VOLUME] $volume
applies configuration parameters for an updater process, implicitly identifying the
updater process by the name of the volume on the primary system for which this
process is responsible. The updater volume must be audited by TMF.
Where Issued
Primary system only.
Security Restrictions
You can issue the ADD command only if you are a member of the super-user group.
RDF State Requirement
Except for the ADD VOLUME command, you can issue any ADD command only after
initializing RDF but before entering the first START RDF command. After RDF is
initialized, you can issue an ADD VOLUME command anytime RDF is stopped.
Usage Guidelines
With the ADD command, all configuration parameter settings that you previously
supplied in SET commands for the particular process or other object are applied from
the RDF memory table to the RDF configuration file. Any parameter settings that you
did not supply are set to their default values.
Each volume on the primary system protected by RDF requires a corresponding updater
process on the backup system. You must issue one ADD VOLUME command for every
primary system volume to be protected by RDF.
Although more than one primary volume can be protected by a single disk volume on
the backup system, Compaq strongly recommends that you configure your environment
so that each updater process writes to its own volume (that is, that there is a one-to-one
mapping of primary volumes to backup volumes).
If you add an updater process after you stop RDF, the context record of the new updater
process is set to that of the receiver’s context for particular image trail of the updater.
So, after the next START RDF command, the newly added updater process begins
reading from the current image file at the same place that the receiver process begins
writing.
Caution. If a double CPU failure occurs, causing loss of the extractor, you must not add any
disk volume to the RDF configuration between the time the extractor is lost and the time RDF is
restarted. Adding a volume during that interval could invalidate database synchronization.
Caution. After RDF is configured and running, do not add an updater process unless a STOP
TMF command has shut down RDF; otherwise, you cannot be sure that the data on the newly
added backup system volume is synchronized with the data on the corresponding primary
system volume.