HP NonStop RDF, Management Manual

Page: 243 / 478

START RDF [, UPDATE {ON | OFF}]
UPDATE ON
Enables update processing on the backup system; this is the default value.
UPDATE OFF
Disables update processing on the backup system.
RDF image files are not purged from the backup system.
Where Issued
Primary system only.
Security Restrictions
You can issue the START RDF command if you are the member of the super-user group that
initialized RDF and have a remote password from the RDF primary system to the backup.
RDF State Requirement
You can issue the START RDF command only after TMF has been started and RDF has been
previously initialized.
Usage Guidelines
The decision to start RDF is a management decision that should be carefully planned and
performed. Operators should never issue this command strictly on their own initiative.
For information about when to use the START RDF command and how it affects the primary
and backup databases, see
“Restarting RDF” (page 136) .
If you have initialized the TMF and RDF subsystems before issuing the START RDF command,
RDF automatically begins transmitting audit data from the beginning of the first audit-trail file.
CAUTION: If you initialize RDF after a STOP RDF command is issued at the primary system,
you might need to resynchronize the databases before restarting RDF.
TMF must be started and transactions enabled on both primary and backup systems before you
issue the START RDF command.
When RDF starts, it automatically executes an implicit VALIDATE CONFIGURATION command
with these results:
• If any parameter value in the RDF configuration file is invalid, RDFCOM displays an error
message, and the START RDF operation fails.
• If all of the parameters in the RDF configuration file are valid, RDF copies the configuration
file from the primary system to the backup system, displays any warning messages, and
starts the RDF processes.
After all RDF processes start, RDFCOM prompts you for your next command.
NOTE: RDF always starts with updating enabled unless you explicitly specify UPDATE OFF.
This scenario is true even if updating was disabled when RDF was last stopped.
The extractor, receiver, purger, RDFNET, and updater processes are restartable. That is, none of
these processes rely on checkpointed information. If the primary process fail, the backup reads
its context from disk and resumes operations. If a process pair should fail completely (for example,
a double CPU failure), then the RDF monitor aborts all other processes. When you restart RDF,
all processes obtain their starting information from context on disk, and this ensures an accurate
restart and eliminates the possibility of data corruption in the backup database. For more
information about how these processes support restartability, see
“Processor Failures” (page 127) .
RDFCOM Commands 243