HP NonStop RDF, Руководство по управлению

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500 kilobytes of audit records is missing on \C.
Because \C has the least amount of audit records, you must issue this command on \C:
COPYAUDIT, REMOTESYS \B, REMOTECONTROLSUBVOL A1
For each image trail, RDFCOM on \C reads its own context file to determine the MAT position
of the last audit record in the trail. RDFCOM then searches the corresponding trail on \B to find
that audit record and performs large block transfers to move all audit records beyond that point
to the trail on \C. As it does this, RDFCOM issues messages to let you know which image trail
it is currently processing.
NOTE: When it begins copying missing audit records from one system to the other, RDFCOM
never alters any of the existing image trail files on the local system. Instead, it creates a brand
new image file on the local system even if the starting point of the missing audit records on the
other system is in a file with a different sequence number. This means that, upon completion of
the COPYAUDIT operation, the local system will almost always have more image trail files (one
or two per image trail) than the other system. This is expected behavior.
If the takeover completes successfully (the receiver logs an RDF message 724 followed by a 735
message containing the same detail as in the 735 message associated with the takeover on \B),
the two databases are logically identical.
At that point you can initialize, configure, and start RDF on both systems and then resume
application processing on the new primary system with full RDF protection.
COPYAUDIT Restartability
The COPYAUDIT command is restartable.
If an error condition aborts execution of a COPYAUDIT command, you merely correct the
condition and then reissue the command. Upon restart, RDFCOM quickly checks the local system
image files it had previously created to be sure they are still correct, deletes the file it was working
on at the time of the error condition, and then resumes copying. Because it keeps track of where
it was in the COPYAUDIT operation, RDFCOM does not have to recopy the previously copied
image files.
RDFCOM abends if it encounters network problems while searching the remote image trails for
missing audit records. If that happens, RDFCOM logs a message to the EMS event log, but not
to the home terminal.
If RDFCOM encounters network problems during any other phase of COPYAUDIT execution,
it does not abend. Instead, it logs a message to the home terminal and aborts the COPYAUDIT
command.
Using ZLT to Achieve Triple Contingency Protection for Auxiliary Audit
Trails
The COPYAUDIT command does not support auxiliary audit trails.
With the RDF/ZLT product, however, you can achieve the same protection without using a
COPYAUDIT command, and thereby protect RDF environments that include auxiliary audit
trails.
Triple Contingency Without ZLT
The triple contingency feature builds upon the ability to replicate to multiple backup systems.
With this feature, you establish two essentially identical RDF configurations:
RDF Subsystem #1
\A ---------> \B
COPYAUDIT Restartability 275