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

Managing RDF
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
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Doing FUP RELOAD Operations With Updaters
Running
Doing FUP RELOAD Operations With Updaters
Running
Because the backup database is audited by TMF, you cannot do FUP RELOAD
operations on it unless you have set the updater access mode to shared by using the
UPDATEROPEN parameter of a SET RDF or ALTER RDF command.
The default is protected access.
Protected access is strongly recommended, except when you specifically wish to do a
FUP RELOAD on the backup database with the updaters running.
To do a reload on the backup database while the updaters are running, do as follows:
1. Stop the updaters (issue a STOP UPDATE command on the backup system).
2. Alter the UPDATEROPEN attribute of the RDF configuration to SHARED:
ALTER RDF UPDATEROPEN SHARED
3. Restart the updaters (issue a START UPDATE command on the backup system).
4. Initiate the reload.
After the reload is finished, you should change the access mode back to protected, as
follows:
1. Stop the updaters (issue a STOP UPDATE command on the backup system).
2. Alter the UPDATEROPEN attribute of the RDF configuration to PROTECTED:
ALTER RDF UPDATEROPEN PROTECTED
3. Restart the updaters (issue a START UPDATE command on the backup system).
Exception File Optimization
Each updater maintains an exception file in which it identifies every audit record that
must be undone on the backup database during a takeover. Typically records must be
undone because the outcome of the associated transaction is unknown. When protecting
auxiliary audit trails, however, the outcome of a transaction might be known (a
COMMIT record is present in the Master Image Trail), but there is no way of knowing
for certain that all the associated audit records were successfully replicated to the
auxiliary image trail prior to the takeover.
If you are protecting only MAT volumes, the amount of undo required during a takeover
is usually small. If one or more long-running transactions are active at the time of a
takeover, however, the amount of undo required can increase substantially (depending
upon the amount of audit records generated by those transactions).
If you are protecting auxiliary audit trail volumes, a considerable amount of undo could
also be required if any of the extractor-receiver pairs (master or auxiliary) falls behind
the others prior to a takeover.