RDF System Management Manual for H-Series and J-Series RVUs (RDF 1.9)

One set of disks can be replicated to another set of target disks to provide a copy of the live
database. There are two operational considerations unique to this environment:
• The updaters operate in transaction mode, which means you should not stop TMF before
stopping RDF.
• The RDF takeover operation cannot be performed unless you manually stop the monitor
and extractor processes before issuing the TAKEOVER command or include the ! option in
the TAKEOVER command.
Online Product Initialization
You can initialize RDF/IMP, IMPX, or ZLT while your applications continue to run. This is
particularly useful for installing new versions of RDF into existing production environments
where you cannot afford to stop your applications even briefly to generate a TMF shutdown
timestamp. It is also useful if you encounter a problem for which you would like to reinitialize
RDF without stopping your applications.
For information about this capability, see:
• “Initializing RDF Without Stopping TMF (Using INITTIME Option)” (page 80)
• “Online Installation and Initialization Without Stopping RDF” (page 82)
• “INITIALIZE RDF” (page 212)
Online Database Synchronization
With RDF/IMP, IMPX, or ZLT you can synchronize entire databases or selected volumes, files,
tables or even partitions while your applications continue to run. For information about this
capability, see Chapter 7 (page 167).
Online Dumps of the Backup Database
With RDF/IMPX or ZLT, all backup databases are audited by TMF. You can take online dumps
of a backup database at any time, thereby minimizing the amount of time necessary to perform
any subsequent takeover operation. For information about taking dumps while the updaters are
running, see Chapter 5 (page 121).
Subvolume-Level and File-Level Replication
By default, RDF provides volume-level protection, wherein changes to all audited files and tables
on each protected primary-system data volume are replicated to an associated backup-system
data volume.
RDF/IMP, IMPX, and ZLT also support subvolume-level and file-level replication. To use this
capability, you supply INCLUDE and EXCLUDE clauses when configuring updaters to identify
specific subvolumes and files you want either replicated or not replicated.
For information about subvolume-level and file-level replication, see Chapter 11 (page 279).
Shared Access DDL Operations
RDF includes two event messages (905 and 908) that assist you in the proper performance of
NonStop SQL/MP shared access DDL operations on the backup system. See “Performing Shared
Access DDL Operations” (page 152).
Configurable Software Location
By default, RDF software resides on $SYSTEM.RDF. You can, however, override this location
when you configure RDF. When you configure the general RDF attributes, use the SET RDF
SOFTWARELOC command. This can be useful if you have different releases of RDF on your
system.
54 Introducing RDF