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

Installing and Configuring RDF
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
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Configuring RDF
The SLOWMODE option value controls the frequency with which the receiver updates
its context records. With SLOWMODE on, the receiver updates its context records after
processing each extractor message buffer; this enables the updaters to have the lowest
possible RTD value at all times. The SLOWMODE option is intended for use when
customers have implemented their own pseudo-lockstepping environments. The default
is SLOWMODE off. For a complete discussion of SLOWMODE, see the description of
the SET RECEIVER
command in section 8.
To configure an RDF receiver process named $RECV to run as a process pair in CPUs 0
and 2 of the backup system at a priority of 185 with SLOWMODE off, and to have the
RDF image trail file (with a primary extent size of 3000 pages and a secondary extent
size of 3000 pages) reside on the volume $IMAGE, issue the following commands:
]SET RECEIVER PROCESS $RECV
]SET RECEIVER CPUS 0:2
]SET RECEIVER PRIORITY 185
]SET RECEIVER RDFVOLUME $IMAGE
]SET RECEIVER EXTENTS (3000,3000)
]ADD RECEIVER
You cannot start RDF until you have configured a receiver process.
You can issue ADD RECEIVER commands only when RDF is stopped.
Image Trails
As noted earlier, the RECEIVER RDFVOLUME option value specifies the disk volume
that contains the receiver’s master image trail. The receiver process writes all
commit/abort records to this volume. All updaters must be configured to secondary
image trails.
To create secondary image trails, use the ADD IMAGETRAIL command. Later, when
you configure your individual updater processes, you assign each of these processes to a
specific image trail. By spreading updaters across secondary image trails, you reduce the
number of updaters contending for a specific trail.
Each secondary image trail contains the audit records needed by the associated updater
processes. Image trail files in secondary image trails have the same extent sizes as image
trail files on the volume specified by RDFVOLUME.
Note. To have secondary image trails, you must add them after initialization and before RDF
has been started for the first time. Also you cannot add secondary image trails until you have
configured the receiver, as described in the previous paragraphs. The secondary image trail
files have the same extents as the master image trail files. To delete a secondary image trail,
you must stop RDF, delete any updaters associated with the particular trail, and then delete the
trail. Normally, you should never delete a secondary image trail until RDF has completely
caught up with TMF.