RDF System Management Manual for J-series and H-series RVUs (RDF 1.10)

Sizing the RDF configuration is a complex task that is best carried out by HP personnel. Those
personnel can assist you in configuring and sizing your RDF environment using tools and utilities
designed and developed as part of the RDF Professional Service.
Contact your service provider for further details.
Disk Volume Limit
The RDF/IMP, IMPX, and ZLT products can protect up to 255 physical or virtual volumes on your
primary system, and the updaters for these volumes replicate to either a single physical or virtual
disk on the backup system.
Volume-to-Volume Mapping
The recommended disk drive configuration for RDF products is a one-to-one mapping between the
primary volumes and their corresponding backup volumes, with mirrored disks on both systems.
This one-to-one mapping ensures that each partition of a partitioned file or table is mapped
appropriately to a backup volume.
Volume names on the backup system can differ from those on the primary system, but the use of
identical primary and backup volume names prevents naming conflicts after a takeover operation.
If the names of the backup volumes are different than those of the corresponding primary volumes,
you must change all volume references before the primary system’s applications can start on the
backup system.
Subvolume-to-Subvolume Name Mapping
RDF can replicate data from subvolumes on the primary system to same or differently named
subvolumes on the backup system. For more information, see Chapter 12 (page 271).
Expand (Data Communication) Resources
RDF sends filtered audit data from the primary system over the network to the backup system. A
communications path between the systems can be any form of Expand linkage. Plan to configure
sufficient communications resources between the primary and backup systems so that RDF can do
the following:
• Handle the peak rate of audit data
• Catch up processing in any audit trail if the communications paths go down and are restored
(without RDF reinitialization)
If you are using a dedicated Expand path with high throughput, you should set PATHPACKETBYTES
to 8192. If you are not using a dedicated Expand path, you should use Multipacket frames with
PATHBLOCKBYTES set to 8192. See also “Specifying System Generation Parameters for an RDF
Environment” (page 58).
RDF is designed to extract audit records from the primary system and transmit it to the backup
system as quickly as possible. If you are not using the ZLT capability, this limits the number of
transactions that could be lost if a disaster should occur at the primary system. See Unplanned
Outages Without ZLT in Chapter 1 (page 27).
To estimate the data communications resources needed for RDF, calculate the amount of audit trail
data generated per second during peak loads. If your business has seasonal peaks, such as
holidays or the ends of calendar quarters, consider the peak rate at those times.
The discussion that follows pertains to the Master Audit Trail (MAT). If you are replicating auxiliary
audit trails, you should use the same algorithm for each auxiliary audit trail.
Use the following sampling process once an hour for two weeks to establish your needs:
Configuring Hardware for RDF Operations 53