RDF/IMP and IMPX System Management Manual (RDF 1.4+)

Preparing the RDF Environment

HP NonStop RDF/IMP and IMPX System Management Manual—524388-001

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Data Communication (Expand) 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 didicated Expand path, you

should use Multipacket frames with PATHBLOCKBYTES set to 8192. (See also

Specifying System Generation Parameters for an RDF Environment.)

RDF is designed to extract audit information from the primary system and transmit it to

the backup system as quickly as possible, limiting the number of transactions that

could be lost if a disaster should occur at the site of the primary system. If RDF has to

wait for the Expand subsystem, RDF might not be able to stay current with transactions

occurring on the primary system.

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. 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:

1. Enter a FUP INFO command for the current TMF MAT and record the end-of-file

(EOF) value; for example:

FUP INFO $AUDIT.ZTMFAT.*

2. Enter a FUP INFO command for the current MAT 5 minutes later and record the

EOF value; for example:

FUP INFO $AUDIT.ZTMFAT.*

3. If all the TMF audit data is generated on volumes protected by RDF, subtract the

first EOF value from the second EOF value to obtain the number of bytes

CODE EOF LAST MODIF OWNER RWEP TYPE REC BLOCK

$AUDIT.ZTMFAT

AA000003 134 11292672 10:05 -1 GGGG

CODE EOF LAST MODIF OWNER RWEP TYPE REC BLOCK

$AUDIT.ZTMFAT

AA000003 134 11653120 10:10 -1 GGGG